SnS and SnS2 films by direct-coating from same molecular ink

SnS and SnS2 thin films have been direct-coated on glass from similar inks prepared by dissolving 1:1 M ratio of SnCl2 and thiourea (TU) in methanol (MEI) or ethylene glycol (EGI). Films were deposited on glass by dropcasting, drying and finally heating in air from 200 to 360 degrees C. EGI-precursor films heated from 300 to 340 degrees C yielded mixture of SnS2 and SnS while only SnS films were obtained above 360 degrees C. However, MEI produced SnS2 films above 200 degrees C. SnS and SnS2 films have band gaps of 1.45 and 2.4 eV, respectively. The SnS films were ntype with conductivity, mobility and electron concentration of 1-2 S/cm, 2 cm2/V.s and 1018 cm-3, respectively. The SnS2 films were also n-type with conductivity, mobility and electron concentration of -10-5 S/cm, 0.6 cm2/ V.s and -1014 cm-3, respectively. Formation of SnSx films were explained on the basis of thermolysis of Sn}2-TU complex in air.

Automated summary

Thin films of SnS and SnS2 were directly coated on glass using similar inks prepared from dissolving SnCl2 and thiourea in methanol or ethylene glycol. The films exhibited different electrical properties as n-type semiconductors, with varying conductivity, mobility, and electron concentration levels.