The dark current mechanism of HgCdTe photovoltaic detector passivated by different structure

The HgCdTe photovoltaic detectors passivated by single ZnS layer and dual (CdTe+ZnS) layers were fabricated in same wafer. The fabricated devices were characterized by measurements of the diode dark I-V characteristics and low-frequency noise. The dual-layer passivated diodes showed the better performance compared to the single layer passivated diodes, and modeling of diode dark current mechanisms indicated that the performance of the diodes passivated by single ZnS were found to be strongly affected by tunneling current related to the surface defects, By the analysis of X-ray reciprocal space maps, It was found the Q_y scan direction broadening of HgCdTe epitaxial layer passivated by ZnS was wider after passivation, which confirmed the existence of defects in the surface of HgCdTe epitaxial layer passivated by ZnS.