Photo-enhanced native oxidation process for Hg0.8Cd0.2Te photoconductors

The aim of this paper is to propose an easy and reproducible vapor-phase ph oto surface treatment method to improve the device performance of the Hg0.8 Cd0.2Te photoconductive detector. We explore the effect of surface passivat ion on the electrical and optical properties of the HgCdTe photoconductor, Experimental results, including surface mobility, surface carrier concentra tion, metal-insulator-semiconductor leakage current, 1/f noise voltage spec trum, the 1/f knee frequency, responsivity R-lambda, and specific detectivi ty D* for stacked photo surface treatment and ZnS or CdTe passivation layer s are presented. These data are all directly related to the quality of the interface between the passivation layer and the HgCdTe substrate. We found that, by inserting a photo native oxide layer, we can shift the 1/f knee fr equency, reduce the noise power spectrum, and achieve a lower surface recom bination velocity S, A higher D* can also be achieved. It was also found th at HgCdTe photoconductors passivated with stacked layers show improved inte rface properties compared to the photoconductors passivated only with a sin gle ZnS or CdTe layer.