Phase Transitions in SnxSy Thin Films Induced by Nd:YAG Pulsed Laser Radiation
7th International Conference on Silicate Materials "BaltSilica 2016" 2016
Līga Orlova, Andrii Voznyi, Volodymyr Kosyak, Anatoliy Opanasyuk, Artūrs Medvids, Pāvels Onufrijevs, Gundars Mežinskis

SnxSy binary compounds have a high potential for applications in many optoelectronic devices. Polycrystalline SnS thin film with a band gap above 1.1 eV is considered as a new absorber material for solar cells instead of conventional CdTe and CIGS. This compound is characterised by p-type electrical conductivity and high mobility of free charge carriers. In the same time, SnS2 and Sn2S3 are n-type semiconductors with band gaps of 2.2 eV and 0.95 eV, respectively. Such properties of SnS allow using it as a window layer in solar cells. Other important advantages of SnS related compounds are their low-cost, earth abundance and non-toxicity. The present research is focused on the elaboration of laser technology for phase transitions in SnS-based compounds. The SnS2 films were deposited on ITO coated glass substrates by close spaced sublimation method. The Field Emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDS) analysis, X-ray diffraction (XRD) and Raman spectrum analysis show that non-irradiated films are single phase of SnS2 and consists of plate-like crystallites randomly oriented in a plane parallel to the surface. Such growth orientation is preferable for thin films solar cells. The second harmonic of Nd:YAG laser with wavelength 532 nm was used for irradiation of the samples. It was shown that laser irradiation leads to evaporation of sulphur from the surface and formation of SnS and Sn2S3 phases confirmed by the XRD and Raman spectroscopy methods. The study of samples cross section by EDS analysis reveals that in the case of irradiation with intensity of 8.5 MW/cm2 the SnS layer is formed only at the surface of the initial SnS2 thin film. While the application of more intensive radiation of 11.5 MW/cm2 leads to the changes in chemical composition for whole thin film. To conclude, the possibility to induce phase transitions in SnS2 polycrystalline thin film by Nd:YAG laser radiation was shown.


Keywords
Phase Transitions, SnS, thin films, Nd:YAG laser

Grase, L., Voznyi, A., Kosyak, V., Opanasyuk, A., Medvids, A., Onufrijevs, P., Mežinskis, G. Phase Transitions in SnxSy Thin Films Induced by Nd:YAG Pulsed Laser Radiation. In: 7th International Conference on Silicate Materials "BaltSilica 2016", Lithuania, Kaunas, 26-27 May, 2016. Kaunas: 2016, pp.60-60. ISSN 2243-6057.

Publication language
English (en)
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