Abstract
Tin monosulfide (SnS) films are a new generation of absorber layers for thin film heterojunction solar cell. The goal of the present study is the investigation of the role of the solvent on SnS thin films properties. Films were synthesized by ultrasonic spray pyrolysis technique. The used solution is a mixture of SnCl(2 center dot)2H(2)O and thiourea (SC(NH2)(2) precursors prepared with two different solvents: methanol and distilled water. X-ray diffraction (XRD) analysis reveals the SnS orthorhombic polycrystalline phase in different films. Using methanol as solvent leads to Sn2S3 secondary phase formation. While, film prepared with distilled water contains SnS(2 )as secondary phase. Scanning electron microscopy (SEM) observations reveal that films deposited with the methanol are rough with the presence of craters bubbles on the surface due to gas exo-diffusion during film growth. However, the film deposited with distilled water has a smooth, uniform, homogeneous and pinholes free surface. The electrical measurements reveal that films are p-type semiconductors, the dark conductivity increases from 3.07 x10(-4) (Omega.cm)(-1) in film prepared with methanol to 5.15 x10(-3 )(Omega.cm)(-1) when using distilled water. We inferred that using distilled water leads to films with better quality than methanol as solvent.