Effect of copper concentration on the physical properties of ZnS:Cu alloys prepared by chemical bath deposition

Abstract

ZnS:Cu thin films were deposited on glass substrates by chemical bath deposition technique. The structural, morphological, optical and electrical properties of the grown films were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectrometry, scanning electron microscopy, spectrophotometry, spectrofluorimetry and Hall effect measurements. Both XRD and Raman analysis indicated the coexistence of both sphalerite ZnS and covellite CuS with cubic and hexagonal structures, respectively. The optical band gap of the films increased from 3.70 to 3.75 eV with Cu concentration increment. Photoluminescence studies revealed that the incorporation of Cu 2? ions in ZnS matrix blue shifted and quenched the emission bands. Electric resistivity, volume carrier concentration, surface carrier concentration and Hall mobility were determined from Hall effect measurements. Indeed, for pure sample, the obtained values were about 7.586 9 10 4 X cm, 1.472 9 10 11 cm -3 , 2.944 9 10 6 cm -2 and 5.590 9 10 2 cm 2 V -1 s -1 , respectively. However, after Cu incorporation, these values varied in the range of (2.273 9 10 4 -13.80 9 10 4 ) X cm, (2.334 9 10 11 -9.094 9 10 13 ) cm -3 , (4.668 9 10 6 -1.819 9 10 9 ) cm -2 and (3.092 9 10 -1 -1.937 9 10 2 ) cm 2 V -1 s -1 , respectively.

Spectroscopic investigation of CuxMg0.2−xZn0.8S (x = 0, 0.05, 0.10, 0.15) thin films for deep and dilute blue LED applications

“…With Cu dopant, wurtzite phase contribution is seen to increase. [ 28 ] However, when Mg and Cu are used as dopants, possible good results are obtained if the host has a zinc blende structure. [ 29 ] In other words, at a higher dopant concentration, film growth could be non‐oriented, yielding poor crystallinity.…”

A review of novel methods to improve the optical and electrical properties of n-type and p-type sulphides and oxides: leading the frontiers of semiconductor technology

“…To improve their electrical and optical properties, researchers have explored various strategies, including optimizing the synthesis conditions and doping with impurities such as zinc or cadmium. For example [140], reported that zinc-doped CuS films exhibited a higher electrical conductivity and lower resistivity compared to undoped CuS films. Optimizing the annealing temperature and time can lead to significant improvements in the structural and optical properties of CuS films [120].…”