CsPbI 3 QDs are promising candidates for next-generation displays due to their excellent optoelectronic properties. However, achieving Rec.2020-standard pure-red emission with high efficiency and stability has proven difficult. While EA⁺incorporation can modulate the bandgap through lattice distortion, conventional EA⁺precursors typically decompose under the high temperatures required for QD synthesis.
Researchers from Zhejiang University of Technology have developed an innovative high-temperature hot-injection approach that enables stable EA + doping in CsPbI 3 QDs - a critical advancement for perovskite light-emitting diodes (PeLEDs) .
The team solved this problem by harnessing an acid–base equilibrium between ethylammonium carbonate and oleic acid, forming thermally robust ethylammonium oleate (EAOA) in situ . This robust precursor survives the harsh conditions of hot-injection synthesis, allowing effective EA⁺ incorporation without degradation. The resulting EA + -doped CsPbI 3 QDs exhibit lattice expansion, reduced defect densities, and near-unity photoluminescence quantum yield.
Through precise control of EA⁺doping concentrations, the researchers achieved tunable emission across the critical 630-650 nm range with outstanding spectral stability under operational conditions. Devices fabricated with these QDs achieved a maximum external quantum efficiency (EQE) of 26.1%, significantly surpassing the performance of undoped counterparts (9.9%).
“This thermally stable EA + doping approach provides unprecedented precision in tailoring perovskite QD emission properties while simultaneously boosting device stability and efficiency,” said Prof. Jun Pan, who led this study. “It opens a pathway to high-performance pure-red PeLEDs for next-generation ultra-high-definition displays.”
The researchers believe this strategy can be extended to other perovskite compositions and emission ranges, paving the way for advanced optoelectronic devices with tailored properties.
Science Bulletin
Experimental study