Defect properties of Sb2Se3 thin film solar cells and bulk crystals
Defect properties of Sb2Se3 thin film solar cells and bulk crystals
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DOI：
10.1063/5.0012697
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发表时间：
2020-06-29
影响因子：
4
通讯作者：
Major, Jonathan D.
中科院分区：
文献类型：
--
作者：
Hobson, Theodore D. C.;Phillips, Laurie J.;Major, Jonathan D.
作为光伏器件中的吸收剂，尽管人们对 Sb2Se3 的电子缺陷缺乏基本了解，但它已迅速实现了令人印象深刻的功率转换效率。在这里，我们提出了对块状晶体和薄膜器件材料中深能级缺陷的深能级瞬态光谱（DLTS）研究。对布里奇曼生长的 n 型块状晶体的 DLTS 研究揭示了导带边缘以下 358、447、505 和 685meV 处的陷阱。其中，447 和 505meV 处能量接近的对只能使用等温瞬态光谱（速率窗口变化）方法来解析。完成的 Sb2Se3 薄膜太阳能电池显示出类似的陷阱光谱，在 378、460 和 690meV 处识别出陷阱。薄膜和块状晶体材料中缺陷的相似性质意味着 Sb2Se3 中多晶性的影响最小，支持良性晶界的概念。
As an absorber in photovoltaic devices, Sb2Se3 has rapidly achieved impressive power conversion efficiencies despite the lack of fundamental knowledge about its electronic defects. Here, we present a deep level transient spectroscopy (DLTS) study of deep level defects in both bulk crystal and thin film device material. DLTS study of Bridgman-grown n-type bulk crystals revealed traps at 358, 447, 505, and 685meV below the conduction band edge. Of these, the energetically close pair at 447 and 505meV could only be resolved using the isothermal transient spectroscopy (rate window variation) method. A completed Sb2Se3 thin film solar cell displayed similar trap spectra with traps identified at 378, 460, and 690meV. The comparable nature of defects in thin film and bulk crystal material implies that there is minimal impact of polycrystallinity in Sb2Se3 supporting the concept of benign grain boundaries.