Professor Louis Davies received a BSc Hons from the University of Sydney in 1948 and was awarded a Rhodes Scholarship to study plasma physics at Oxford University, for which he received a DPhil in 1951. Returning to Australia, he joined the Division of Radiophysics of CSIRO. In 1958 Professor Davies visited the Bell Laboratories on a Commonwealth Fund Fellowship. After returning to work at CSIRO for several years, he became chief physicist at Amalgamated Wireless Australasia (AWA) from 1960–85. He combined this position with a professorship of electrical engineering at the University of New South Wales from 1965-84.
Interviewed by Professor David Craig in 1999.
Lou, could we begin with your early years and your family background?
I was born in Sydney but at only about six months of age I moved to Aberdeen, in the Upper Hunter, where my father was general manager of the local meatworks. In those days Aberdeen was a three-pub town of about a thousand people, with a police station and a public school, which I attended. Because of the numbers there were only three classes: 1st/2nd combined, 3rd/4th, and 5th/6th.
Davies is a Welsh name, isn’t it?
Yes. My grandfather was born in Carmarthen, Wales. He studied medicine at Liverpool University, then came out and set up practice in Esk, Queensland, where my father was born. Grandfather was a highly qualified medico for those days, particularly in a part of the world like Esk. He died from TB when Dad was only about 18 months old and the family had a very rough time economically.
I think your father became a soldier in the First War.
Yes, in the 7th Australian Light Horse Regiment, which initially was on Gallipoli. When he arrived, the regiment was re-forming south of Cairo. They then fought principally against the Turks, right across the Suez and up through Syria and Palestine to Amman, north-east of Jerusalem. He had quite a long stint, about four years, ending up as adjutant of the regiment.
And your mother?
My mother was born in Dunedin, New Zealand, and had quite a distinguished career. She was a concert pianist who trained at the Conservatorium in Sydney, and later she became a brilliant contract bridge player. She is still alive, aged 100 – for which she has had a letter from the Queen, the Governor-General, the Prime Minister, the Premier, everyone.
After the Aberdeen primary school you went to a number of secondary schools.
Yes. The first was Muswellbrook District Rural School, where we had very practical subjects – woodwork, metalwork, agriculture I and II. My agriculture teacher used to stray well beyond the syllabus and get us interested in all sorts of things. I became a Junior Farmer and developed a great interest in horses (I learnt to plough behind a horse) and chooks. But I’ve never been really fond of chooks. Then I went to Maitland High and later to Shore, in Sydney.
Where does the science and engineering in your life start?
Well, engineering not till I left Shore, after the Leaving Certificate. But I think I was always interested in science. I had an interest in electricity. We had a wonderful man working around the home in Aberdeen who used to subscribe to Popular Mechanics and was forever making – out of quite impossible bits of material – motors, generators, etc., all of which fired one’s interest a bit. And my parents provided me with a couple of chemistry sets while I was at Muswellbrook and Maitland high schools. I used to construct flying model aircraft, too. So it was a good background.
Mathematics was probably always my strong subject at school. I had the great good fortune to have good teachers at Shore. Particularly, L C Robson, the headmaster, taught me for two of my four years there, and I also remember an experiment in which Clem Tiley got us to measure the mechanical equivalent of heat – it came to me as a bolt from the blue that mechanical work could be transformed into heat.
You began at the University of Sydney in 1941, but the war was on and you wanted to be involved.
Yes. At the end of 1941 the Japanese attacked Pearl Harbor and a lot of us enlisted. The university manpower officer, bless him, wanted me to become a radar officer but I thought it would be much more exciting to get into aircrew. I enlisted and passed the medical tests, but you had to queue up to get in. So for nine months I lived at home and worked in the meatworks, at first in the office and then, when they found I had some engineering experience, with the chief engineer.
One went into the Air Force as an aircrew trainee, being then sent to pilots’ or observers’ or wireless operator/airgunners’ school. I was sent off to the observers’ school at Cootamundra, where I learnt to navigate. After a bombing and gunnery course at Evans Head and an astronavigation course at Parkes, I was commissioned and went to general reconnaissance school at Bairnsdale and then Operational Training Unit at Sale. There we formed a crew in the Australian-made Beaufort aircraft in which we later flew with 1 Squadron from Gould strip, near Batchelor, south of Darwin. We made reconnaissance flights looking for Japanese shipping as far out as south of Java, or off Merauke in New Guinea. Occasionally we were let loose to drop some bombs on the Japanese in places in Timor like Dili and Koepang. The most useful thing we did was to drop stores to our troops in the hills in the eastern end of Timor.
