Dual‐Phase Regulation for High‐Efficiency Perovskite Light‐Emitting Diodes

Abstract

Perovskite light‐emitting diodes (Pero‐LEDs) have attracted significant attention due to their high color purity and solution processing, presenting potential applications for next‐generation solid‐state lighting and displays. Continued materials development has shown that passivating non‐radiative defects can improve device performance. In theory, CsPbBr3&Cs4PbBr6 should be a model emitter for Pero‐LEDs, as its lattice matching provides ideal passivation and efficient exciton confinement. However, the low charge transport of Cs4PbBr6 has so far hindered device performance. Herein, a dual‐phase regulation method to grow a CsPbBr3&Cs4PbBr6 perovskite layer that enables efficient electrical injection is developed. This leads to the realization that Pero‐LEDs with a maximum EQE of 22.3% with a luminance of 10,050 cd m−2, and the devices show a T50 of 59 h at 130 cd m−2.

Ultra-stable, Solution-Processable CsPbBr3-SiO2 Nanospheres for Highly Efficient Color Conversion in Micro Light-Emitting Diodes

“…Compared with original CsPbBr 3 -SiO 2 NSs (PLQY = 37%), the sample produced via external K 2 CO 3 sintering showed PLQY = 51%, and internally K 2 CO 3 -sintered NSs featured a much higher PLQY = 87%. One possible cause of this further important benefit of internal K 2 CO 3 sintering is suggested by the XRD patterns reported in Figure S8, showing that the introduction of K 2 CO 3 induced the formation of a Cs 4 PbBr 6 phase, which has been previously demonstrated to bind to CsPbBr 3 and form a Type I junction that passivates surface defects and dramatically improves the PLQY. , This scenario is corroborated by the time decay PL curves reported in Figure e, showing that original CsPbBr 3 -SiO 2 NSs featured a slight multi-exponential decay dynamics with an effective lifetime (extracted as the time after which the PL intensity has dropped by a factor e ) of 4.7 ns and a longer-lived tail, commonly ascribed to regenerated band edge excitons by back-transfer from shallow traps. The addition of K 2 CO 3 turned the decay kinetics more single exponential and extended the lifetime to 6.2 ns for the externally K 2 CO 3 -sintered particles, up to 8.1 ns for the internally sintered NSs.…”

Efficient Perovskite Light-Emitting Diodes by Buried Interface Modification with Triphenylphosphine Oxide

“…The process flow diagram for preparing the TPPO buried interface modified perovskite film is displayed in Figure a. The NiMgLiO x HTL was prepared according to our previous report. , TPPO/dimethyl sulfoxide (DMSO) solution (60 μL) was dropped on the pre-heated NiMgLiO x substrate (100 °C), left to rest for 5 min to allow TPPO to adhere to the oxide surface, and spun at a speed of 2000 rpm for 30 s. The subsequent perovskite film preparations are detailed in the Experimental Section. We conducted Fourier transform infrared spectroscopy (FTIR) analysis to investigate the interaction between TPPO, NiMgLiO x , and perovskite film (Figure b).…”

Competing Energy Transfer-Modulated Dual Emission in Mn2+-Doped Cs2NaTbCl6 Rare-Earth Double Perovskites

“…Lead halide perovskites of ABX 3 (A = MA + , Cs + ; B = Pb 2+ , X = Cl – , Br – , I – ) have been widely studied due to their promising optoelectronic applications such as such as solar cells, − light-emitting diodes, − lasers, − X-ray detectors, − and scintillators. , However, lead-based halide perovskites are often unstable and easily hydrolyzed. − Meanwhile, the toxicity of lead limits their applications . Thus, it is urgent to develop alternative lead-free perovskites with photoelectric properties similar to those of lead-based perovskites.…”