Enhancement of photovoltaic efficiency in CdSexTe1-x (where 0 ≤ x ≤ 1): insights from density functional theory
Enhancement of photovoltaic efficiency in CdSexTe1-x (where 0 ≤ x ≤ 1): insights from density functional theory
复制标题
DOI：
10.1088/1361-648x/ab5bba
复制
发表时间：
2020-03-20
影响因子：
2.7
通讯作者：
Goddard, Pooja
中科院分区：
文献类型：
--
作者：
Watts, Michael J.;Fiducia, Thomas A. M.;Goddard, Pooja
CdTe光伏效率的最新进展来自硒的分级，它减少了带隙并显着提高了载流子寿命。在这项工作中，密度泛函理论计算，以了解硒合金的结构和电子效应。采用特殊的准随机结构来模拟Se阴离子的随机分布。随着硒浓度的增加，晶格参数呈线性下降，符合维加德定律。模拟的带隙弯曲与实验值吻合较好。硒本身不会在带隙中引入任何缺陷态，也没有发现伽玛点周围带结构的明显变化。带偏移值表明在x处CdSeTe/MgZnO界面上的复合减少
Recent advancements in CdTe photovoltaic efficiency have come from selenium grading, which reduces the band gap and significantly improves carrier lifetimes. In this work, density functional theory calculations were performed to understand the structural and electronic effects of Se alloying. Special quasirandom structures were used to simulate a random distribution of Se anions. Lattice parameters decrease linearly as Se concentration increases in line with Vegard's Law. The simulated band gap bowing shows strong agreement with experimental values. Selenium, by itself, does not introduce any defect states in the band gap and no significant changes to band structure around the Gamma point are found. Band offset values suggest a reduction of recombination across the CdSeTe/MgZnO interface at x