Achieving Ultra-Stable, Near-Unity Photoluminescence Quantum Yield Under Extreme Humidity and High Electric Field for CsPbBr3 Nanocrystals Through the Surface Attachment of ZnO Nanoparticles

The successful optoelectronic applications of solution-processed CsPbBr3 nanocrystals (NCs) demand their long-term environmental stability under various ambient conditions. Despite their superior emission properties, solution-processed CsPbBr3 NCs suffer from structural and optical property degradation under various ambient conditions like humidity, moisture, and oxygen, a significant obstacle to utilizing their potential as optoelectronic devices. Structural degradation leads to the degradation of optical properties and, hence, efficiency degradation. Here, we report a simple room-temperature method of attaching ZnO nanoparticles (NPs) on the surface of CsPbBr3 NCs to protect against environmental factors, mainly humidity-induced degradation. CsPbBr3 NCs passivated with ZnO NPs show near-unity photoluminescence quantum yield with excellent stability under humidity > 85% for over two months. The ZnO surface attachment leads to higher charge carrier mobility through remote trap passivation. Moreover, the passivated CsPbBr3 NCs show excellent emission stability under a high electric field, indicating their appropriate application in light-emitting devices.