Study of Copper Tin Selenide Nanoparticles of Milled Powder and Thin Films
Résumé
Nanoparticles Cu 2 SnSe 3 alloys were synthesized by mechanical alloying from mixtures of pure crystalline Cu, Sn and Se powders using a low cost planetary ball milling process optimizing the milling duration and the rotational speed. The properties of Cu 2 SnSe 3 (CTSe) thin films deposited by thermal evaporation from this powder on glass substrate at T s = 400°C were investigated. Powders and films were analyzed by X-ray diffraction (XRD), scanning electron microscopy(SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), to determine their microstructure, morphology, chemical compositions and root-mean-square (RMS) roughness. XRD analysis revealed that all samples crystallize in polycrystalline nature with cubic structure and lattice parameter a = 5.68 Å. The optical measurements were carried out in the [500-2500nm] wavelength range and were determined from spectral transmission data. Optical measurements showed that the deposited layers had a relatively high absorption coefficient of 10 4 cm -1 and the direct energy band gap was found to be around Eg =1.29eV. The suitable p-type conductivity of CTSe thin films was confirmed by hot probe method. Other electrical parameters (carrier concentration n p = 10.04x10 18 cm -3 , electrical resistivity ρ = 30.49x10 -2 Ω cm and mobility μ H = 94.33 cm 2 /V s) were measured at room temperature.