In 1945 you resumed university mathematics.
By then I was in a transport squadron. The University of Sydney had a wonderful scheme of external studies for members of the armed forces, and so I did Mathematics II, advanced, in 1945 – sitting for the exams in a tent in Morotai, near the equator, in the middle of a coconut plantation. Something must have clicked, because I actually got a Credit. I felt very proud of myself.
1945 was also the year of your marriage, wasn’t it?
Yes. June and I were married in September 1945. We had known each other since we were about 12, having both grown up in the Aberdeen area. June lived well out of town and had a governess for her primary schooling but she then went to boarding school in Sydney, and later became an Army driver at Victoria Barracks.
Because of the war one could be awarded the Rhodes Scholarship even though one were married, and those three years in Oxford with June, from 1948 to ’51, were some of the most influential and rewarding (as the Americans would say) years of my life.
Your first child was born in Oxford. Tell us about your children.
They have all done pretty well. Our elder son, Sandy, did rural science at the University of New England and is national sales manager of a metals company, making good use of his academic background. Our second son, Gordon, is the genius of the family. He is a senior systems analyst, responsible for one of the products of a very successful local Australian software company, and seems to fly a great deal to countries from India to Korea. Our daughter, Fiona, did a Bachelor of Applied Science at the University of New South Wales in textile technology, and is now a very successful consultant in commercial textiles. All three are married, with children.
In Oxford you worked at the Clarendon. What were your main research activities?
I studied for a DPhil degree – that is a PhD in every other university except Heidelberg, I think – in plasma physics. I worked with Peter Thonemann, an Australian who had some brilliant ideas about possibilities for thermonuclear fusion. He thought that one could constrain a plasma by subjecting it to a longitudinal magnetic field, preventing the ions from escaping laterally. He devised a technique using the radiation which is emitted by electrons in the plasma when they recombine with ions in the vapour of the element caesium, and so for three years I did various experiments on caesium discharges with a longitudinal magnetic field – provided by a generator which the laboratory had bought very cheaply from the Birmingham Tramways.
My supervisor was Dr Heinrich Kühn, a spectroscopist, because my study involved looking spectroscopically at the light emitted from the caesium discharge when the electrons recombined with the ions. Regrettably, the results of my experiments showed that a longitudinal magnetic field had quite the reverse effect on constraining a plasma. As far as I am aware at this stage (I did the experiments a long time ago) that is due to the instabilities which are generated in the plasma when you subject it to magnetic fields. But a lot of thermonuclear fusion research during the succeeding 50 years has been aimed at trying to constrain plasmas – with ever more expensive pieces of equipment, as far as I can see.
At Oxford you continued your sports interests which had begun at school, didn’t you?
Yes. I had never been much good at moving at speed but with my long legs I was able to do reasonably well for a young boy in the high jump, first at Maitland and then at Shore, where finally I jumped in the State junior championships and came second, I think. It was a long while ago!
I rowed at Shore, first of all in the House Tub Fours. We used to row down on Sydney Harbour and get ourselves mixed up with all sorts of huge ships. In 1940, at the shed at Gladesville, I rowed in the Second Four, which I am happy to say won their race. But that was the first year for some time at Shore in which the Eight and the First and Second Fours weren’t all won by the School – we missed out on the Eight.
At Sydney University I went on with athletics, getting involved also in the hop-step-and-jump, a strange event of Irish origin in which physicists, strangely enough, always seem to have done well. The world record is held by a British physicist.
And in the RAAF?
At Bairnsdale, where I was in general reconnaissance school, there was an opportunity to row. Bairnsdale in early days was a great force in Australian rowing. There were a couple of Eights down in the shed there, so eight of us with a cox got together in the RAAF station. We put the commanding officer in at no.2, where he wouldn’t do too much harm to the rowing, to ensure that we got some time off to row. We used to row from Bairnsdale down to Lake Wellington, cook some chops and drink some beer, and row back again. And we had a couple of competitive regattas with neighbouring Air Force stations.
Didn’t you come back to high-jumping in Oxford?
