Improving Stability of Cesium Lead Iodide Perovskite Nanocrystals by Solution Surface Treatments

Dan Li; Chang-Song Chen; Yi-Hua Wu; Zhi-Gang Zhu; Wan Y Shih; Wei-Heng Shih

doi:10.1021/acsomega.0c01403

Improving Stability of Cesium Lead Iodide Perovskite Nanocrystals by Solution Surface Treatments

ACS Omega. 2020 Jul 13;5(29):18013-18020. doi: 10.1021/acsomega.0c01403. eCollection 2020 Jul 28.

Authors

Dan Li¹, Chang-Song Chen¹, Yi-Hua Wu^{1

2}, Zhi-Gang Zhu^{1

2}, Wan Y Shih³, Wei-Heng Shih⁴

Affiliations

¹ School of Environmental and Materials Engineering, College of Engineering, Shanghai Polytechnic University, Shanghai 201209, P. R. China.
² Research Center of Resource Recycling Science and Engineering, Shanghai Polytechnic University, Shanghai 201209, China.
³ School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania 19104, United States.
⁴ Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States.

Abstract

Cesium lead halide perovskite nanocrystals have a narrow emission peak tunable in the visible wavelength range with a high quantum yield. They hold great potential for optoelectronic applications such as light-emitting diodes or electronic displays. However, cesium lead iodide (CsPbI₃) is not stable under ambient conditions, limiting its applications. Here, we use a solution surface treatment approach to improve the photostability of CsPbI₃ suspensions in toluene. When a CsPbBr₃ precursor is used via the method of heterogeneous surface treatment, the photoluminescence (PL) intensity is enhanced but the PL only lasts 2 days. In contrast, when a CsPbI₃ precursor is used via the method of homogeneous surface treatment, not only the PL intensity of CsPbI₃ suspensions is enhanced but also the stability with the PL lasts for 11 days. It is likely that a better protection on the core CsPbI₃ by itself can be achieved because of better matching of the material structure and surface chemistry.