Mechanistic exploration of charge transport and photosensitivity of metal/polymer/semiconductor (MPS) junction for sensitive light detection applications

Abstract

Herein, PVA: PVP@Ni(OAc)2 nanocomposite spin-coated thin films have been fabricated as a barrier modifier interlayer in a metal/polymer/semiconductor configuration for light detection applications. The nanostructure, as well as the surface roughness profile of the deposited thin films, have been inspected using a high-resolution transmission electron microscope (HR-TEM) and field emission scan electron microscope (FE-SEM). The obtained results showed nanoplatelet architecture films with smooth surfaces of average roughness of ~ 7.08 nm. The optical absorption, reflection, and transmission spectra have been analyzed and the value of the fabricated film’s energy gap has been confirmed with several analytical approaches. Furthermore, the DC electrical properties of Ag/Si (n-type and p-type), as well as Ag/polymer nanocomposite/Si (n-type and p-type), have been investigated under dark conditions. The microelectronic properties have been estimated using thermionic emission, Norde’s, and Cheung-Cheung’s models. Besides, the mechanistic details of charge transport have been explored under forward and reverse bias conditions. The photoresponsive features of the designed Ag/ PVA/PVP@Ni(OAc)2 /p-Si junction have been evaluated under different illumination intensities. The current device achieved superior photodetection capability with high responsivity, detectivity, and fast switching behavior.