Dark current in the HgCdTe infrared photodiodes

The main factor that effects on the performance of the photodiodes is the dark current, which should be small in order to reduce noise and ensure a high level of parameters. To identify the dominant mechanism of generation-recombination in MCT photodiodes in given voltage range, a dark current simulation due to fundamental and other current mechanisms have been proposed. Dependences of the dark current components in the range of reverse bias voltages from 0 to 40 mV have been determined for photodiodes fabricated in heterostructures on the base of cadmium-mercury telluride (CdHgTe) ternary solution grown by molecular beam epitaxy (MBE) and liquid-phase epitaxy (LPE). In the range from 0 to 20 mV reverse voltage bias characteristics are limited by the diffusion component. An increase in the Shockley-Reed-Hall (SHR) generation-recombination current and tunneling through trap levels in the band gap are observed at reverse bias voltage of more than 30 mV. © 2019 Federal Informational-Analytical Center of the Defense Industry. All rights reserved.