TY - JOUR
T1 - Effects of Quantum and Dielectric Confinement on the Emission of Cs-Pb-Br Composites
AU - Caicedo-Dávila, S
AU - Caprioglio, P
AU - Lehmann, F
AU - Levcenco, S
AU - Stolterfoht, M
AU - Neher, D
AU - Kronik, L
AU - Abou-Ras, D
N1 - S.C.D. and D.A. are grateful for the financial support from the Helmholtz International Research School HI-SCORE (HIRS-0008). S.C.D. particularly thanks Prof. Dan Oron, Dr. Ayala Cohen, and Dr. Anna Hirsch (Weizmann Institute of Science) for their support and valuable discussions on the optical model, as well as the DFPT calculations and analysis. M.S. further acknowledges the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project number 423749265 – SPP 2196 (SURPRISE), as well the Heisenberg program – project number 498155101 for funding. L.K. thanks the Minerva Centre for Self-Repairing Systems for Energy & Sustainability, the Aryeh and Mintzi Katzman Professorial Chair, and the Helen and Martin Kimmel Award for Innovative Investigation, for their support.
PY - 2023/11/9
Y1 - 2023/11/9
N2 - The halide perovskite CsPbBr3 belongs to the Cs-Pb-Br material system, which features two additional thermodynamically stable ternary phases, Cs4PbBr6 and CsPb2Br5. The coexistence of these phases and their reportedly similar photoluminescence (PL) have resulted in a debate on the nature of the emission in these systems. Herein, optical and microscopic characterizations are combined with an effective mass, correlated electron–hole model of excitons in confined systems, to investigate the emission properties of the ternary phases in the Cs-Pb-Br system. It is found that all Cs-Pb-Br phases exhibit green emission and the non-perovskite phases exhibit PL quantum yields orders of magnitude larger than CsPbBr3. In particular, blue- and red-shifted emission for the Cs- and Pb-rich phases, respectively, are measured, stemming from embedded CsPbBr3 nanocrystals (NCs). This model reveals that the difference in emission shift is caused by the combined effects of NC size and different band mismatch. Furthermore, the importance of including the dielectric mismatch in the calculation of the emission energy for Cs-Pb-Br composites is demonstrated. The results explain the reportedly limited blue shift in CsPbBr3@Cs4PbBr6 composites and rationalize some of its differences with CsPb2Br5.
AB - The halide perovskite CsPbBr3 belongs to the Cs-Pb-Br material system, which features two additional thermodynamically stable ternary phases, Cs4PbBr6 and CsPb2Br5. The coexistence of these phases and their reportedly similar photoluminescence (PL) have resulted in a debate on the nature of the emission in these systems. Herein, optical and microscopic characterizations are combined with an effective mass, correlated electron–hole model of excitons in confined systems, to investigate the emission properties of the ternary phases in the Cs-Pb-Br system. It is found that all Cs-Pb-Br phases exhibit green emission and the non-perovskite phases exhibit PL quantum yields orders of magnitude larger than CsPbBr3. In particular, blue- and red-shifted emission for the Cs- and Pb-rich phases, respectively, are measured, stemming from embedded CsPbBr3 nanocrystals (NCs). This model reveals that the difference in emission shift is caused by the combined effects of NC size and different band mismatch. Furthermore, the importance of including the dielectric mismatch in the calculation of the emission energy for Cs-Pb-Br composites is demonstrated. The results explain the reportedly limited blue shift in CsPbBr3@Cs4PbBr6 composites and rationalize some of its differences with CsPb2Br5.
UR - http://www.scopus.com/inward/record.url?scp=85164482411&partnerID=8YFLogxK
U2 - 10.1002/adfm.202305240
DO - 10.1002/adfm.202305240
M3 - مقالة
SN - 1616-301X
VL - 33
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 46
M1 - 2305240
ER -