Yes. There were one or two episodes of high-jumping in the Air Force, but in Oxford it was great fun and also I found over there that you had much more chance of getting worthwhile trips. The Oxford and Cambridge team went to the United States and Greece; with the English and Welsh team I went to Belfast; and I had a trip with the Oxford and Cambridge team to Dublin – all of which broadened one’s mind.
How was it that you were appointed to CSIRO?
I came back from Oxford without a job but hoping to carry on with some aspect of plasma physics. But being offered only a very poorly paid job in that field, and having a wife and child to support, I looked instead for a strong group of physicists to join. That quite clearly was the Division of Radiophysics of CSIRO, in Sydney. I had previously been in touch with Dr Bowen, the Chief of the Division, and now I had a long discussion there with Dr Joe Pawsey, the Deputy Chief, who offered me a job in the Radioastronomy Group. The pay was at the absolute bottom of the scale but I accepted it gratefully and worked on getting myself up to speed in radioastronomy.
Reading a theoretical paper on the origin of microwave noise from the atmosphere of the sun, I thought we could make something approximating to that in the lab. With the help of the neighbouring Division of Electrotechnology, I got some experiments started on looking at the noise radiation from the positive column of a gas discharge, or plasma. We did some microwave measurements and then became interested in doing them at considerably lower frequencies. We had the equivalent of a resonating garbage can with a gas plasma in the middle of it, from which we managed to learn some interesting facts about electron interactions in a plasma, at the same time providing some reinforcement to the theory of the origin of microwave radiation in the solar atmosphere.
At the end of those studies, Taffy Bowen said to me in the lab one day, ‘Lou, I would like you to do some work on these newfangled transistors and germanium’ – of which at that stage they were all made, germanium being an elemental semiconductor. I was initially a little reluctant, but he said he could arrange for me to go to Bell Telephone Laboratories in the United States, where the transistor had been invented only five years previously, in 1948. (He had established a firm friendship with Dr Jim Fisk, head of the Bell Telephone Labs.) So poor Shockley, Brattain and other members of technical staff were saddled with this guy from Down Under for a whole day each, introducing me to some of the mysteries of solid-state physics as exemplified by germanium and transistor work.
That trip actually extended longer than two weeks, I think.
It certainly did! Six weeks altogether. Taffy Bowen had said, ‘You’ll have financial support for about two weeks, but make it last as long as you can!’ I managed to establish contact with Dr Malcolm Hebb, head of the research labs of General Electric Company, in Schenectady, New York. Our friendship then lasted for many long years. Also, at lunch there on my first day I happened – to my great delight – to meet Irving Langmuir, one of the alumni of Dr Hebb’s laboratory. He was a famous physicist on many counts and a Nobel Prize winner who turned out to have some interest in the way Australians had coped with the problems of prickly pear, a cactus. Well, in my youth I had seen quite a lot of prickly pear around Aberdeen, with the unsuccessful attempts to use cochineal against it and finally the Cactoblastis successes, so Langmuir and I had a long conversation about that. We corresponded for a while afterwards and I sent him some material from CSIRO. That was an interesting and very rewarding departure from my main purpose for being in the States.
Tell us something of the Radiophysics Division of CSIRO to which you returned.
Taffy Bowen was Chief of the Division, one of his particular interests being rainmaking. The research and support staff included Joe Pawsey, Jack Piddington, who is a Fellow of the Academy, Paul Wild, Chris Christiansen, Bernie Mills, Maston Beard, who had a great deal to do with the first CSIRO automatic computer, Trevor Pearcy, who was in one sense the brains behind its software, and Brian Cooper, who also had a lot to do with the device. That was a great group of research workers to be involved with.
I came back from the US armed with two essential precursors to making transistors: the technologies for purifying germanium and for growing single crystals of germanium. Brian Cooper and I set up a section on transistor physics and devices, in which I was responsible for purifying the materials, making the transistors and trying to develop physical interests in that material, and Brian was responsible for the testing of the transistors and for designing and building devices which would use them. Through that, CSIRO made a very positive contribution to industry in Australia.
