Published online by Cambridge University Press: 01 February 2011
The electronic properties of polycrystalline CuIn1-xAlxSe2 (CIAS) films, which are incorporated as the absorber layer in photovoltaic devices, have been studied to better understand limitations on device performance. These studies have shown that compared to lower Al content films and to CuIn1-yGaySe2films, films with x ≥ 0.29 are relatively intrinsic, spatially nonuniform, and have broader bandtails characterized by much higher Urbach energies. This indicates that the CIAS films with x ≥ 0.29 are significantly more disordered than lower Al content CIAS or corresponding CIGS films, which likely negatively impacts the resulting photovoltaic device performance.