论文标题
基于烷基铵的钙钛矿的光电和稳定性
Optoelectronic and stability properties of quasi-2D alkylammonium based perovskites
论文作者
论文摘要
使用密度功能理论（DFT）计算研究了准2D烷基铵的电子和稳定性特性，并对选定的化合物类别进行了实验验证。我们的分析集中于公式（a）$ _ 2 $（$'$）$ _ {n-1} $ pb $ _n $ _n $ x $ _ {3n+1} $的钙钛矿结构，带有大阳离子A =丁基 - ，丁烷 - ，pentyl-，pentyl-，pentyl-，hexylium（ba，ba，pa，pa，pa，pa，hxa），$ $ y $ nylym a shyyyy y rethylym'乙基铵，鸟嘌呤（MA，FA，EA，GA）和卤素X = I，Br，Cl。对于条带结构，稳定性和缺陷形成能，概述了卤素离子的作用。发现吸收效率与稳定性的两个相反趋势，后者根据可能的降解机制进行评估。实验验证是在基于五半阳离子的准2D perovskites上执行的，即：（ pa）$ _ 2 $ _ 2 $ pbx $ _4 $和（pa）$ _ 2 $（ma）PB $ _2 $ _2 $ x $ _7 $，由Antisolvent-assisted-Assisted-Assisted Vapor vapor crystallization合成。结构和光学分析与基于DFT的计算有关。此外，与理论预测一致，热重分析显示了溴化物和基于氯化物的化合物的稳定性增强。
Electronic and stability properties of quasi-2D alkylammonium perovskites are investigated using density functional theory (DFT) calculations and validated experimentally on selected classes of compounds. Our analysis is focused on perovskite structures of formula (A)$_2$(A$'$)$_{n-1}$Pb$_n$X$_{3n+1}$, with large cations A = butyl-, pentyl-, hexylammonium (BA, PA, HXA), small cations A$'$ = methylammonium, formamidinium, ethylammonium, guanidinium (MA,FA,EA,GA) and halogens X = I, Br, Cl. The role of the halogen ions is outlined for the band structure, stability and defect formation energies. Two opposing trends are found for the absorption efficiency versus stability, the latter being assessed with respect to possible degradation mechanisms. Experimental validation is performed on quasi-2D perovskites based on pentylammonium cations, namely: (PA)$_2$PbX$_4$ and (PA)$_2$(MA)Pb$_2$X$_7$, synthesized by antisolvent-assisted vapor crystallization. Structural and optical analysis are inline with the DFT based calculations. In addition, the thermogravimetric analysis shows an enhanced stability of bromide and chloride based compounds, in agreement with the theoretical predictions.
