Impact of deposition voltage on the physical properties of rare earth element doped strontium sulphide for optoelectronic application

Abstract

In this study, electrochemical deposition was used to synthesize SrS-doped zirconium materials at a varying voltage of deposition. The  XRD result shows that SrS/Zr has a prominent peak intensity corresponding to 2theta values of 26.45o , 33.86o , 38.01o , and 51.49o . The  crystal lattice is shown by the prominent peak intensity with higher 2theta degree values; the appearance of an unindexed peak is caused  by the substrate utilized for the deposition. SrS surface morphology reveals a Clove-like surface with precipitate visible in the SrS  micrograph; the large grain size on the surface of the substrate exhibits photon absorption but lacks any signs of pinholes. At the  introduction of zirconium as a dopant to the SrS precursor, there was a drastic change in the precursor which is also noticed on the surface micrograph of the analyzed films. The films show a decrease in thickness from 129.14 to 120.09 nm and an increase in film  resistivity from 1.24 x 109 to 1.29 x 109 ohm.m, which further led to a decrease in conductivity from 8.06 x 108 to 7.75 x 108 S/m. The  impact of the deposition voltage on the reflectance reveals that lower voltage will stabilize the reflectance of SrS/Zr which will be useful  for photovoltaic applications. SrS has an energy bandgap of 1.50 eV while SrS/Zr with bandgap energy of 2.00 – 2.50 eV.