Fabrication and photoresponsive characteristics of ZnO film for ultraviolet ZnO/porous Si photodetector: The effect of post-processing treatment

Abstract

This article demonstrates a well-designed fabrication process of ultraviolet (UV) ZnO/porous Si photodetector as a function of post-processing temperature. The structural and optical features of the deposited ZnO layers were thoroughly elucidated through which a robust correlation between the post-processing temperature and the addressed characteristics were established. Particularly, a decrease in the attained energy bandgap from 3.3 eV to 3.22 eV was obtained upon increasing the treatment temperature from 600 °C to 800 °C; the morphological analysis revealed the occurrence of average nanoparticle diameters of 69 nm and 64 nm, respectively. Continuously, the fabricated devices also demonstrated a well-established relation with the applied post-processing temperature wherein relatively high photoresponsivity and specific detectivity were attained at high temperature. Specifically, the photoresponsivity and specific detectivity values were observed to be 5.6 (μA/mW) and 1.8×1011 Jones at 25mW/cm2 illumination power using treatment temperature of 800 °C, respectively. In the meanwhile, the response time of the proposed device was estimated to be ∼300ms.