Nature Communications published research on September 12, 2026, detailing an H2S-mediated surface passivation strategy for metal halide perovskite quantum dots. Metal halide perovskite quantum dots are promising materials for developing low-cost and high-performance quantum dot-based light-emitting diodes, known as QLEDs. Perovskite quantum dot counterparts achieve peak EQE at low luminance and current density while exhibiting pronounced efficiency roll-off. This efficiency roll-off stems primarily from their ionic character and soft lattice.
Researchers developed an H2S-mediated surface passivation strategy to engineer a robust surface and ensure structural stability. Experimental measurements confirm lead-sulfur coordination alongside a reduction in oleylamine ligand density. Density functional theory calculations suggest that hydrogen sulfide dimers may interact with cesium-vacancy-related surface environments. This H2S-induced surface reconstruction creates a more robust surface coordination environment in cesium lead iodide quantum dots.
Device performance
LEDs incorporating the treated cesium lead iodide quantum dots possess an increased ion migration barrier, balanced charge injection, and suppressed Auger recombination. These combined improvements yield a peak external quantum efficiency of 30.71% at 52 milliamperes per square centimetre and 91.46 watts per steradian per square metre. The device maintains external quantum efficiencies of 18.59% at approximately 500 milliamperes per square centimetre and 21.15% at approximately 500 watts per steradian per square metre. Furthermore, the treated device achieves an operational half-lifetime of 104,587 hours.
Beamline experiments including Fourier transform infrared mapping, extended X-ray absorption fine structure, and grazing-incidence wide-angle X-ray scattering utilized beamlines BL06B, BL13SSW, and BL17B1 at the Shanghai Synchrotron Radiation Facility. Duo Zhang and Qiujuan Wang from HZWTECH provided help and discussions regarding the density functional theory calculations. Funding sources for the work include the National Natural Science Foundation of China, the Guangdong Basic and Applied Basic Research Foundation, the Shenzhen Science and Technology Program, the Natural Science Foundation of Wuhan, and the Science and Technology Program of Hubei Province.
