Residual disturbance effect of array HgCdTe detector irradiated by laser

A new phenomenon, known as the residual disturbance effect, was discovered during the experiment of a photovoltaic (PV) array HgCdTe detector irradiated by continuous laser. Specifically, when the laser power reaches a certain value, some pixels still exhibit varying degrees of response after the laser is turned off, and they gradually return to a normal working state as the laser stop time extends. To investigate the potential causes of this phenomenon, models of the readout circuit and the photosensitive chip were established using PSPICE circuit analysis software and COMSOL Multiphysics finite element simulation software, respectively. The mechanism behind this phenomenon was explored by studying and analyzing the discharge time of the capacitor in the readout circuit, the charge carriers in the photosensitive chip, and the change of temperature with illumination time. Research indicated that the displacement defects of Hg atoms in HgCdTe materials at high temperatures could be a possible cause of the residual disturbance effect. Due to the heating effect of a high-power laser, Hg atoms in some pixels are displaced, resulting in displacement defects. This phenomenon will produce relaxation after the laser ceases, leading to partial pixels being unable to function properly without the laser. As the temperature decreases, the material atoms recover after some time, allowing the detector to return to normal operating conditions.