PHYSICAL PROPERTIES OF VACUUM EVAPORATED TIN SULFIDE THIN FILMS

摘要

Tin sulfide thin films were grown into vacuum evaporated onto soda lime and conducting glass substrates varying the substrate temperatures in the range of 150 to 350 0C. The samples were characterized for structure, morphology, optical, and opto-electronic properties. All the thin films showed at Herzenbergite structure with cells parameters close to the powder of SnS. The band gap varied from 1.19 to 1.26 eV as the substrate temperature increased. The grain size showed a very significant dependence on substrate temperature; the average grain size measured for films deposited were 23 to 52 nm. The Raman technique shows that the structure is SnS with traces of the Sn2S3 and SnS2 compounds. The EDS analysis shows the Sn/S ratio in the range of 1.01-1.1. Photosensitivity measurements revealed that films deposited at 3000C have better photoresponse, and the photoconductivity increased after annealing the films, the resistivity values varied of 103 to 105 Ω-cm with the increase of substrate temperature.