Cashman thallous sulfide cell.
Although Robert J. Cashman was not the first to make reliable photoconductive cells of thallous sulfide, his wartime investigations are of historical significance. From these efforts, he learned a technique to photosensitive lead sulfide. This permitted infrared systems to be built with considerably improved response to thermal emissions, and interest in infrared technology rapidly grew. Cashman's work was sponsored by OSRD during the war years 1941-1945. His efforts were directed toward perfecting a usable cell and were undertaken by empirically noting the effects obtained by varying the parameters associated with constructing a cell.
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