Growth and characterization of tin selenide films synthesized by low cost technique for photovoltaic device applications

Tin selenide was synthesized by mechanical alloying method and the films were grown by economic screen-printing method on glass substrate. The source materials used for the preparation of films were tin selenide and stannic chloride. The structural, elemental, morphological, optical and electrical properties of the prepared films were investigated by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM), Raman spectroscopy, UV–Vis spectrometry, two point probe method and Hall effect measurement technique. XRD analysis confirms that the films were polycrystalline in nature, exhibiting orthorhombic structure with most prominent orientation of grains along (111) and (112) direction. EDAX analysis indicates that the prepared films were nearly stoichiometric in nature. SEM studies show that smaller grains were assembled to form a bunch of bigger size. Raman spectra were used to observe the characteristic vibrational modes of SnSe. Direct type of transition of band gap was confirmed by reflection spectra occurring at 1.1 eV. The dark electrical conductivity and photoconductivity reveals that the films were semiconducting in behaviour. The carrier type of films was determined by Hall effect measurement.