Current Transport and Capacitance–Voltage Characteristics of the Novel Al/n-Si/CuGaSnS4/Au Heterojunction

This research work introduces the growth of CuGaSnS4/n-Si heterojunction using a spray pyrolysis procedure on a pre-washed n-type silicon substrate. The X-ray diffraction (XRD) investigations presented an orthorhombic single phase of the CuGaSnS4 thin films. The surface morphologies of CuGaSnS4 samples were fixed via the field emission scanning electron microscope, FE-SEM which depicted a homogeneous surface for the investigated films and the EDAX pattern of CuGaSnS4 films confirms the presence of copper, gallium, tin and sulfur atoms with an atomic ratio near to 1:1:1:4. The dark current–voltage investigations were hired to estimate the heterojunction parameters like the diode ideality factor values (n), shunt resistance values (Rsh) and the effective barrier height (ϕb\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\phi }_{b}$$\end{document}). The studied heterojunction revealed good rectifying behavior through the dark current–voltage curves. Also, capacitance–voltage investigations in dark conditions were used to evaluate the built-in voltages and the net carrier concentration. Many interesting photovoltaic parameters have been estimated for the studied heterojunction such as the solar efficiency (η), the fill factor (FF) and open-circuit voltage (VOC). Moreover, the solar efficiency (η) of the CuGaSnS4/n-Si heterojunction has been inspected using current–voltage measurements under illumination and we found that the CuGaSnS4/n-Si heterojunction revealed solar efficiency equal 1.52%.