Built-In 3D-Heterojunction Optical Microcavity Based on an Embedded Microsize Single Crystal in Collaborative Dendritic Perovskite Microcrystals for Ultraviolet Narrowband Photodetectors

Abstract

A collaborative dendritic perovskite microcrystal with a built-in optical microcavity in the 3D-heterostructure device was synthesized to obtain ultraviolet narrowband detection by narrowing the double response edge. The two reflection oscillation modes of the four pyramid optical cavities constructed within perovskite microcrystals promote photogenerated charge carriers’ attachment to the crystal side along the light reflection trajectory. The radial capacitance unique to the 3D heterojunction in this device guides the recombination of long wavelength charges gathered on the crystal surface, thus eliminating long-wavelength photoresponse to obtain an ultraviolet narrowband. As a result of the simultaneous narrowing of the response from both sides, a specific narrowband ultraviolet response with a full width at half-maximum (fwhm) of less than 40 nm is obtained. The synergistic effect of three regions in the dendritic microcrystals is used to capture photons and transport and confine charges, breaking through the limitation of the responsivity of a single microcrystalline unit to the same level of response as large-area polycrystalline devices.