Liao Qiaohui, Chen Jielin, Zhou Liya, Wei Tingting, Zhang Le, Chen Di, Huang Furong, Pang Qi, Zhang Jin Zhong
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, Guangxi P. R. China.
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States.
J Phys Chem Lett. 2020 Oct 1;11(19):8392-8398. doi: 10.1021/acs.jpclett.0c02553. Epub 2020 Sep 22.
Lead-free double perovskites (DPs) with excellent moisture, light, and heat stability have been explored as alternatives to toxic lead halide perovskite (APbX) (A for monovalent cation and X for Cl, Br, or I). However, the bandgaps of the current DPs are generally larger and either indirect or direct forbidden, which leads to weak visible light absorption and limitation for photovoltaic and other optoelectronic applications. Herein, we demonstrate the first synthesis of Cu-doped CsAgInCl double perovskite nanocrystals via a facile hot-injection solution approach. The electronic bandgap can be dramatically tuned from ∼3.60 eV (CsAgInCl, parent) to ∼2.19 eV (Cu-doped CsAgInCl) by varying the Cu doping amount. We conclude that the decrease of bandgap is attributed to the overlap of the Ag-d/In-p/Cl-p orbitals and the Cu-3d orbitals in the valence band. The wide tunability of the optical and electronic properties makes Cu-Doped CsAgInCl DP NCs promising candidates for future optoelectronic device applications.
具有出色的湿气、光和热稳定性的无铅双钙钛矿（DPs）已被探索作为有毒卤化铅钙钛矿（APbX）（A代表单价阳离子，X代表Cl、Br或I）的替代品。然而，当前DPs的带隙通常较大，要么是间接带隙，要么是直接禁带，这导致可见光吸收较弱，限制了其在光伏和其他光电器件中的应用。在此，我们展示了通过简便的热注入溶液法首次合成铜掺杂的CsAgInCl双钙钛矿纳米晶体。通过改变铜掺杂量，电子带隙可从约3.60电子伏特（CsAgInCl，母体）显著调谐至约2.19电子伏特（铜掺杂的CsAgInCl）。我们得出结论，带隙的减小归因于价带中Ag-d/In-p/Cl-p轨道与Cu-3d轨道的重叠。光学和电子性质的广泛可调性使得铜掺杂的CsAgInCl DP纳米晶体成为未来光电器件应用的有前途的候选材料。
