Highly efficient white-light emission in a polar two-dimensional hybrid perovskite

Abstract

Broadband white-light emission was realized in a polar two-dimensional hybrid perovskite, (2meptH2)PbBr4 (2mept = 2-methyl-1,5-diaminopentane). The white-light emission originates from self-trapped excitons owing to the distortion-induced polar structure. Notably, it exhibits a high photoluminescence quantum efficiency of 3.37% and an ultrahigh colour rendering index of 91.

White light emission in low-dimensional perovskites

“…2b). 32,[50][51][52] Recently, M. D. Smith et al rationalized the structure/optical properties relationship by examining the ratio between the intensities of the broad emission (I BE ) and the narrow emission (I NE ) in a set of eight <100>-oriented bromide perovskites. 47,53 Within this dataset, it was found that the relative intensity of the broad emission (given by the ratio I BE /I NE ) increases with the increase of out-of-plane distortion of the Pb-(µ-Br)-Pb angle, with the exception of (CEA) 2 PbBr 4 (CEA = cyclohexylammonium) which shows room temperature broadband emission despite the absence of out-of-plane tilt.…”

Simple fabrication of layered halide perovskite platelets and enhanced photoluminescence from mechanically exfoliated flakes

“…[6][7][8][9] Among the low-dimensional perovskites, two-dimensional (2D) layered crystals have been the focus of several studies, given their bright emission, possible white fluorescence, and, in particular, their environmental stability. [10][11][12][13][14] Moreover, 2D perovskites have exciton binding energies of about 300 meV that are larger than those of their 3D counterparts, which is advantageous for potential applications in the field of optoelectronics. [15][16][17] Layered perovskite crystals are made of a sequence of inorganic layers formed by corner-sharing [PbX 6 ] 4− octahedra, which are chemically passivated by organic moieties with smaller dielectric constant and higher exciton binding energies than the inorganic layer.…”

From Distortion to Disconnection: Linear Alkyl Diammonium Cations Tune Structure and Photoluminescence of Lead Bromide Perovskites

“…Stable 2D organic–inorganic hybrid halide perovskites with white emissions and high color tunability which are also low‐cost and easy‐process are promising single‐component phosphor material for light emitting diodes (LEDs). [ 22–26 ] As the 2D organic–inorganic hybrid perovskites have achieved tunable narrow emission recently, broadband white light emissions are observed in a few (110)‐oriented organic–inorganic hybrid 2D corrugated perovskites. Such as ( N ‐MEDA)[PbBr 4 ] ( N ‐MEDA = N 1 ‐methylethane‐1,2‐diammonium) [ 22 ] and α‐(DMEN)PbBr 4 (DMEN = 2(dimethylamino)ethylammonium) [ 24 ] are typical corrugated (110)‐oriented 2D perovskites for warm white‐light emission.…”