SILAR Deposition of Sns Thin Films for Possible Device Applications

Abstract

Successive Ionic Layer Adsorption and Reaction (SILAR) was used to deposit tin sulphide (SnS) thin films on glass substrates at temperature of 450C.Sodium thiosulphateNa2S2O3solution was used as the anionic precursor, tin chloride SnCl2 solution as the cationic precursor and EDTA as complexing agent. The samples were subjected to annealing at the temperature range of 2000C and 250oC). High transmittance values were obtained in both Samples C and D in the UV(70% -72%) and (75% - 89%) respectively atthe wavelength range of (350nm-400nm) which maintains linear characteristics through the visible to near infrared regions (NIR) of the electromagnetic spectrum. This high transmittance implies that it can be useful in the areas of solar energy and opto-electronic applications. The Energy band gap (Eg) is obtained using the relation (αhv)2= A (hv-Eg) where A is constant, hv is the photon energy, Eg is the energy band gap and α is the absorption coefficient. Direct band gap value of 2.90±0.05eV is obtained for sample C while a direct band gap of 2.70±0.05eV is obtained for sample D. The two samples have average band gap of 2.8±0.05eV.