(1. 河南師范大學 物理與信息工程學院，新鄉(xiāng) 453007; 2. 河南省光伏材料重點實驗室，新鄉(xiāng) 453007)
摘 要: 采用基于密度泛函理論(DFT)框架下廣義梯度近似(GGA)的PBE平面波超軟贗勢方法，計算Cu2ZnSnS4(CZTS)和Cu2ZnSnSe4(CZTSe)的電子結(jié)構(gòu)和光學特性。計算并系統(tǒng)對比分析CZTS和CZTSe的態(tài)密度、吸收系數(shù)、復(fù)介電函數(shù)、復(fù)折射率、反射率、復(fù)電導率和能量損失函數(shù)隨光子能量的變化關(guān)系。結(jié)果表明，鋅黃錫礦型CZTS和CZTSe都是直接帶隙半導體材料。CZTS和CZTSe的態(tài)密度和光學特性的曲線非常相似，但CZTS的禁帶寬度比CZTSe的偏大，導致CZTS的各個光學特性曲線相對于CZTSe的略微向高能方向移動。
關(guān)鍵字: CZTS；CZTSe；第一性原理；能態(tài)密度；光學特性
（1. College of Physics and Information Engineering, Henan Normal University, Xinxiang 453007, China;
2. Henan Key Laboratory of Photovoltaic Materials, Xinxiang 453007, China）
Abstract:The electronic structure and optical properties of Cu2ZnSnS4(CZTS) and Cu2ZnSnSe4(CZTSe) were computed by means of plane wave ultrasoft pseudo-potential method with generalized gradient approximation (GGA) under the density functional theory (DFT). The density of states, adsorption coefficient, dielectric function, refractive index, reflectivity, conductivity and loss function were also calculated and compared. The results show that both the kesterite CZTS and the kesterite CZTSe are direct band gap semiconductors. The density of states and optical characteristic curves of CZTS and CZTSe are very similar. But all optical characteristic curves of CZTS slightly shift to high energy compared with that of CZTSe from its wider band gap.
Key words: CZTS; CZTSe; first-principles; density of states; optical properties
