Thermal Conductive Encapsulation Enables Stable High-Power Perovskite-Converted Light-Emitting Diodes

Significant progress has been achieved on perovskite nanocrystal (PNC)-converted light-emitting diodes (PcLEDs) with the development of surface encapsulations. However, achieving bright and long-living devices remains a challenge because the thermal isolation structure of the air barriers exacerbates heat accumulation inside PcLEDs. Here, we proposed a thermal conductive encapsulation for PNCs by embedding CsPbBr3 PNCs in layer-by-layer assembled boron nitride (BN) nanoplatelets through SiO2 crosslinking. This structure effectively suppresses the heat accumulation on PNCs and provides excellent air resistance, enabling the PNC-SiO2-BN composite to withstand 1000 h of photothermal annealing (under a 405 nm laser at 0.31 W cm(-2), 80 degrees C in air) without showing obvious degradation. Green- and white-light PcLEDs were fabricated via on-chip encapsulation of PNC-SiO2-BN. The PcLEDs achieved the milestone in long-term stability (half-life time > 1000 h) at a high power density of similar to 1.7 W cm(-2) and displayed extradentary stability at similar to 0.15 W cm(-2) with constant light intensity within 1000 h of sustained illumination. The success in making thermal conductive composites will expedite the application of PNCs in LED backlights and other optoelectronic devices.

Automated summary

This study proposed a new thermal conductive encapsulation technique for PNCs to improve the heat accumulation issue inside PcLEDs, effectively enhancing the long-term stability and durability of PcLEDs.