Hg_3In_2Te_6-based radiation and temperature stable photodetectors

摘要

The Cr/Hg_3In_2Te6/Cr surface-barrier structures, photosensitive in the range of 0.5-1.8 μm, have been studied by optical, electrical and photoelectric measurements. The remarkable feature of the created diodes was using the same metal (Cr) to form both Ohmic and rectifying contacts employing different surface treatments of the corresponding semiconductor faces. This simplified the fabrication technology and increased radiation resistance of the photodetectors. Dark (leakage) currents of the photodiodes at reverse bias of 10 V did not exceed 3-5 μA for the photosensitive contact area of 1 mm~2. The monochromatic current sensitivity was 1.1-1.2 A/W at the spectrum maximum (1.57 μm) and such photodetectors showed high temperature stability. In the range from -40 °C to +40 °C, the sensitivity at the maximum varied within 10-15% that corresponded to the temperature coefficient of photosensitivity (TCP)~ 0.2% per degree. From -10 °C to +20 °C, TCP was < 0.05% per degree. Thermoelectric cooling can significantly improve the photodetector characteristics.