Tin Disulfide Lab Report

Influence of precursor solution volume on the properties of tin disulfide (SnS2) thin films by nebulized spray pyrolysis technique.

N.Anitha, M.Anitha, L.Amalraj*

Research department of Physicis, V.H.N.S.N College (Autonomous), Virudhunagar-626001. [e-mail]

Abstract

In this work, golden yellow colored thin films of tin disulfide (SnS2) have been deposited by nebulized spray pyrolysis technique on a glass substrate at 250ºC. The influence of precursor solution volume (5-25 ml) on the crystal structure, optical, surface morphology and electrical properties was determined by X-ray diffraction, UV spectroscopy, SEM analysis and four-probe points. The X-ray diffraction studies revealed polycrystalline nature having a hexagonal structure

Semiconducting metal chalcogenides are used as polarizers, sensors and thermoelectric cooling materials [1]. Among many semiconducting metal chalcogenides, tin sulfides have fascinated extensive interest due to its photoconductivity properties for photo voltaic energy conversion. Tin sulfide exists in a multiplicity of phases such as SnS, SnS2, Sn2S3 and Sn3S4 due to bonding characteristics of tin and sulfur [2]. The Tin disulfide is an n-type semiconductor with hexagonal CdI2 structure. It is composed of one tin atom sheets sandwiched between two close-packed sulfur atoms sheets [3]. Polycrystalline films and single crystals of SnS2 have shown optical band gaps in the range of 0.8 – 2.88 eV [4-7]. It has a high optical absorption co-efficient in the visible region (>104 cm-1) [8, 9, 10]. Although the SnS2 thin films can be prepared using various methods such as Spray pyrolysis [11- 14], chemical vapor deposition [15], dip deposition [16, 17], chemical deposition [18], salvo thermal synthesis [19], Successive ionic layer adsorption and reaction [20, 21], double - source reactive evaporation [22, 23], sulphurization of metallic precursors [24], vacuum thermal evaporation [25], ultrasonic spray [26, 27] and vacuum evaporation using a SnS2 tablet as a source with a special boat-type heater [28], close spaced

The scanning angle 2θ was varied in the range of 10-80 in steps of 0.05º. The optical absorption spectrum of these thin films was recorded in the wavelength range 300 to 1100 nm using Shimadzu-UV 1800 model double beam spectrophotometer The room temperature electrical resistivity, hall co-efficient, mobility and carrier concentration were measured using an automated Hall Effect system (ECOPIA HMS – 3000). The surface morphology of the SnS2 thin films was examined by CARLZEISS (EVO18) scanning electron microscope with a magnification of ------------. The chemical composition of Tin and Sulfur was determined by energy dispersive analysis by X-rays (EDAX) on K and L lines using BRUKER (XFLASH X130)