COMPARISON OF SCHOTTKY-BARRIER AND DIFFUSED JUNCTION INFRARED DETECTORS

The resistance-area product (RoA) of Schottky barrier and n-p diffused junction infrared detectors of PbSnTe, PbSnSe and HgCdTe under conditions of zero bias have been calculated over the temperature range of 50-200 K. The calculations are restricted to carrier concentrations in which Auger band-to-band recombination mechanism is predominant. A comparison of the detectivities, D,′ and the depletion layer capacitance per unit area, (C/A), of various diodes has been made at 77K. The results indicate that even though n-p diffused PbSnTe and PbSnSe photodiodes have higher detectivities, their Schottky barrier diodes too have detectivities more than 1011 Cm Hz 1 2/W. The calculated value of the detectivity of HgCdTe Schottky barrier photodiode, however, turns out to be an order less. © 1979.