3D-Heterojunction based on Embedded Perovskite Micro-sized Single Crystals for Fast Photomultiplier Photodetectors with Broad/narrowband Dual-mode.

A fast photomultiplier photodetector with a broad/narrowband dual mode was implemented using a new 3D heterostructure based on embedded perovskite micro-sized single crystals. Because the single-crystal size is smaller than the electrode size, the active layer can be divided into the perovskite microcrystalline part for charge transport and the polymer-embedded part for charge storage. This induces an additional radical interface in the 3D heterojunction structure, and allows the photogenerated built-in electric field in radical direction, especially when the energy levels between the perovskite and embedding polymer are similar. This type of heterojunction has a small radial capacitance that can effectively reduce carrier quenching and accelerate the carrier response. By controlling the applied bias direction, up to 300-1000% external quantum efficiency (EQE) and microsecond response can be achieved not only in the wide range of ultraviolet to visible light from 320 nm to 550 nm, but also in the narrow-band response with a full width at half minimum (FWHM) of 20 nm. This shows great potential for applications in integrated multifunctional photodetectors. This article is protected by copyright. All rights reserved.