We started off in 1953, very soon after the development of a junction transistor. The course of lectures on it which we gave was attended by about 150 people from a lot of local industry and government instrumentalities such as the then Long Range Weapons Establishment, and we later had visits from individuals from each of four companies in Australia – AWA, STC, Philips Australia and Ducon – who worked with us and absorbed some of the day-to-day problems of working in the transistor field. Brian and I wrote a book based on our lectures (probably the first book about the transistor ever written) which was published in 1953 by the Division’s publications section. Later it became a recommended textbook for the University of New South Wales electrical engineering course but neither of us ever seemed to have the time to write a version of the book for commercial publication to meet the increased demand.
You had an association with Neville Fletcher in CSIRO, didn’t you?
Yes. Neville joined us when the section had been going about three years, and made a number of contributions to transistor physics. He had had a very distinguished career at Harvard and had been working for a transistor company in Waltham, where he had established the major guiding principle in power transistor design.
You went to Bell Laboratories again in 1958.
Yes. I was awarded a Commonwealth Fund Fellowship – they were called Harkness Fellowships for a long while afterwards until, unfortunately, they were discontinued – which gave me a great opportunity to work in a group of distinguished scientists, many of them in the semiconductor area. Bell Labs at that stage had 15,000 people, about 5,000 being research workers of roughly PhD or equivalent level. I joined the group of 150 who were in really basic research, at Murray Hill. I did some experimental work on hot electrons in silicon, trying to measure their temperature from the distribution in wavelength of the light emitted by these hot electrons.
By that stage Shockley had left the lab and Bardeen had gone off to the University of Illinois, I think, and was on the way to winning his second Nobel Prize, in superconductivity; but Walter Brattain was still there, a great guy. I had a lot of contact with him, but perhaps most with Dick Haynes. The Shockley-Haynes experiment was the basic indicator of the way in which one injects non-equilibrium carriers into semiconductors – in order, in those days, to get bipolar transistor action going. The Shockley-Haynes demonstration, that one could put a bunch of carriers into a semiconductor and move that bunch around with electric fields, was really the background to the whole of transistor physics at that stage.
Your work connected with early zone refining, didn’t it?
Yes. On my first visit I had heard quite a bit about zone refining. The principle is that you take an ingot or bar of the material to be purified, melt not the whole lot but just a zone of it, and then move that zone along the bar. As it moves along, it collects impurities and deposits them all up at the last end to solidify, except for impurities which have a distribution coefficient the other way, and finish up at the first end. Either way, you end up with pure material in the middle. In germanium in that stage, the purity levels were one part in 109 or better. That was about three orders of magnitude better than any impurity levels previously considered.
Earlier on you had shown, however, that there is an ultimate distribution beyond which you can’t go.
That was an interesting story. In the United States there was quite a lot of discussion among metallurgists and others that there was no ultimate distribution, that the thing would oscillate backwards and forwards. When Bill Pfann spoke to the paper on that distribution which I gave in the United States, he said that poor old Davies, out in Australia, hadn’t heard that news so he simply went ahead and developed the theory of this ultimate distribution. I have always been quite proud of it because it used quite complex mathematical functions called confluent hypergeometric functions, which I haven’t personally seen applied elsewhere in physics.
Am I right in thinking you proved experimentally the correctness of this theory?
Yes. By artificially doping an ingot with gallium, an element which had a fairly high distribution coefficient, one could actually put the ultimate distribution into the ingot by giving it something like 10 or 20 passes and then measure the content of gallium electrically over about four orders of magnitude, and it was to my mind in remarkably good agreement with experiment. There was another aspect of it that I didn’t ever publish. The same distribution applies to the height of an ingot, because germanium expands when it freezes and the expansion or the level of the ingot follows the same rule. And sure enough, if you look at an ingot you will see a distribution of height at the end of it which follows very closely the theoretical distribution of the impurity as well.
In the next career change you went to AWA, with responsibility for much of their scientific activity. Could you say a bit about that?
When I came back to CSIRO from the Commonwealth Fund Fellowship I spent some time writing up the results of the Bell Labs experimental work. Then pressure came from Taffy Bowen to think about leaving the Division of Radiophysics because he would really like someone in my position to work on developing low-noise receivers for the giant radiotelescope which was about to be constructed at Parkes. Sir Lionel Hooke, the Chairman of AWA, had been exerting pressure on me for a couple of years to work in AWA, so in about 1960 I decided to make the switch. That worked out very well.
