Hexamethyldisilazane-triggered room temperature synthesis of hydrophobic perovskite nanocrystals with enhanced stability for light-emitting diodes

A novel facile room-temperature, hexamethyldisilazane (HMDS)-mediated strategy is demonstrated for the synthesis of all-inorganic perovskite colloidal nanocrystals (NCs). As a unique reaction-triggering and morphology-directing agent, HMDS is introduced for the first time to trigger the room-temperature reaction for generating perovskite NCs with controlled morphology and optical properties. Particularly, the stability of the resulting NCs is greatly enhanced due to the surface modification by hydrophobic -CH3 groups from HMDS. The typical CsPbBr3 perovskite NCs films are highly stable without significant decrease in photoluminesence (PL) intensity after being exposed to 60% relative humidity for 720 h. Moreover, no noticeable change of phase and morphology occurs even after 100 days of exposure. The representative CsPbBr3 NCs are employed in a prototype white-light-emitting diodes (WLEDs) on 365 nm commercial GaN chip. The present strategy provides a facile and versatile route not only to control the morphology and optical properties of perovskites nanomaterials at room temperature but also enhance their stability, which will bring promising potential application for optoelectronics. (C) 2019 Elsevier Inc. All rights reserved.