Pandey Mohnish, Jacobsen Karsten W, Thygesen Kristian S
Center for Atomic-scale Materials Design (CAMD), Department of Physics, Technical University of Denmark , DK - 2800 Kongens Lyngby, Denmark.
Center for Nanostructured Graphene (CNG), Department of Physics, Technical University of Denmark , DK - 2800 Kongens Lyngby, Denmark.
J Phys Chem Lett. 2016 Nov 3;7(21):4346-4352. doi: 10.1021/acs.jpclett.6b01998. Epub 2016 Oct 21.
Organic-inorganic halide perovskites have proven highly successful for photovoltaics but suffer from low stability, which deteriorates their performance over time. Recent experiments have demonstrated that low dimensional phases of the hybrid perovskites may exhibit improved stability. Here we report first-principles calculations for isolated monolayers of the organometallic halide perovskites (CHNH)MXY, where M = Pb, Ge, Sn and X,Y = Cl, Br, I. The band gaps computed using the GLLB-SC functional are found to be in excellent agreement with experimental photoluminescence data for the already synthesized perovskites. Finally, we study the effect of different defects on the band structure. We find that the most common defects only introduce shallow or no states in the band gap, indicating that these atomically thin 2D perovskites are likely to be defect tolerant.
有机-无机卤化物钙钛矿已被证明在光伏领域非常成功，但稳定性较低，这会随着时间的推移而降低其性能。最近的实验表明，混合钙钛矿的低维相可能具有更高的稳定性。在此，我们报告了有机金属卤化物钙钛矿(CHNH)MXY孤立单层的第一性原理计算，其中M = Pb、Ge、Sn，X、Y = Cl、Br、I。使用GLLB-SC泛函计算的带隙与已合成钙钛矿的实验光致发光数据高度吻合。最后，我们研究了不同缺陷对能带结构的影响。我们发现，最常见的缺陷在带隙中只引入浅能级或不引入能级，这表明这些原子级薄的二维钙钛矿可能具有缺陷耐受性。
