Structural, morphology and electrical properties of layered copper selenide thin film

Abstract

Abstract:Thin films of copper selenide (CuSe) were physically deposited layer-by-layer up to 5 layers using thermal evaporation technique onto a glass substrate. Various film properties, including the thickness, structure, morphology, surface roughness, average grain size and electrical conductivity are studied and discussed. These properties are characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), ellipsometer and 4 point probe at room temperature. The dependence of electrical conductivity, surface roughness, and average grain size on number of layers deposited is discussed.

Failure and Recovery Modes of Submicron Cu(In,Ga)Se2 Solar Cells with High Cu Content

“…In the growth using the well-established three-stage method, a temporary Cu-rich phase (liquid Cu 2– x Se) is always implemented to aid the mass transport to form large grains of CIGS . However, the residual Cu 2– x Se that remains after the growth of CIGS is reported as detrimental to the device performance because of its highly conductive nature. − In addition, the overall deficient Cu content is essential and beneficial for CIGS solar cells because it supplies Cu vacancies, which are the primary native defects contributing to the p-type conduction of CIGS . Therefore, it is widely reported that highly efficient CIGS absorbers are typically grown as a slightly Cu-poor material, with [Cu]/([In] + [Ga]) (CGI) ratios of 0.88–0.94. − Nonetheless, to the best of our knowledge, few studies have examined the effect of CGI value on photovoltaic properties of thin CIGS solar cells.…”