I became Chief Physicist, with a lab in the same building as the Amalgamated Wireless Valve Co. They made quite a wide range of receiving valve types, principally for the commercial radio and television products of AWA, as well as picture tubes and also power valves for transmitters – television transmitters and the like – which continued a long tradition of excellence that had pervaded the valve company. For example, during the war they made magnetrons, and I believe that at Ashfield they made the only L-band magnetrons anywhere in the world.
Sir Lionel had said, ‘Please do some research in semiconductors.’ The valve company had just begun making transistors locally in Rydalmere, Sydney. At first they brought in most of the components but ultimately they made all their own, encapsulated them and then developed all the reliability aspects that one needed to take full advantage of the much improved reliability of semiconductor devices over valves.
Did they do their own purifications of the materials?
No, they didn’t ever get as far back as making their own crystals. From our work at CSIRO I knew how to do it, so we were able to make an informed decision not to do it. If you do everything yourself, very often you end up becoming commercially unattractive and losing money.
Then you became Chief Scientist of AWA. What were your responsibilities?
I took on the responsibilities of the AWA Research Laboratory, which had a very long and honourable history, about six months after the death of the previous Chief Scientist, Jim Rudd. Also, AWA set up AWA Microelectronics, first as an adjunct to the valve company and then in its own right. That group made the first integrated circuits in Australia (before I became general manager of it) and together with Nucleonics or Telectronics it put together the first implantable cardiac pacemakers to have integrated circuits in them and consequently were highly reliable. I don’t think they lost a single patient because of an electronic device failure in any of the many devices which they made, over many years.
The research lab continued to be responsible for the semiconductor physics work which I had brought with me and for the optical fibre work which by then had started in the company, but it also did quite a lot of work in electronics, telecommunications and defence communications. Optical fibre became a substantial part of the work. We started with hollow optical fibres filled up with dry-cleaning fluid – saturated hydrocarbons – which Graeme Ogilvie, a scientist in the CSIRO Tribophysics Division, had worked out would not absorb much light. So, if one made hollow tubes – kilometres long, taking a long while to fill from one end with liquid – those fibres would be of considerably lower transmission loss than the current versions of optical fibres with their solid cores. We made an experimental telecommunications system in Australia, setting it up at the Australian National University in Canberra because of the laws relating to access to communication in the public domain across roadways and so forth. We rapidly learnt one important aspect of liquid-filled optical fibres: unless both ends are at the same height, the liquid fairly rapidly drains out – in spite of the difficulty of getting it in there! Anyway, that was in a sense a minor exercise.
We then got into the business of developing and making optical fibres with solid cores. Being the only facility in Australia which could do it, we did quite a lot of defence and general commercial work. Perhaps one mistake was that as a company we didn’t move into cabling the optical fibres. No-one who was in telecommunications really wanted to buy fibres, they wanted to buy cables containing fibres. Ultimately AWA, Metal Manufactures and an American company, Corning, formed a company called Optical Wave Guides (Australia). Later, when I was a director of AWA, we sold our interests in that – primarily the equipment and know-how that we had developed in the lab – for about $13 million. That made me feel quite comfortable with the previous work of the laboratory.
You have a very long list of patents, perhaps even as many as your original papers. Several patents are to do with surface acoustic wave developments. Would you like to talk about that?
Surface acoustic waves are rather like miniature earthquakes on the surface of piezoelectric crystals. If you take a quartz crystal and at one end put an interdigital structure of electrodes, it is possible to send out waves which go in both directions from the transducer, although you can change the pattern in ways which ensure that most of the wave goes in only one direction. And down the other end of the crystal you can have a detector. In this way it is possible to set up delay lines which have very substantial bandwidths. For a long while there was quite a lot of useful and interesting physics to be done and, because it was a brand-new field, quite a lot of inventive work could be carried out: we didn’t know how the surface of the crystal moved, what was the best form of transducer, how to make filters which worked in the ways that one wanted them to. Unfortunately, surface acoustic waves have lost a lot of their interest because of the advances in digital electronics and because one can now simulate the same performance with a silicon device which one can make much more readily. Silicon chips have as many as a million devices on them these days.
Would you tell us about your work on electrets?
