Zn1-xMgxO: Band Structure and Simulation as Window Layer for CdTe Solar Cell by SCAPS Software

HE Xu, REN Sheng-Qiang, LI Chun-Xiu, WU Li-Li, ZHANG Jing-Quan, DU Zheng
2018 Journal of Inorganic Materials  
Zn 1-x Mg x O(ZMO)(0≤x≤0.25)合金的能 带结构。计算表明: 随着 Mg 组分增加, ZMO 化合物的导带底及费米能级均向真空能级方向移动, 带隙增宽。基于 理论计算得到 ZMO 的能带结构参数, 使用 SCAPS 软件对 ZMO 作窗口层的 CdTe 薄膜太阳电池的性能进行了仿真 模拟, 并将研究结果与 CdS 作窗口层的 CdTe 太阳电池的性能进行了比较。结果表明: Mg 在 ZMO 中的含量 0≤x ≤0.125 时, ZMO/CdTe 太阳电池具有比 CdS/CdTe 太阳电池更高的开路电压和短路电流密度; ZMO 的导带底高出 CdTe 导带底约 0.13 eV 时, CdTe 薄膜太阳电池的转换效率最高, 达到 18.29%。这些结果为高效率碲化镉薄膜太阳 电池的结构设计和器件制备提供了理论指导。 关 键 词: Zn 1-x Mg x O; 能带结构; 薄膜太阳电池; 转换效率 中图分类号: O447 文献标识码: A Abstract: In this paper, the band structure of Zn 1-x Mg x
more » ... f Zn 1-x Mg x O(ZMO) alloy with different Mg compositions by using first-principles calculations with GGA+U method was studied. The calculation results show that position of conduction band offset and Fermi level of Zn 1-x Mg x O move towards the vacuum level while the band gap becomes wider with the increasing Mg concentration. Based on theoretical calculation results of ZMO, ZMO/CdTe, CdS/CdTe solar cells were modeled using SCAPS software and its device performances were simulated and analyzed in detail. The results indicate that the conversion efficiency of CdTe solar cell with ZMO is higher than that of solar cell with CdS due to the high open circuit voltage and short circuit current density when x in Zn 1-x Mg x O is in the range of 00.125. Efficiency of CdTe solar cells with ZMO reaches 18.29% because the recombination decreases obviously resulting from appropriate conduction band offset about 0.13 eV at ZMO/CdTe interface. These data provide a theoretical guidance for design and fabrication of high efficiency CdTe solar cells.
doi:10.15541/jim20170349 fatcat:biokgitpvnahdhm7dlfbugkgcm