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Modulation of Electronic States of Hybrid Lead Halide Perovskite Embedded in Organic Matrix
Author(s) -
Singh Shivam,
Dey Amrita,
Kolay Santa,
Kabra Dinesh
Publication year - 2020
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201900894
Subject(s) - crystallite , photoluminescence , perovskite (structure) , blueshift , materials science , bohr radius , quantum dot , nanotechnology , chemistry , crystallography , optoelectronics
The modulation of electronic states of MAPbX 3 perovskite nanocrystals (PNCs) (MA = CH 3 NH 3 + and X = Br − and I − ) is presented as a function of crystallite size in organic semiconductor matrix forming a type‐I heterostructure with bulk perovskites. Organic semiconductor molecule (4,4′‐bis[9‐dicarbazolyl]‐2,2′‐biphenyl [CBP] and bathocuproine [BCP]) precursors are mixed in different volumetric ratios with MAPbX 3 perovskite precursors to prepare thin films. This results into an easy growth of MAPbX 3 PNCs of tunable sizes from ≈110 to ≈10 nm in organic semiconductor matrix. A blue shift is observed in the photoluminescence peak (PL max ) energy over a range of ≈200 meV for MAPbI 3 PNCs embedded in the BCP matrix. However, PL max energy tunes over ≈32 meV only with a similar volumetric concentration in the case of MAPbBr 3 PNCs in the same BCP matrix. Moreover, the PL blue shift is even lower in the case of CBP matrix in comparison with BCP matrix for both the perovskites. This discrepancy could be resolved by determining the resultant crystallite size using X‐ray diffraction studies and the Debye–Scherrer formula. Results about blue shift in the PL peak can be explained using the classic particle‐in‐a‐box versus excitonic Bohr radius model under a weak confinement regime.