Composition-Dependent Hot Carrier Relaxation Dynamics in Cesium Lead Halide (CsPbX3, X=Br and I) Perovskite Nanocrystals

Heejae Chung, Seok Il Jung, Hyo Jin Kim, Wonhee Cha, Eunji Sim, Dongho Kim, Weon Kyu Koh, Jiwon Kim

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Abstract

Cesium-based perovskite nanocrystals (NCs) have outstanding photophysical properties improving the performances of lighting devices. Fundamental studies on excitonic properties and hot-carrier dynamics in perovskite NCs further suggest that these materials show higher efficiencies compared to the bulk form of perovskites. However, the relaxation rates and pathways of hot-carriers are still being elucidated. By using ultrafast transient spectroscopy and calculating electronic band structures, we investigated the dependence of halide in Cs-based perovskite (CsPbX3 with X=Br, I, or their mixtures) NCs on the hot-carrier relaxation processes. All samples exhibit ultrafast (<0.6 ps) hot-carrier relaxation dynamics with following order: CsPbBr3 (310 fs)>CsPbBr1.5I1.5 (380 fs)>CsPbI3 NC (580 fs). These result accounts for a reduced light emission efficiency of CsPbI3 NC compared to CsPbBr3 NC.

Original languageEnglish
Pages (from-to)4160-4164
Number of pages5
JournalAngewandte Chemie - International Edition
Volume56
Issue number15
DOIs
Publication statusPublished - 2017 Jan 1

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All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)

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