Anomalous Non-Equilibrium State Response of Long-Wavelength HgCdTe Infrared Detectors

Nowadays, long-wavelength infrared (LWIR) HgCdTe infrared detectors are developing towards high operating temperatures. There remains a lack of knowledge on the operational mechanism of LWIR HgCdTe at room temperature. This letter conducted an in-depth study on the anomalous non-equilibrium state of LWIR HgCdTe at room temperature. Through laser beam-induced current (LBIC) photocurrent mapping testing, it was found that there are high-energy non-equilibrium states. The junction formed by non-equilibrium states has a minority carrier diffusion length of up to $30 ~\mu \text{m}$ through LBIC line profile formula fitting and a carrier lifetime of up to 45 ns through time-resolved photoluminescence. It indicated that high-energy photons can excite electrons in LWIR HgCdTe to transition to a stable high-energy state and participate in the carrier transport process.