Rondiya Sachin R, Mali Sawanta S, Roy Anurag, Inwati Gajendra Kumar, Rahane Ganesh K, Jadhav Yogesh A, Suresh Sunil, Debnath Tushar, Hong Chang Kook, Dzade Nelson Y
School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Wales, UK.
Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India.
Phys Chem Chem Phys. 2023 Nov 1;25(42):29050-29060. doi: 10.1039/d3cp02935b.
This study investigates the incorporation of Ba at a low concentration into CsPbIBr, resulting in the formation of mixed CsPbBaIBr perovskite films. Photovoltaic devices utilizing these Ba-doped CsPbIBr (Ba-CsPbIBr) perovskite films achieved a higher stabilized power conversion efficiency of 14.07% compared to 11.60% for pure CsPbIBr films. First-principles density functional theory calculations indicate that the improved device performance can be attributed to the efficient transport of conduction electrons across the interface between Ba-CsPbIBr and the TiO electron transporting layer (ETL). The Ba-CsPbIBr/TiO interface exhibits a type-II staggered band alignment with a smaller conduction band offset (CBO) of 0.25 eV, in contrast to the CsPbIBr/TiO interface with a CBO of 0.48 eV. The reduced CBO at the Ba-CsPbIBr/TiO interface diminishes the barrier for conduction electrons to transfer from the Ba-CsPbIBr layer to the TiO layer, facilitating efficient charge transport.
本研究探究了将低浓度的钡掺入CsPbIBr中，从而形成混合的CsPbBaIBr钙钛矿薄膜。与纯CsPbIBr薄膜11.60%的效率相比，利用这些掺钡的CsPbIBr（Ba-CsPbIBr）钙钛矿薄膜的光伏器件实现了更高的14.07%的稳定功率转换效率。第一性原理密度泛函理论计算表明，器件性能的改善可归因于传导电子在Ba-CsPbIBr与TiO电子传输层（ETL）之间的界面上的有效传输。与具有0.48 eV导带偏移（CBO）的CsPbIBr/TiO界面相比，Ba-CsPbIBr/TiO界面呈现出II型交错能带排列，其导带偏移较小，为0.25 eV。Ba-CsPbIBr/TiO界面处减小的CBO降低了传导电子从Ba-CsPbIBr层转移到TiO层的势垒，促进了有效的电荷传输。
