Low temperature readout circuit characteristics of low dimensional compound semiconductor photodetectors

摘要

In this paper we analyze the necessity of design of low temperature readout circuit. Since the photodetector should work in low temperature environment, it is necessary for the readout circuit with low temperature readout function. Meanwhile, the influence factors of ultra - low temperature on the CMOS readout circuit are analyzed. The main influencing factors are carrier freezing analysis, current mutation (Kink) and mobility change. Finally, we used JANIS SHI-4-2 liquid helium cycle refrigeration system as a refrigeration instrument, and do the test for the readout circuit at ultra -low-temperature. When the temperature of cold head of the cooling system reach to the minimum temperature (4.85K) and maintain 5 hours, Si substrate' temperature reaches the minimum temperature (50.1K). By adjusting the static operating point voltage, we find that the circuit still works well.