Marked Effects Of Al-Rich Aln Transition Layers On The Performance Of Cdznte Films For Solar-Blind Photodetector

Al-rich AlN transition layers (AlN-Al) on AlN ceramic substrates (c-AlN) are as pioneering work to prepare high quality CdZnTe films. It is pronounced that the structural and electric properties of CdZnTe films based on AlN-Al are enhanced. Among all the CdZnTe films, steepest diminishment of dislocation density can be by 78.84% on the surface and maximal drop is more than quadruple for Cd vacancy on the interface, compared with no Al-rich ones. Subjected to investigation of Al on the interface by EDX and low temperature PL, AlN-Al have provided Al3+ to compensate defects in CdZnTe films, and the diffusion process of Al3+ is discussed. The amount of Al3+ at the interface of CdZnTe is on a tendency of proliferation preceding recession and the optimum is where doping content of Al in transition layers is 1 wt %. The optimal photo-dark current ratio and responsivity of CdZnTe/AlN-Al/c-AlN composites with parallel electrodes under 254 nm UV light illumination are around 369 and 10.6 mA/W, indicating a brilliant prospect of detection in solar-blind region.