Electrets are permanently polarised dielectrics, an interesting electrostatic version of a magnet. We became involved because of AWA’s interest in devising a better version of the microphone in the telephone than the early carbon-button microphone – invented, perhaps, by Alexander Graham Bell. After working quite a while on that, we discovered that if you anodised aluminium and kept the anodising voltage on it when you removed it from the fluid, you ended up with an electret, with quite astounding voltages. It was possible to make electrets which had the equivalent of about 3,000 volts of biased voltage in them. They made an absolutely wonderful electret microphone.
How long would that potential difference be maintained?
Well, it lasted as long as you didn’t allow any charges in the atmosphere to get near it. When we had large volumes, ours used to decay, I think because of the cosmic radiation generating electron-ion pairs in the nearby atmosphere. Once the volume of the microphone was brought down, they seemed to last for quite acceptable lengths of time. Certainly electret microphones are quite common these days.
We also made electret loudspeakers, which worked very well at high frequencies but not so well at low frequencies, where of course you have to have very large areas. That was an interesting development, basically letting physicists loose to follow their noses in an area – with some constraints. Obviously, if we could develop electret microphones or loudspeakers, they would have been of great interest to AWA.
Which of your patents have been the most durable?
Certainly the electret microphone has endured, but I don’t think that AWA ended up making much money out of the rights it had. AWA’s interest, as I understood it, was to have a portfolio of inventions which it could use in its negotiations with other companies on the exchange of intellectual property. We were certainly encouraged to make sure that any worthwhile idea was sent up to the patent department to be looked at. But I still have a note from our then chief of patents, ‘Herewith a copy of your most recent patent. I was somewhat surprised to receive it and I hope we never have to defend it in court’ – very frank, I thought!
You now have a Chair in the University of New South Wales, and you have had high posts in industry. What are your reflections on the relation between basic science and commercial exploitation?
They go together. In industry, people sometimes lose sight of the fact that they are working on ideas or products or processes which would not have existed if someone, somewhere, had not been let loose to work on what they wanted to. That certainly became clear to me when, under a somewhat informal arrangement between the Vice-Chancellor of the University of New South Wales and Sir Lionel Hooke, I was let off the leash by AWA – or, more accurately, rented out – for two days a week as Professor of Electrical Engineering and head of the Department of Solid-State Electronics in the university. One could work on some things in a fairly fundamental way in AWA, but other things such as solar energy and aspects of surface acoustic wave devices were better left to university research, so in a sense I had the best of both worlds. It was certainly hard work. My wife used to say, ‘He spends three days a week in AWA, two days a week at the university, and weekends alternately.’
You mentioned that Bell Labs had 5000 scientists, of whom 150 were in basic science. Did you feel that sort of balance was appropriate?
It seemed to be appropriate for Bell Labs 40 years ago. It is changing with time. Basic research, particularly in physics, involves more and more expensive equipment which means that more and more funds have got to be provided if that work is to be done, and it is a bigger drain on the provider. Naturally, governments are becoming resistant to the idea of keeping the same level of basic research going as before. In my retired state, for example, I am trying to devise some experimental work which I can do at negligible cost, or very close to it, while living out in the country!
I suppose we should be persuading government to support basic science in Australia.
Sure. Certainly it should not be cut to zero. In Bell Telephone Labs, somewhere around 2 to 3 per cent of the total R&D expenditure – even allowing for the extraordinary expenditure on equipment that would be needed in the applied areas, like new ways of making semiconductor devices or research in developing compound semiconductor transistors such as gallium arsenide – seemed to be quite appropriate to their activities. How that would work out on the Australian scene today I have not really calculated, but I suspect that Australia has spent well above that level in relation to the total government expenditure on research and development. It is the lack of expenditure other than by governments that has made life more difficult for the country to achieve an appropriate level of research, I think.
Lou, you have been interested for a long time in solar energy, in several different connections. Would you like to sketch for us how that has worked out for you?
I guess my first interest in solar energy arose from very early days of direct conversion to electricity using a p-n junction in a semiconductor. I think the first person to do so was Gerald Pearson, who was at Bell Telephone Labs when I was there. Since then there have been a lot of developments in that part of the conversion.
When I was in the AWA research lab I had some ideas on a different form of silicon-metal contact and managed to get a grant from the then Australian Research Grants Committee to do some work in that. It became pretty obvious that I would not be able to get the work done nearly as rapidly at AWA as I could at the University of New South Wales, so the ARGC agreed to the transfer of the grant there. Then Martin Green, in my department, joined me and, so to speak, took off with the baton. He and his colleague were awarded the Australia Prize this year for their outstanding developments in increasing the efficiency of conversion of solar energy to electricity and also because of the vastly deeper insights that they have into what is actually going on in the semiconductor structure when the sunlight hits it.
