An Above-Room-Temperature Ferroelectric Organo-Metal Halide Perovskite: (3-Pyrrolinium)(CdCl3)

• Published in: Angewandte Chemie (International ed.) Vol. 53; no. 42; pp. 11242 - 11247
• Main Authors: Ye, Heng-Yun, Zhang, Yi, Fu, Da-Wei, Xiong, Ren-Gen
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 13.10.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: domains; Electric potential; Ferroelectric materials; Ferroelectricity; ferroelectrics; Halides; Perovskites; phase transitions; Photovoltaic cells; Photovoltaic effect; polarization switching; Solar cells; Stacking; perovskites; ferroelectrics; domains; phase transitions; polarization switching
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201406810

Hybrid organo–metal halide perovskite materials, such as CH3NH3PbI3, have been shown to be some of the most competitive candidates for absorber materials in photovoltaic (PV) applications. However, their potential has not been completely developed, because a photovoltaic effect with an anomalously large voltage can be achieved only in a ferroelectric phase, while these materials are probably ferroelectric only at temperatures below 180 K. A new hexagonal stacking perovskite‐type complex (3‐pyrrolinium)(CdCl3) exhibits above‐room‐temperature ferroelectricity with a Curie temperature Tc=316 K and a spontaneous polarization Ps=5.1 μC cm−2. The material also exhibits antiparallel 180° domains which are related to the anomalous photovoltaic effect. The open‐circuit photovoltage for a 1 mm‐thick bulky crystal reaches 32 V. This finding could provide a new approach to develop solar cells based on organo–metal halide perovskites in photovoltaic research. Changing phases: A hexagonal stacking organo–metal halide perovskite‐type complex (3‐pyrrolinium)(CdCl3) was designed. It shows above‐room‐temperature ferroelectricity with a Curie temperature Tc=316 K, an anomalous photovoltaic effect with an open‐circuit voltage of 32 V, and the formation of stripe‐like electric domains as a result of spontaneous polarization measured by piezoresponse force microscopy (see picture).