Laser induced SnS2-SnS phase transition and surface modification in SnS2 thin films

The SnS2 single-phase thin films were obtained by the close-spaced vacuum sublimation method. Laser irradiation of the SnS2 films provides evaporation of sulphur and hence phase transition to the SnS phase. Irradiation of the sample leads to the smoothing of the surface of the film. The electrical measurements of the irradiated samples show diode behaviour of the current-voltage dependencies. Two-layer n-SnS2/p-SnS heterojunction structure was formed.A thin film of SnS2 obtained by close-spaced vacuum sublimation was irradiated by an Nd:YAG laser (λ = 532 nm) using two intensities of laser radiation of 8.5 MW/cm2 and 11.5 MW/cm2. It was shown that laser irradiation leads to evaporation of sulphur from the surface, and the formation of SnS and Sn2S3 phases. The study of samples’ cross-section by energy dispersive X-ray analysis reveals that in the case of irradiation at 8.5 MW/cm2 intensity, the SnS layer is formed only at the surface of the initial SnS2 thin film. The application of more intensive radiation of 11.5 MW/cm2 leads to changes in chemical composition for the entire thin film. The formation of the predominant SnS phase, which includes a small amount of Sn2S3, was confirmed by the X-ray diffraction and Raman spectroscopy methods, as well as by measurements of optical reflectance and transmittance spectra. It was established that laser irradiation of the samples leads to the coalescence of grains accompanied by smoothing of the surface. The current-voltage characteristics of the ITO/SnxSy/Al samples show an ohmic behaviour in the case of non-irradiated intensity samples; for irradiated samples, the diode behaviour of I-V curves was observed. This is considered as evidence of the formation of p-SnS/n-SnS2 heterojunction by laser irradiation.This work was supported by the Ministry of Education and Science of Ukraine (Grant # 0115U000665c). A. Voznyi and Dr. V. Kosyak acknowledges Erasmus Mundus Ianus II program

Post-growth treatment of SnxSy thin films

In this study, the effect of post-growth thermal annealing and laser irradiation on phase composition, structural, optical and electrical properties of SnS2 obtained by the close-spaced sublimation on ITO substrates was studied. It was found, by using EDS, XRD and Raman methods that as-grown samples have single phase SnS2 structure and their chemical composition is close to stoichiometric

Laser induced SnS2-SnS phase transition and surface modification in SnS2 thin films

The SnS2 single-phase thin films were obtained by the close-spaced vacuum sublimation method. Laser irradiation of the SnS2 films provides evaporation of sulphur and hence phase transition to the SnS phase. Irradiation of the sample leads to the smoothing of the surface of the film. The electrical measurements of the irradiated samples show diode behaviour of the current-voltage dependencies. Two-layer n-SnS2/p-SnS heterojunction structure was formed.A thin film of SnS2 obtained by close-spaced vacuum sublimation was irradiated by an Nd:YAG laser (λ = 532 nm) using two intensities of laser radiation of 8.5 MW/cm2 and 11.5 MW/cm2. It was shown that laser irradiation leads to evaporation of sulphur from the surface, and the formation of SnS and Sn2S3 phases. The study of samples’ cross-section by energy dispersive X-ray analysis reveals that in the case of irradiation at 8.5 MW/cm2 intensity, the SnS layer is formed only at the surface of the initial SnS2 thin film. The application of more intensive radiation of 11.5 MW/cm2 leads to changes in chemical composition for the entire thin film. The formation of the predominant SnS phase, which includes a small amount of Sn2S3, was confirmed by the X-ray diffraction and Raman spectroscopy methods, as well as by measurements of optical reflectance and transmittance spectra. It was established that laser irradiation of the samples leads to the coalescence of grains accompanied by smoothing of the surface. The current-voltage characteristics of the ITO/SnxSy/Al samples show an ohmic behaviour in the case of non-irradiated intensity samples; for irradiated samples, the diode behaviour of I-V curves was observed. This is considered as evidence of the formation of p-SnS/n-SnS2 heterojunction by laser irradiation.This work was supported by the Ministry of Education and Science of Ukraine (Grant # 0115U000665c). A. Voznyi and Dr. V. Kosyak acknowledges Erasmus Mundus Ianus II program

Post-growth treatment of SnxSy thin films

In this study, the effect of post-growth thermal annealing and laser irradiation on phase composition, structural, optical and electrical properties of SnS2 obtained by the close-spaced sublimation on ITO substrates was studied. It was found, by using EDS, XRD and Raman methods that as-grown samples have single phase SnS2 structure and their chemical composition is close to stoichiometric