I also got interested in solar energy generally and other forms of conversion – principally mechanical through heating. I used to give a course of lectures at the university on solar energy conversion, doing quite a bit of work on biological techniques – plant growth, basically, or conversion into firewood, to put it into straightforward technology.
Broadly speaking, do you think the Martin Green approach is the most promising way forward in solar energy?
Well, solar energy has always had niche applications. There are many isolated repeater stations for cross-country microwave transmission and so forth which benefit from photovoltaic cells. But one always has to have storage associated with it for when the sun is not shining, mainly during night or heavy cloud – although even under heavy cloud conditions there is probably 25 to 30 per cent of the energy still falling on the cell. As the price of solar cells comes down, the potential applications for it increase, and they increase still further as the prices of coal and oil go up.
There is in Australia quite an extended range of tidal opportunities, which the French have shown work very well in generating electricity. The problem for us is that it is all up on the north-west coast, around Broome and Derby, where there aren’t any industries to use it. Once a way has been worked out to convert the electricity generated up there into a useful product, like aluminium or some other material that is readily transported, then it may take off. I am never too sure about heat applications, other than solar energy for architectural heating and so on.
Do you mean in capturing the sun’s rays and concentrating them?
Yes. If you are not dealing with direct sunlight but tracking and concentrating, you collect only about 70 per cent of the energy that is falling; the other 30 per cent comes from scatter in the rest of the sky. I think that ultimately, when we run out of stored energy resources like coal and oil, we will have to switch to nuclear generation or solar energy generation.
You have carried your experience into directorships in some commercial activities and also pursued new interests in a change of lifestyle. Could you tell us about those?
After I retired from AWA I was invited back onto the board, retiring as a director (as required under the company’s articles) at the age of 72. I also served on the board of the subsidiary company, Radio 2CH Pty Ltd, which was an interesting time and convinced me very early in the piece that a DPhil in physics has very little to do with running a radio company!
I had earlier been appointed to the board of Ludowici, a public company that has been around for 150 years or thereabouts. It once was in the business of making leather gloves and blacksmiths’ aprons but is now thinking in a much more high-tech oriented way, so I was invited to provide some technological input. Ludowici is strongly involved in mineral processing, as well as rubber and plastics, and also it has a controlling interest in Hawk Packaging, a New Zealand company which uses very sophisticated engineering techniques to convert waste paper into useful products. You put waste paper in one end of the machine, and apple trays – about 60 million a year – or wine trays or egg cartons come out the other.
In a somewhat different twist, in 1978 you became a grazier.
Yes. There is a subtle distinction on the Australian scene between a grazier and a farmer. As a farmer would say, a grazier sits on the front verandah, watches his cattle or sheep, as the case may be, going past and notes the new arrivals as they arrive. My wife and I certainly don’t have a tractor and we don’t farm. We breed beef cattle, which we can still cope with on foot, with a bit of input from our elder son and his family, who live fairly close by. It is an activity which gives you a lot of fun and there is always something to do. And, as a general rule, it doesn’t matter terribly if it doesn’t get done today!
But you have some soil physics on the side.
That’s correct. Firstly, I happened to get myself appointed to a committee of the Environmental Protection Agency in New South Wales, which was looking at the hazards that might ensue if one were to spread sewage sludge on or under the ground – or put it on the ground and then plough it in, which would be of no interest to anyone running pastures and a grazing facility. The experiment on our place was to inject sewage sludge under about 15 hectares of our pastures for three years, during which a researcher from the Department of Agriculture took kidney fat samples from our stock (slaughtered nearby).
Would they have been looking for residues of heavy metals, such as cadmium, from the sewage sludge?
Yes. Copper and zinc are the two major ones, owing to the plumbing that most of the sewage runs through. Zinc in particular can’t be allowed to rise to very high levels. The other concerns are principally pathogens like tapeworm eggs and some hydrocarbons, such as from tins of Dieldrin and so on which some people tip down the sewerage system. That can be disastrous.
