Self‐Patterned CsPbBr3 Nanocrystal Based Plasmonic Hot‐Carrier Photodetector at Telecommunications Wavelengths

Abstract

AbstractExtending the photodetection range of lead halide perovskites into the near‐infrared telecommunications bands can not only enable a wide‐spectrum solar energy harvesting, but pave ways for important applications in biodetection, infrared imaging, and telecommunication. However, there is a lack of an effective means to apply lead halide perovskites for efficient photodetection covering a wide wavelength range in the telecommunications bands. Here, CsPbBr3 nanocrystal‐ (NC‐) based photodetector operating at wavelengths in the telecommunications bands via surface plasmon‐induced hot holes is demonstrated. The internal photoemission of the plasmon‐induced hot holes from plasmonic antennas into CsPbBr3 NCs enables a photocurrent at wavelengths around 1550 nm. Moreover, a solvent treatment is also performed on drop‐casted CsPbBr3 NC thin film leading to a nanoscale self‐patterning with a compact and uniform morphology. This treatment benefits the carrier transportation contributing to a detectable photoresponse and minimizes the optical scattering so that the CsPbBr3 NCs can be integrated into the plasmonic structure without damping its resonant feature. Consequently, the CsPbBr3 NC‐based plasmonic hot‐carrier device achieves polarization discrimination and wavelength‐selective photodetection without additional optical components.