Broadband yellow light emitting performance based on zero-dimensional hybrid lead bromide trimers

Abstract

Low-dimensional hybrid lead halides have emerged as new-generation optoelectronic materials due to their compelling photoluminescence properties, and it is significant to explore new type of hybrid halides to diversify the photophysical performances. Herein, by using different kinds of organic cations as structural decoration strategies, we designed two new lead bromides, namely [MeBAPIm]₂Pb₃Br₁₂ (1) ([MeBAPIm] = 2-methyl-1,3-bis (3-aminopropyl) imidazolidine) and [PMDPTA]₂Pb₃Br₁₂ (2) (PMDPTA = pentamethyldipropene triamine), via a facile solvothermal reaction. Both the structures of these hybrids contain the same linear [Pb₃Br₁₂]⁶⁻ trimers based on face-shared [PbBr₆] octahedrons. Upon UV light excitation, compound 1 displays broadband yellow light emission covering the entire visible spectra with a promising photoluminescence quantum efficiency (PLQE) of 4.57%. The broadband light emission can be ascribed to the self-trapped excitons based on systematical characterizations including steady-state, temperature-dependent and time-resolved emission spectra. The white light emitting device can also be easily fabricated by coating the sample of compound 1 on a blue light chip.