The venture worked out well. In addition, I have some mad ideas, I suppose, on ways of coping with soil acidity other than the current ones, which are basically spreading lime and making use of its neutralising properties.
Your activities have included being partly instrumental in establishing the Academy of Technological Sciences. How did that come about?
The Australian Industrial Research Group, a group of research directors in Australian companies which still meets quarterly, decided that there should be some organisation like the Australian Academy of Science which would provide an incentive for people to do well in the applied sciences and engineering. The originator of the idea, Alan Butement, who was then with Plessey, and five others – Bill Whitton, Bob Ward from BHP, Keith Farrer from Kraft, myself and Howard Warner – had quite a number of discussions with the Academy of Science but ultimately it became evident that there was very little prospect of the Academy admitting applied scientists and engineers in any large numbers.
So we moved to set up the Academy of Technological Sciences – and Engineering, as it later came to be known. The Chairman was Sir Ian McLennan, who did a wonderful job in steering everyone towards getting the organisation up and running. It has made a number of useful contributions over the years, assessing a lot of topics and giving advice to the government. I was on the committees for two useful reports which it generated: the Espie committee on high finance basically led to the establishment of the management investment company set-up in this country, and the Madigan committee on space science – like another space science committee I was on – produced some wonderful recommendations, most of which were accepted except those relating to the finance. Consequently nothing really ever came of them.
You have received many honours. In particular, my attention was attracted to your Fellowship at the Institute of Electrical and Electronics Engineers, based in New York. What would you say motivated them to elect you?
Well, it arose because for many years I had been a senior member of the Institute, which is not just a United States organisation but extends worldwide. It makes a very valuable contribution by publishing widely in the whole field of electronics and power engineering. Professor Brian Anderson, who is currently President of the Australian Academy of Science, asked whether I would consent to having my name put up for the contributions I had made in zone refining of semiconductors for transistor manufacture, for the work I had done on plasmas in semiconductors, and also to some extent, I guess, for some way-out experiments we had done in my lab in AWA. And so, surprisingly, I found myself elected a Fellow of the Institute.
Would those contributions have included your work on electronic heating in metals?
I suppose so. We were looking at hot electrons in metals, which one could basically make a cold cathode from. Normally one has to heat the cathode in a valve and it emits electrons. If you could heat the electrons only, rather than the metal, that would lead to increased life, overcoming one of the principal stumbling-blocks for valve engineering – or tube engineering, as the Americans would call it.
In a career of such unusual variety and distinction, what has given you the most personal satisfaction?
The first thing was the work on zone refining, arriving at the ultimate distribution – mainly because everyone else thought it was impossible. By applying appropriate mathematical techniques which I had been taught at school and at the University of Sydney, however, I was able to surmount it. I was reasonably pleased too about my work on electron-hole plasmas in semiconductors, because not too many people had worked on that area before, and on electrets, which till then had been for the most part neglected in device physics or in finding practical uses for this physical phenomenon.
Then there have been contributions which are ongoing through the work of others. Our CSIRO lab was the first to get moving in the transistor field, by which we certainly provided a useful service to industry. AWA was the first in the optical fibre area, as far as both fabrication and optical fibre telecommunications were concerned. Now called photonics, that has become the new growth area of electronics and telecommunications.
Last but not least are the PhD students I had working with me – I hesitate to say that I ‘trained’ them because I think I learnt more from them than they learnt from me. Some have had very distinguished careers. Sitthichai Pookaiyaudom, for example, a Thai student whom I first encountered in the third year of his undergraduate course, did a PhD on surface acoustic wave devices. He then went back to Bangkok and started his own electronics company and later his own university. He is now the President of the Mahanakorn University of Technology, which I understand has about 12,000 engineering students, mostly electrical engineers. The last time I spoke to him he surprised me by saying, ‘We’ve just launched a satellite – but only a small one.’ Apparently it has been designed and put together with components from the Radio Shack (a relatively cheap source of electronic components in the United States) and then launched as an add-on to someone else’s large satellite. His students then have the tremendous opportunity to track the satellite as it is going over, using their own frequencies and their own technologies.
Lou, may I say how much I have enjoyed this conversation with you about your outstanding career. Thank you very much.
Well, it is very kind of you. I have enjoyed trying to put thoughts together and answering some of the difficult questions you have asked me. It seems to me it all happened a long while ago.
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