Based on photoconductive and photovoltaic effects of Semiconductors, a variety of infrared detectors such as InSb, GeAu and HgCdTe have been developed and widely used in industrial application, medical examination, weather observation and pollution measurement. To extend spectrum ranges, we are now studying infrared detectors using new materials such as PbSnTe.
In this paper, we have reported the outlines of InSb, GeAu and HgCdTe infrared dete-ctors. The problems of the detectors may be summarized into five points, including (1) detector housing, (2) detector element sensitivity, (3) time constant, (4) cooling of element and (5) spectral response.
Binary semiconductors, Hg1-xCdxTe and Pb1-xSnxTe, have composition-dependent energy gaps which can be made arbitrarily small according to the proposed band model, The unique structure of the energy bands together with the ease in producing single crystals of excellent homogeneity and good quality have made these alloys particularly useful for long wavelength infrared detectors as well as lasers.
As described above, HgCdTe and PbSnTe crystals provide very interesting characteristics and are the most suitable materials for infrared detectors. A great many applications of HgCdTe and PbSnTe detectors may be expected in the near future.
