Single component Mn-doped perovskite-related CsPb₂Cl_xBr_5−x nanoplatelets with a record white light quantum yield of 49%: a new single layer color conversion material for light-emitting diodes

Abstract

Single component nanocrystals (NCs) with white fluorescence are promising single layer color conversion media for white light-emitting diodes (LED) because the undesirable changes of chromaticity coordinates for the mixture of blue, green and red emitting NCs can be avoided. However, their practical applications have been hindered by the relative low photoluminescence (PL) quantum yield (QY) for traditional semiconductor NCs. Though Mn-doped perovskite nanocube is a potential candidate, it has been unable to realize a white-light emission to date. In this work, the synthesis of Mn-doped 2D perovskite-related CsPbClBr nanoplatelets with a pure white emission from a single component is reported. Unlike Mn-doped perovskite nanocubes with insufficient energy transfer efficiency, the current reported Mn-doped 2D perovskite-related CsPbClBr nanoplatelets show a 10 times higher energy transfer efficiency from perovskite to Mn impurities at the required emission wavelengths (about 450 nm for perovskite emission and 580 nm for Mn emission). As a result, the Mn/perovskite dual emission intensity ratio surprisingly elevates from less than 0.25 in case of Mn-doped nanocubes to 0.99 in the current Mn-doped CsPbClBr nanoplatelets, giving rise to a pure white light emission with Commission Internationale de l'Eclairage (CIE) color coordinates of (0.35, 0.32). More importantly, the highest PL QY for Mn-doped perovskite-related CsPbClBr nanoplatelets is up to 49%, which is a new record for white-emitting nanocrystals with single component. These highly luminescent nanoplatelets can be blended with polystyrene (PS) without changing the white light emission but dramatically improving perovskite stability. The perovskite-PS composites are available not only as a good solution processable coating material for assembling LED, but also as a superior conversion material for achieving white light LED with a single conversion layer.

Introducing Cations (Zn2+, Sn2+ and Mg2+) and Anions(Cl−) to Tune Mn Photoluminescence Intensity of Doped Perovskite Nanocrystals(CsPbCl3)

“…By controlling the ratio of PNCs and PMMA, we can efficiently tune the Mn emission intensity of PNC‐PMMA films in the PL LEDs. The CIE1931 color coordination of final PL LED is (0.5135, 0.3963) and in the orange area, which is comparable with those reported ones ,…”

Large-area perovskite solar cells – a review of recent progress and issues

“…Meanwhile, organic-inorganic perovskites have a high optical absorption coefficient 4 and the diffusion lengths exceed 1 mm for electrons and holes. 5 So, organic-inorganic perovskite is an ideal absorber material for solar cells, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] photodetectors, [20][21][22] light-emitting diodes, [23][24][25][26] etc.…”

Metal halide perovskite nanocrystals and their applications in optoelectronic devices

“…), B site doping (with Mn 2+ , Ni 2+ , Sn 4+ , Ln 3+ , etc. ), surface engineering, matrix encapsulation, and postprocessing …”

“…), 256 B site doping (with Mn 2+ , Ni 2+ , Sn 4+ , Ln 3+ , etc. ), [257][258][259][260][261][262][263][264] surface engineering, 195,197 matrix encapsulation, 196,265 and postprocessing. 161,266,267 Coupled with lattice incompleteness, many defects are presented in these NCs, including Schottky defects (cation and anion vacancies), Frenkel defects (interstitial sites), inversion defects, and structural defects (grain boundary, interface, and lattice distortion caused by impurities).…”