The Effect of Substrate Temperature on The Structure and Morphologies of PbS Thin Films Deposited by Ultrasonic Spray Pyrolysis

Abstract

In this work, we aimed to deposit PbS thin films at relatively low temperature and therefore thin films were deposited onto preheated glass substrates at 473 K and 523 K by ultrasonically spraying of equimolar aqueous solution of lead acetate and thiourea. The thickness of deposited thin films was determined by spectroscopic ellipsometry (SE) prior to investigate physical properties of deposited PbS films. In order to investigate structural and morphological properties of PbS thin films, x-ray diffraction (XRD) patterns and Atomic Force Microscopy (AFM) images were obtained. Crystal structure, mean crystallite size, lattice parameters, micro-strain of deposited thin films were evaluated by means of XRD patterns and it was seen that deposited PbS thin films were successfully obtained in polycrystalline form with cubic crystal structure. Also lattice parameter of a was calculated as 5.866 Å and 5.870 Å for thin films deposited at 473 K and 523 K, respectively. Additionally, the surface roughness of PbS thin films was determined via AFM images as 5.8 nm and 9.9 nm in non-contact mode. The obtained results confirm that deposition of PbS thin films can be successfully achieved at relatively low temperature.