Degradation mechanisms of perovskite nanocrystals in color- converted InGaN micro-light-emitting diodes

The metal halide perovskite nanocrystals (NCs) have attracted much attention because of their excellent optical properties and potential for application in optoelectronic devices. However, their photo- and thermostability are still practical challenges and need further optimization. Here, we have studied the degradation behaviors of CsPbI3 NCs utilized as optical conversion layer in InGaN based blue micro-LEDs in situ. Furthermore, the effects of temperature and light irradiation on perovskite NCs were investigated respectively. The results indicate that both blue light irradiation and high temperature can cause the increased nonradiative recombination rate, resulting in the degradation of perovskite NCs and reduction of the photoluminescence quantum yield (PLQY). Especially in high-temperature condition, both the single-exciton nonradiative recombination rate and the biexciton nonradiative recombination rate are increased, causing the significant reduction of PLQY of perovskite NCs in high temperature environment than blue light irradiation. Our work provides a detailed insight about the correlation between the light irradiation and temperature consequences for CsPbI3 NCs and may help to pave the way toward optoelectronic device applications.

Automated summary

Metal halide perovskite nanocrystals have excellent optical properties and potential for optoelectronic device applications, but their photo- and thermostability still need optimization. This study investigates the degradation behaviors of CsPbI3 nanocrystals used as an optical conversion layer in blue micro-LEDs and shows that both blue light irradiation and high temperature can cause degradation and reduction of the photoluminescence quantum yield. The work provides insights into the correlation between light irradiation and temperature consequences for CsPbI3 nanocrystals, which is important for optoelectronic device applications.