Structural, optical, optoelectrical and photovoltaic properties of the thermally evaporated Sb₂Se₃ thin films

Abstract

Production of inexpensive and promising light-absorbing materials is very important in photovoltaic device applications. In this study, we investigate the preparation of good-quality antimony selenide (Sb₂Se₃) thin films via thermal evaporation procedure with different thicknesses (241, 315, 387 and 429 nm). The analysis of the X-ray diffraction examination of the Sb₂Se₃ thin films demonstrates that the as-deposited Sb₂Se₃ thin films are polycrystalline with a single-phase orthorhombic structure. The elemental composition analysis of the evaporated Sb₂Se₃ thin film established that the as-deposited film has near stoichiometric composition of the compound. The linear optical results of the Sb₂Se₃ thin films revealed that the films show optical direct transitions and optical energy gaps in the range 1.12–1.05. The optoelectrical parameters of the Sb₂Se₃ thin films (ratio of the charge carrier concentrations to the effective mass $N_{\text{opt}} m$, optical electronegativity $\xi_{\text{opt}}$ and the lattice dielectric constant, $\varepsilon_{L}$) were estimated. The analysis of nonlinear optical parameters of the Sb₂Se₃ thin films reveals the increase of the film thickness combined with increase in the nonlinear refractive index. The Al/n-Si/Sb₂Se₃/Ag heterojunction was produced by the thermal evaporation technique. The photovoltaic constants of the Al/n-Si/Sb₂Se₃/Ag heterojunction were estimated from the J–V curve and demonstrate a solar efficiency of 4.03%.