Identification of lead vacancy defects in lead halide perovskites.
Identification of lead vacancy defects in lead halide perovskites.
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DOI：
10.1038/s41467-021-25937-1
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发表时间：
2021-09-22
影响因子：
16.6
通讯作者：
Egger W
中科院分区：
文献类型：
--
作者：
Keeble DJ;Wiktor J;Pathak SK;Phillips LJ;Dickmann M;Durose K;Snaith HJ;Egger W
钙钛矿型光伏技术发展迅速，但点缺陷方面的问题仍然存在：虽然实验检测到了电活性缺陷的存在，但还没有实验证实的显微鉴定的报道。在这里，我们用正电子湮没寿命谱结合密度泛函理论确定了MAPbI_3(MA， = ，CH_3NH_3+)中的铅单空位缺陷。薄膜和单晶样品均表现出以正电子捕获为主的铅空位缺陷，其最小缺陷密度为3 × 1015 cm−3。在少数样品中也有空位复合体的陷阱，但没有观察到对MA离子空位的陷阱。我们的实验结果支持了其他第一性原理研究的预测，即深能级、空穴陷阱、点缺陷是MAPbI3中最稳定的缺陷之一。这种对卤化物钙钛矿深能级本征缺陷的直接检测和识别，在技术上相关的浓度，将使进一步研究缺陷驱动的机制成为可能。点缺陷影响了杂化钙钛矿的电子性能，但还没有实验鉴定的报道。在这里，作者首次借助密度泛函理论，用正电子湮没寿命谱确定了MAPbI_3中铅的单空位缺陷。
Perovskite photovoltaics advance rapidly, but questions remain regarding point defects: while experiments have detected the presence of electrically active defects no experimentally confirmed microscopic identifications have been reported. Here we identify lead monovacancy (VPb) defects in MAPbI3 (MA = CH3NH3+) using positron annihilation lifetime spectroscopy with the aid of density functional theory. Experiments on thin film and single crystal samples all exhibited dominant positron trapping to lead vacancy defects, and a minimum defect density of ~3 × 1015 cm−3 was determined. There was also evidence of trapping at the vacancy complex in a minority of samples, but no trapping to MA-ion vacancies was observed. Our experimental results support the predictions of other first-principles studies that deep level, hole trapping, , point defects are one of the most stable defects in MAPbI3. This direct detection and identification of a deep level native defect in a halide perovskite, at technologically relevant concentrations, will enable further investigation of defect driven mechanisms. Point defects compromise the electronic performance of hybrid perovskites, yet no experimental identifications have been reported. Here, the authors, for the first time, identify lead monovacancy defect in MAPbI3 using positron annihilation lifetime spectroscopy with the aid of density functional theory.
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影响因子：
56.9
作者：
Lee, Michael M.;Teuscher, Joel;Snaith, Henry J.
通讯作者：
Snaith, Henry J.
影响因子：
3.7
作者：
Hsieh, Hsiao-Chi;Hsiow, Chuen-Yo;Thien-Phap Nguyen
通讯作者：
Thien-Phap Nguyen
ABINIT 软件包的最新发展
影响因子：
6.3
作者：
Gonze, X.;Jollet, F.;Zwanziger, J. W.
通讯作者：
Zwanziger, J. W.
影响因子：
3.7
作者：
Barbiellini, B;Puska, MJ;Nieminen, RM
通讯作者：
Nieminen, RM
影响因子：
3.3
作者：
Hugenschmidt, Christoph;Piochacz, Christian;Schreckenbach, Klaus
通讯作者：
Schreckenbach, Klaus