Novel material design enables pure-red perovskite LEDs with record-breaking performance

A staff from the College of Science and Know-how of China (USTC) of the Chinese language Academy of Sciences (CAS) has resolved a essential problem in pure-red perovskite light-emitting diodes (PeLEDs) by figuring out and addressing the foundation reason behind effectivity loss at excessive brightness.

Revealed in Naturetheir examine introduces a novel materials design that allows record-breaking system efficiency, attaining a peak exterior quantum effectivity (EQE) of 24.2% and a most luminance of 24,600 cd m^-2—the brightest pure-red PeLED reported to this point.

Pure-red PeLEDs, essential for vivid shows and lighting, have lengthy confronted a trade-off between effectivity and brightness. Whereas 3D mixed-halide perovskites like CsPbI_3-xBr_x supply glorious cost transport, their effectivity plummets below excessive present as a result of unresolved provider leakage.

Utilizing a self-developed diagnostic tool referred to as electrically excited transient absorption (EETA) spectroscopy, the staff, led by Prof. Yao Hongbin, Fan Fengjia, Lin Yue, and Hu Wei, captured real-time provider dynamics in working units. They found that gap leakage into the electron transport layer—beforehand undetected as a result of a scarcity of in situ characterization strategies—was the first offender behind effectivity roll-off.

To deal with this, the researchers engineered a 3D intragrain heterostructure inside the perovskite emitter. This design embeds narrow-bandgap light-emitting areas inside a steady (PbX₆)^4- framework, separated by wide-bandgap limitations that confine carriers.

Key to the technique is the molecule p-Toluenesulfonyl-L-arginine (PTLA), which bonds strongly to the perovskite lattice by way of a number of functional groups (guanidino, carboxyl, amino, and sulfonyl).

PTLA expanded the lattice domestically, creating wide-bandgap phases with out disrupting structural continuity. Excessive-resolution TEM and ultrafast spectroscopy confirmed seamless provider switch between the heterostructure’s phases and suppressed gap leakage.

The optimized PeLEDs exhibited unprecedented efficiency: at 22,670 cd m^-2—almost 90% of peak brightness—the EQE remained at 10.5%, far surpassing earlier information. Stability exams revealed a half-lifetime of 127 hours at 100 cd m^-2with minimal spectral shift throughout operation.

The staff attributed this success to the heterostructure’s twin position: confining holes to the emitter whereas sustaining excessive provider mobility by an uninterrupted 3D lattice.

This work bridges a essential hole in perovskite optoelectronics, combining superior diagnostics with modern materials engineering. Reviewers hailed the examine as “a landmark in perovskite LED analysis,” emphasizing its methodological rigor and transformative outcomes.