Enhanced Photocurrent of All-Inorganic Two-Dimensional Perovskite Cs2PbI2Cl2via Pressure-Regulated Excitonic Features

Songhao Guo, Kejun Bu, Jiangwei Li, Qingyang Hu, Hui Luo, Yihui He, Yanhui Wu, Dongzhou Zhang, Yongsheng Zhao, Wenge Yang, Mercouri G. Kanatzidis, Xujie Lü*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

114 Scopus citations

Abstract

Pressure processing is efficient to regulate the structural and physical properties of two-dimensional (2D) halide perovskites which have been emerging for advanced photovoltaic and light-emitting applications. Increasing numbers of studies have reported pressure-induced and/or enhanced emission properties in the 2D halide perovskites. However, no research has focused on their photoresponse properties under pressure tuning. It is also unclear how structural change affects their excitonic features, which govern the optoelectronic properties of the halide perovskites. Herein, we report significantly enhanced photocurrents in the all-inorganic 2D perovskite Cs2PbI2Cl2, achieving over 3 orders of magnitude increase at the industrially achievable level of 2 GPa in comparison with its initial photocurrent. Lattice compression effectively regulates the excitonic features of Cs2PbI2Cl2, reducing the exciton binding energy considerably from 133 meV at ambient conditions to 78 meV at 2.1 GPa. Impressively, such a reduced exciton binding energy of 2D Cs2PbI2Cl2 is comparable to the values of typical 3D perovskites (MAPbBr3 and MAPbI3), facilitating the dissociating of excitons into free carriers and enhancing the photocurrent. Further pressurization leads to a layer-sliding-induced phase transition and an anomalous negative linear compression, which has not been observed so far in other halide perovskites. Our findings reveal the dramatically enhanced photocurrents in the 2D halide perovskite by regulating its excitonic features and, more broadly, provide new insights into materials design toward extraordinary properties.

Original languageEnglish (US)
Pages (from-to)2545-2551
Number of pages7
JournalJournal of the American Chemical Society
Volume143
Issue number6
DOIs
StatePublished - Feb 17 2021

Funding

This work was supported by the National Nature Science Foundation of China (NSFC) (Grants U1930401, 51527801, and 17N1051-0213). J.L. was supported by the National Natural Science Foundation of China (Grant 91433205), Tsinghua University Initiative Scientific Research Program. Q.H was supported by a XPLORE Award. At Northwestern work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Grant SC0012541 (compound synthesis and characterization). GeoSoilEnviroCARS was supported by the National Science Foundation - Earth Sciences (EAR-1634415), Department of Energy GeoSciences (DE-FG02–94ER14466), and partially by COMPRES under NSF Cooperative Agreement EAR-1606856. Use of the GSECARS Raman Lab System was supported by the NSF MRI Proposal (EAR-1531583). The in situ high-pressure powder XRD, single-crystal XRD, and Raman measurements were performed at GeoSoilEnviroCARS (The University of Chicago), Advanced Photon Source (APS), Argonne National Laboratory (ANL). This research used resources of APS, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by ANL under Contract DE-AC02-06CH11357. The authors appreciate the language editing by Freyja O’Toole.

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry

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