21) Use of amorphous semiconductors to the solar cell
Picture: Kuwano’s house installing amorphous silicon solar cell panels (Provided
by Yukinori Kuwano)
With regards to the domestic technologies of amorphous semiconductors,
Sanyo Electric’s amorphous silicon solar cell attracted the interest. The
central person of the solar cell development was Yukinori Kuwano, actively
worked in the research department and finally became the President of Sanyo
Electric.
He entered Sanyo in 1963, and he was assigned to Central Research Laboratory.
When assigned, he was told “Do whatever you like”, but he didn’t know what
to do, so he started the research of electric discharge, which he experienced
in the university. He at first mixed Silane and Nitrogen in the vacuum reactor
vessel. and made silicon nitride by glow discharge. Actually, this was amorphous
material and it became the main theme of his research life. After that, he
was heavily involved in the research work of amorphous materials, but he could
not get expected result.
When he was about to consider stopping the research, Yamano, General Manager
of Central Research Laboratory, told to him that “From now on, energy era
will start. You are looking this material for electric component use, but
how about looking this as materials for energy applications.” At the same
time, in the library, he read the English researcher’s paper which says “Amorphous
silicon produced by the glow discharge resolution of Silane gas can control
valence electron by adding impurities”. Shocked by this paper, he started
the experiments, but soon after he got the information that RCA group had
successfully developed solar cell by this technology. Knowing this news, Yamano
again told Kuwano that “If RCA get ahead in the development of solar cell,
you must aim to be the first in industrialization of solar cell”. In this
circumstance, new idea of integrated solar cell was created which Sanyo registered
the patent.
Picture is Kuwano’s house installing his own developed amorphous silicon solar
cell panels. It had signboard of “Kuwano solar photovoltaic power plant”.