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The 2009 Kyoto Prize
2009
11 /11 Wed
Place：Kyoto International Conference Center
The 2009 Kyoto Prize Kyoto Prize Laureates
Lecture topics
Enchanted Journeys in Blue Light
Abstract of the lecture
I gained an interest in luminescence when I was assigned to a group working on the fluorescent screens of Braun tubes for televisions at my first job after university. Then, I was involved in research work at Nagoya University on single crystal growth of germanium (Ge) and physical properties of Ge and several other semiconductors. In 1961, I succeeded in growing a Ge single crystal film by what is now known as the “vapor-phase epitaxial growth method.” This achievement led me to a position at the then newly-established Matsushita Research Institute Tokyo, Inc. in 1964, where I began my research on crystal growth and light-emitting devices of III-V compound semiconductors. In the 1960s, red and yellow-green light-emitting diodes (LEDs) and infrared semiconductor laser had already been realized, but there was no prospect for practical blue light-emitting devices even in the 1970s. Both of the two essential requirements for creating high-performance blue light-emitting devices, namely, the growth of high-quality single crystals of semiconductors with wide bandgap energy, such as gallium nitride (GaN), and realization of their p-n junction, were extremely difficult to achieve. I set for myself the goal of overcoming these difficulties in some way so that I could develop GaN p-n junction blue light-emitting devices. As expected, the task of crystal growth was tremendously difficult, and I was forced to go through a continuous process of trial and error. By the late 1970s, many researchers had withdrawn from studies on this “unexplored semiconductor,” but day in and day out I continued my research of GaN crystal growth simple-mindedly, feeling as if I was “exploring the wilderness alone.” Then in 1978, I successfully caught a glimpse of tiny yet high-quality crystals through my microscope, when I sensed the potential of GaN. And again, I decided to go back to the basics, i.e., “crystal growth.” In retrospect, this was a major turning point both in my research and in the R&D history of GaN in general. In 1979, I chose to adopt “metalorganic vapor-phase epitaxy (MOVPE)” which I believed to be the optimal crystal growth method for GaN. The correctness of my own choice has been attested by the fact that even today this method is almost invariably chosen to fabricate GaN-based devices, including blue LEDs. Since 1981, with the most generous cooperation of graduate students and co-researchers at Nagoya University, I achieved a series of “firsts” in the world, including high-quality GaN using the low-temperature buffer layer technology, p-type conduction by electron beam irradiation of high-quality GaN doped with magnesium, and GaN p-n junction blue LEDs. In my lecture, I would like to speak more about the subsequent developments of my research.
Lecture topics
In Charles Darwin's Footsteps
Abstract of the lecture
Charles Darwin visited the Galápagos archipelago for five weeks in 1835. His observations on animals, plants and volcanoes contributed to the development of his revolutionary ideas about evolution by natural selection. Finches, now known as Darwin's finches, were an important element in his thinking. We have been visiting Galápagos every year for the last 37 years in order to understand in detail how the ancestral species of finch, arriving in the archipelago two to three million years ago, gave rise to the 13 species of Darwin's finches living there today. Each of us grew up in England and experienced nature in the countryside. We received our undergraduate training in Britain, then migrated to the University of British Columbia where we met. Many years later, after we had married, obtained a job at McGill University in Canada, and started a family, we launched a program of field research on the Galápagos islands. Our previous training had been different: Peter had specialized in ecology and Rosemary had specialized in genetics. These separate fields of expertise enabled our joint research to be more than the sum of the parts. The interaction between our different ways of thinking about problems gave us greater insights than either of us would have reached alone by staying within our own respective fields. The research was initially designed to address three questions. First, how do new species form? Second, has competition between species been important in their evolution? Third, why do some populations vary much more than others in characteristics such as beak or body size? To answer them we combined a study of different finch communities on several islands in the archipelago with a study in great detail on the islands of Genovesa for 11 years and Daphne Major for 37 years: patterns in space combined with processes in time. Our most important finding has been that evolution by natural selection can be observed, measured and interpreted, and it occurs repeatedly when the environment changes. Darwin would have been surprised, since he believed that evolution occurred too slowly for anyone to see, but would have been delighted.
Lecture topics
In Charles Darwin's Footsteps
Abstract of the lecture
Charles Darwin visited the Galápagos archipelago for five weeks in 1835. His observations on animals, plants and volcanoes contributed to the development of his revolutionary ideas about evolution by natural selection. Finches, now known as Darwin's finches, were an important element in his thinking. We have been visiting Galápagos every year for the last 37 years in order to understand in detail how the ancestral species of finch, arriving in the archipelago two to three million years ago, gave rise to the 13 species of Darwin's finches living there today. Each of us grew up in England and experienced nature in the countryside. We received our undergraduate training in Britain, then migrated to the University of British Columbia where we met. Many years later, after we had married, obtained a job at McGill University in Canada, and started a family, we launched a program of field research on the Galápagos islands. Our previous training had been different: Peter had specialized in ecology and Rosemary had specialized in genetics. These separate fields of expertise enabled our joint research to be more than the sum of the parts. The interaction between our different ways of thinking about problems gave us greater insights than either of us would have reached alone by staying within our own respective fields. The research was initially designed to address three questions. First, how do new species form? Second, has competition between species been important in their evolution? Third, why do some populations vary much more than others in characteristics such as beak or body size? To answer them we combined a study of different finch communities on several islands in the archipelago with a study in great detail on the islands of Genovesa for 11 years and Daphne Major for 37 years: patterns in space combined with processes in time. Our most important finding has been that evolution by natural selection can be observed, measured and interpreted, and it occurs repeatedly when the environment changes. Darwin would have been surprised, since he believed that evolution occurred too slowly for anyone to see, but would have been delighted.
Lecture topics
Labyrinth of Ideals
Abstract of the lecture
The poet Stéphane Mallarmé, in response to a question put to him towards the end of his life about the ideals of youth, wrote: "Whether happy or in vain, the will I had in my youth has remained intact." I have begun with what I should probably have finished with, since if it is already difficult to sum up a life, it is impossible to foresee it or direct it as one wishes. However, it is possible to say that self-discovery takes place at the same time as self-formation. Ideals, strictly speaking, emerge from the more or less hazardous encounters, to which you react intentionally while repeating the process of accepting one thing and rejecting another. Having instinctively grasped modernity, I wished to make it accessible to myself, to master it and understand it. At the same time, I was fully aware that I was not equipped with the tools to do so; that is, I had no mastery of language, grammar or style. So I definitely had to begin at this learning stage. This necessity for learning has resulted in a line of action for me which was initially rigid but has gradually become flexible. All this has, of course, happened through an indispensable given material: sound, and at a time of confrontation between traditional materials and resources expanded by electronics. Questions continue to emerge, and to find autonomous answers to them, it is necessary to embrace a strong ideal. Can this ideal be expressed in exact words? Impossible. It is really impossible to answer. If you knew the answer, how could you then write or produce anything? Anyway, my motivation is the unknown that is inside of me and that cannot be known exactly until it is given shape. The path of ideals is thus constructed by successive provisional steps. I would like to close by citing once again Mallarmé's response to the question about ideals of youth: "I was faithful enough to myself to ensure that my humble life has maintained a meaning." I would like to add that "humble" is not just a word, but it is a very realistic observation, considering the difficulty and scale of the project undertaken.
