Schwartz Heidi A, Laurenzen Hannah, Marzouk Asma, Runkel Manuel, Brinkmann Kai Oliver, Rogalla Detlef, Riedl Thomas, Ashhab Sahel, Olthof Selina
Department of Chemistry, University of Cologne, Greinstrasse 4-6, 50939 Cologne, Germany.
Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 34110, Doha 122104, Qatar.
ACS Appl Mater Interfaces. 2021 Jan 27;13(3):4203-4210. doi: 10.1021/acsami.0c20285. Epub 2021 Jan 12.
We investigate all-inorganic perovskite CsPbSnBr thin films to determine the variations in the band gap and electronic structure associated with the Pb/Sn ratio. We observe that the band gap can be tuned between 1.86 eV ( = 0) and 2.37 eV ( = 1). Intriguingly, this change is nonlinear in , with a bowing parameter of 0.9 eV; furthermore, a slight band gap narrowing is found for low Pb content (minimum ∼ 0.3). The wide tunability of the band gap makes CsPbSnBr a promising material, e.g., for a wide-gap subcell in tandem applications or for color-tunable light-emitting diodes. Employing photoelectron spectroscopy, we show that the valence band varies with the Pb/Sn ratio, while the conduction band is barely affected.
我们研究了全无机钙钛矿CsPbSnBr薄膜，以确定与Pb/Sn比率相关的带隙和电子结构变化。我们观察到带隙可在1.86 eV（x = 0）和2.37 eV（x = 1）之间调节。有趣的是，这种变化在x中是非线性的，弯曲参数为0.9 eV；此外，对于低Pb含量（最小x ∼ 0.3），发现带隙略有变窄。带隙的广泛可调性使CsPbSnBr成为一种有前途的材料，例如用于串联应用中的宽隙子电池或用于颜色可调发光二极管。利用光电子能谱，我们表明价带随Pb/Sn比率而变化，而导带几乎不受影响。
