A Simulation Based Study and Optimization of CdTe/ZnO/ITO Based Device for Self-Powered Photodetector Perspective

In this work, we have studied the effect of the top electrode on the performance of CdTe/ZnO/ITO-based devices for self-powered applications. The device is studied using different top metallic contacts such as Palladium (Pd), Nickel (Ni), Gold (Au), and Platinum (Pt). The performance is analyzed in terms of maximum power generation point, which is 4.98, 6.03, 8.67, and 10.45 mAV/cm² for Pd, Ni, Au, and Pt electrode, respectively. Pt electrode with a work function of 5.64 eV outperforms the other electrodes. The self-powered response of the device is analyzed for varying thickness of ZnO from 200 nm to 600 nm, and the optimum result is achieved at 450 nm. The device is further analyzed for Quantum Efficiency measurement, and the peak is obtained around ~350 nm, which matches the absorption spectra of ZnO. The Quantum efficiency measurement shows the viability of the device to be used as a self-powered photodetector detector covering the wide region from UV-A (320 nm) to Near Infrared (700 nm).