Photo Sensing Properties of Porous Silicon (PS): p-Si and ZnO-PS: p-Si -MSM Devices: A Comparative Analysis

Present study reports fabrication and photo sensing property of metal-semiconductor-metal (MSM) devices based on Al/PS: p-Si and Al+Au/ZnO-PS:p-Si heterostructures. FESEM analysis confirms growth of spherical shaped nanostructured ZnO layer of thickness similar to 160 nm on similar to 370 nm thick PS: p-Si structure. Dark current analysis of the heterostructures gives ideality factor (n) of 7.1 and 4.36 respectively. Electrical properties explored for heterostructures under illumination condition (250-500 nm) reveal superiority of ZnO-PS:p-Si heterostructure in terms of high responsivity similar to 2.6AW(-1), high EQE similar to 800% and response time of 0.3 sec compared to similar to 0.3AW(-1), similar to 85% and 0.15 sec respectively for PS: p-Si heterostructure.