Similar Structural Dynamics for the Degradation of CH3NH3PbI3 in Air and in Vacuum

被引：78

作者：

Alberti, Alessandra ^{[1
]}

Deretzis, Ioannis ^{[1
]}

Pellegrino, Giovanna ^{[1
]}

Bongiorno, Corrado ^{[1
]}

Smecca, Emanuele ^{[1
]}

Mannino, Giovanni ^{[1
]}

Giannazzo, Filippo ^{[1
]}

Condorelli, Guglielmo Guido ^{[2
,3
]}

Sakai, Nobuya ^{[4
]}

Miyasaka, Tsutomu ^{[4
]}

Spinella, Corrado ^{[1
]}

La Magna, Antonino ^{[1
]}

机构：

[1] CNR, IMM Zona Ind, I-95121 Catania, Italy

[2] Univ Catania, I-95125 Catania, Italy

[3] INSTM UdR Catania, I-95125 Catania, Italy

[4] Toin Univ Yokohama, Grad Sch Engn, Aoba Ku, Yokohama, Kanagawa 2258503, Japan

来源：

CHEMPHYSCHEM | 2015年 / 16卷 / 14期

关键词：

crystal growth; X-ray diffraction; electron microscopy; perovskite phases; solid-state structures; PEROVSKITE SOLAR-CELLS; MIXED HALIDE PEROVSKITE; LEAD HALIDE; FILMS; TEMPERATURE; HYSTERESIS; HUMIDITY; DISORDER; CHLORIDE; TIO2;

D O I：

10.1002/cphc.201500374

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We investigate the degradation path of MAPbI(3) (MA=methylammonium) films over flat TiO2 substrates at room temperature by means of X-ray diffraction, spectroscopic ellipsometry, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The degradation dynamics is found to be similar in air and under vacuum conditions, which leads to the conclusion that the occurrence of intrinsic thermodynamic mechanisms is not necessarily linked to humidity. The process has an early stage, which drives the starting tetragonal lattice in the direction of a cubic atomic arrangement. This early stage is followed by a phase change towards PbI2. We describe how this degradation product is structurally coupled with the original MAPbI(3) lattice through the orientation of its constituent PbI6 octahedra. Our results suggest a slight octahedral rearrangement after volatilization of HI+CH3NH2 or MAI, with a relatively low energy cost. Our experiments also clarify why reducing the interfaces and internal defects in the perovskite lattice enhances the stability of the material.

引用

页码：3064 / 3071

页数：8