Surface Energy‐Mediated Self‐Catalyzed CsPbBr3 Nanowires for Phototransistors

Abstract

AbstractControllable self‐catalyzed growth of semiconductor nanowires (NWs) is of great importance, particularly to avoid impurities coming from foreign catalysts to deteriorate the NW properties. Although this catalyst‐free NW growth has many obvious advantages, there are very limited works focused on all‐inorganic CsPbBr3 perovskite NWs, which is one of the recent champion materials for electronics and optoelectronics. Here, a direct self‐catalyzed synthesis of freestanding CsPbBr3 NWs via vapor–liquid–solid growth mechanism by chemical vapor deposition is developed. Notably, mainipulation of the substrate surface roughness is the key enabling parameter for the self‐catalyzed NW growth here. It is revealed that the surface energy of substrates, modulated by its surface roughness, is found to effectively mediate the self‐catalytic growth of CsPbBr3 NWs. When configured into photodetectors, the intrinsic p‐type CsPbBr3 NWs exhibit good optoelectronic performance with a photoresponivity of ≈2000 A W−1, a detectivity of ≈2.57 × 1012 Jones, and a fast response down to 362 µs. All these results evidently indicate the technological potential of this self‐catalyzed synthesizing route for other high‐quality all‐inorganic perovskite NWs.