ABSTRACT
The direct conversion of sunlight to electricity using solar cells has had an interesting and colorful history. Today, the use of solar cells is finally emerging as an important tool in man’s quest for new sources of energy, particularly now that the negative environmental impact of burning fossil fuel is becoming so apparent. It was not always so. I began working on solar cells at the time of the first oil crisis in 1973. You could say that I was part of the second generation of solar cell researchers. The first generation had invented the practical silicon solar cell and developed it as the standard source for powering earth orbiting satellites. This article presents my personal perspective on the development of PV from 1973 to the present. (For some reason the rather difficult-to-pronounce term “photovoltaics” has taken hold to describe this endeavor. Those in the field usually just call it PV, which rolls nicely off the tongue, at least in its English pronunciation, “pee vee”. So that is the term I will use here.)
2. The Beginnings of Terrestrial PV
Soon after silicon solar cells became established for powering space satellites in the 1960s, some visionary researchers began looking at what would be needed to make it cost effective for use on earth. They found that something like a 200-fold cost reduction would be necessary in order for PV to compete with conventional fossil fuel sources. This was certainly a big challenge. The silicon solar cells used for space were indeed a very expensive way to generate electric power. It is just that they were basically the only way to do it in small space satellites. The conventional
view was that standard silicon solar cells were incapable of the 200-fold reduction needed for earth use. This lead most researches into one of two approaches, thin films or concentrators.
