Exploring the Origin of Phase-Transformation Kinetics of CsPbI3 Perovskite Nanocrystals Based on Activation Energy Measurements

Cheng Chieh Lin, Shao Ku Huang, Chung En Hsu, Yu Chen Huang, Chuan Yu Wei, Cheng Yen Wen, Shao Sian Li, Chun Wei Chen, Chia Chun Chen

Research output: Contribution to journalArticle

Abstract

Perovskite α-CsPbI3 nanocrystals (NCs) with a high fluorescence quantum yield (QY) typically undergo a rapid phase transformation to a low-QY δ-CsPbI3 phase, thus limiting their optoelectronic applications. In this study, organic molecule hexamethyldisilathiane (HMS) is used as a unique surfactant to greatly enhance the stability of the cubic phase of CsPbI3 NCs (HMS-CsPbI3) under ambient conditions. The reaction kinetics of the phase transformation of CsPbI3 NCs are systemically investigated through in situ photoluminescence (PL), X-ray diffraction, and transmission electron microscope (TEM) measurements under moisture. The activation energy of HMS-CsPbI3 NCs is found to be 14 times larger than that of CsPbI3 NCs capped by olyelamine (OLA-CsPbI3 NCs). According to density functional theory calculations, the bonding between HMS and CsPbI3 NCs is stronger than that between OLA and CsPbI3 NCs, preventing the subsequent phase transformation. Our study presents a clear pathway for achieving highly stable CsPbI3 NCs for future applications.

Original languageEnglish
Pages (from-to)3287-3293
Number of pages7
JournalThe journal of physical chemistry letters
Volume11
Issue number9
DOIs
Publication statusPublished - 2020 May 7

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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