Effect of Thickness on Structural, Optical and Sensing Properties of SnS Thin Films Prepared by Ultrasonic Nebulizer Method

Abstract

Thin Film of tin sulfide with different thickness (100, 250, 450, 600 ) nm have been prepared on pre-heated glass substrates up to (430 o C) by Ultrasonic Nebulizer Deposition (UND). The effect of thickness on the structural, optical, and gas sensing properties of films has been investigated. The results of the XRD show that the film which deposited with thickness (100 and 250) nm exhibit only SnS phase with (111) orientation, and with thickness (450 and 600) nm crystallized in the mixed phase SnS and Sn 2 S 3 depending upon the films thickness. Atomic force measurement showed the grain size increase with thickness in the range of (76.08 -105.67 nm). The optical properties of the films have been studied over a wavelength (370-1100) nm. The calculated optical energy band gap values were between 1.3 and 2.4 eV, depending on the film thickness and in which phase crystallized. The effect of thickness and operating temperature on performance of the sensor material has been investigated to choice optimum thickness and temperature for each ethanol and ammonia gases. The films with 600 nm thickness showed high response and excellent sensitivity for ethanol and ammonia gases at low temperature (140,110) o C and high temperature (380,240) o C respectively.