20) Initiator of the boom of amorphous semiconductors
Picture: Mr. and Mrs. Ovshinsky interviewed in 1969
In early spring 1969, I received phone call from the person
called Stanford Ovshinsky. I intuitively realized that he is Ovshinsky who
is well known in the research work of amorphous materials. He presented the
paper titled “The reversible switching phenomenon in disordered structure”
in the Journal of American Physical Society published in November 1968. It
caused several arguments how to evaluate this paper.
He said “I want to explain the research result to you. I’m staying in the
Imperial Hotel, so please come to my hotel”. I visited the hotel, and he was
waiting for me with his wife Iris, biochemist. After short greetings, I had
to listen to his very difficult explanation.
His research target was chalcogenide amorphous semiconductors using chalcogen
elements such as Sulphur, Selenium and Tellurium, which were produced by liquid
quenching technique. This material is in the thermodynamically nonequilibrium
state, so the structural change will be caused by the energy of outside heat
and light. He tried to use this material to electric switches, memory devices
and optical materials. When considering amorphous materials are today widely
used, we can say that this is the result of his initiation of amorphous semiconductors
boom.
Ovshinsky was born in Ohio, U.S.A. in 1922. After graduating high school,
he worked as tool manufacturer, mechanical engineer, etc., and then he was
engaged in the research of neuro physiological mechanism of nerve cell synapse,
the development of thin film electrochemical amorphous switch and so on. Then
he founded Energy Conversion Devices together with Iris in 1960. He is prominent
in success story. In 1990, he founded United Solar Systems, joint venture
with Canon and started manufacturing solar cells.