Understanding the Copassivation Effect of Cl and Se for CdTe Grain Boundaries
Understanding the Copassivation Effect of Cl and Se for CdTe Grain Boundaries
复制标题
了解 Cl 和 Se 对 CdTe 晶界的共钝化效应
DOI：
10.1021/acsami.1c06587
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发表时间：
2021
影响因子：
9.5
通讯作者：
Munshi, Amit H.
中科院分区：
文献类型：
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作者：
Shah, Akash;Nicholson, Anthony P.;Fiducia, Thomas A.;Abbas, Ali;Pandey, Ramesh;Liu, Junliang;Grovenor, Chris;Walls, John M.;Sampath, Walajabad S.;Munshi, Amit H.
碲化镉（CdTe）太阳能电池的氯钝化处理通过辅助CdTe晶粒边界处的电子-空穴载流子分离来提高器件性能。在将CdTe吸收剂层与硒合金化之后，观察到器件效率的进一步改善。高分辨率二次离子质谱（NanoSIMS）成像已被用来确定硒和氯的分布在碲化镉晶粒边界的硒梯度器件。基于密度泛函理论（DFT-1/2）的原子模型进一步揭示了在示例性（110）/（100）CdTe晶界处硒和氯的存在钝化了临界受主缺陷并导致晶界处的n型反转。的缺陷态分析提供了一个解释的能带对准结果中观察到的能带弯曲效应，从而阐明了在硒合金和Cl-钝化的CdTe太阳能电池中观察到的高效率的机制。
Chlorine passivation treatment of cadmium telluride (CdTe) solar cells improves device performance by assisting electron–hole carrier separation at CdTe grain boundaries. Further improvement in device efficiency is observed after alloying the CdTe absorber layer with selenium. High-resolution secondary ion mass spectroscopy (NanoSIMS) imaging has been used to determine the distribution of selenium and chlorine at the CdTe grain boundaries in a selenium-graded CdTe device. Atomistic modeling based on density functional theory (DFT-1/2) further reveals that the presence of selenium and chlorine at an exemplar (110)/(100) CdTe grain boundary passivates critical acceptor defects and leads to n-type inversion at the grain boundary. The defect state analysis provides an explanation for the band-bending effects observed in the energy band alignment results, thereby elucidating mechanisms for high efficiencies observed in Se-alloyed and Cl-passivated CdTe solar cells.