Effect of dimensionality on the optical absorption properties of CsPbI3 perovskite nanocrystals

Autor(es)

Liu, Albert ^[1] ; Bonato, Luiz G. ^[2] ; Sessa, Francesco ^[1] ; Almeida, Diogo B. ^{[1, 3]} ; Isele, Erik ^[4] ; Nagamine, Gabriel ^[3] ; Zagonel, Luiz F. ^[3] ; Nogueira, Ana F. ^[2] ; Padilha, Lazaro A. ^[3] ; Cundiff, Steven T. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 - USA

^[2] Univ Estadual Campinas, Inst Quim, BR-13083859 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Inst Fis, BR-13083859 Campinas, SP - Brazil

^[4] Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 - USA

• Tipo de documento: Artigo Científico
• Fonte: Journal of Chemical Physics; v. 151, n. 19 NOV 21 2019.
• Citações Web of Science: 2

Resumo

The bandgaps of CsPbI3 perovskite nanocrystals are measured by absorption spectroscopy at cryogenic temperatures. Anomalous bandgap kshifts are observed in CsPbI3 nanocubes and nanoplatelets, which are modeled accurately by bandgap renormalization due to lattice vibrational modes. We find that decreasing dimensionality of the CsPbI3 lattice in nanoplatelets greatly reduces electron-phonon coupling, and dominant out-of-plane quantum confinement results in a homogeneously broadened absorption line shape down to cryogenic temperatures. An absorption tail forms at low-temperatures in CsPbI3 nanocubes, which we attribute to shallow defect states positioned near the valence band edge. Published under license by AIP Publishing. (AU)

• Processo FAPESP: 13/16911-2 - Espectroscopia avançada em novos nanomateriais
• Beneficiário: Lázaro Aurélio Padilha Junior
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores