Effectiveness of Sn-addition on optical properties and physicochemical parameters of SnxSb2-xSe3 thin films

This research work is allocated to prepare the novel thin SnxSb2-xSe3 films, TSSe by thermal evaporation pro-cedure at various Sn-content, where 0 <= x <= 2 at.%. The field-emission scanning electron microscope has been used to investigate the surface nature of these SnxSb2-xSe3 films. X-ray diffraction revealed that all TSSe films disclosed that the films have the polycrystalline nature with the orthorhombic structure without regard to the Sn-content. The optical characteristics of these layers were studied via transmission and reflection spectrophoto-metric measurements. The Archimedes' principle has been used to measure the density of samples, which was found that its values increase from 5.766 gm/cm3 to 6.136 gm/cm3. Along with, the molar volume decreases from 83.316 cm3/mol to 77.291 cm3/mol. The optical energy gap investigation of thin SnxSb2-xSe3 layers indicated that these layers exposed a direct allowed electronic transition. The optical band-gap energy reduces from 1.191 eV to 1.050 eV, while the band tail width increases from 0.093 eV to 0.155 eV by boosting the Sn-content. Impact of Sn-content on the linear optical parameters also refers to increasing the absorption coefficient, refractive index (from 3.2086 to 3.3317), molar refraction (from 0.756 to 0.771), the interaction strength be-tween the electrons and photons (from 2.439 to 4.065). On the contrary, the steepness parameter, reflection factor, and electronic polarizability decrease as Sn-percentages increase from 0.0 to 2.0 at%. In addition, many other parameters have been discussed, like the optical conductivity, the real and imaginary parts of the dielectric indices, some nonlinear optical parameters, and the semiconductor-type of these films, which detect that they are p-type semiconductors. The investigated parameters and properties showed that these films can be used in many optical applications, like solar cells, photodetectors, batteries, memory devices, and others.

Automated summary

This research aims to prepare novel thin SnxSb2-xSe3 films, TSSe, with varying Sn-content through thermal evaporation. Field-emission scanning electron microscope was used to study the surface properties of these films, while X-ray diffraction revealed their polycrystalline nature with an orthorhombic structure. Optical characteristics were analyzed through transmission and reflection spectrophoto-metric measurements. The investigation of various parameters and properties indicated that these films can be utilized in a wide range of optical applications.