Self‐Powered and Flexible Photodetector with High Polarization Sensitivity Based on MAPbBr₃–MAPbI₃ Microwire Lateral Heterojunction

Abstract

Assembling perovskites into heterojunctions is an effective approach to achieve high‐performance photodetectors. Compared with vertical heterojunctions, in lateral heterojunction‐based photodetectors, the reflection loss is reduced because the active layer is in direct contact with light resulting in higher performance and better stability. However, lateral perovskite–perovskite heterojunctions are difficult to achieve using solution methods because the first formed film is easily dissolved by the solvent of the second precursor. In this study, a two‐step imprinting method is developed to fabricate lateral MAPbI3–MAPbBr3 microwire heterojunctions and realize a high‐performance photodetector with a responsivity and detectivity of 1207 A W−1 and 2.78 × 1013 Jones, respectively. At 0 V bias, the device exhibits a responsivity of up to 233 A W−1, which is more than double the previously reported best results. The high‐quality heterojunction endows the photodetectors with ultra‐high polarization sensitivity (Imax/Imin = 8.2) and long‐term stability, retaining 88.2% of its initial performance even after being exposed to air for 391 d.

Chiral 2D/Quasi‐2D Perovskite Heterojunction Nanowire Arrays for High‐Performance Full‐Stokes Polarization Detection

“…The improved linear polarization sensitivity of the heterojunction device is owing to the built-in electric field at the junction. [48][49][50] When the linearly polarized light is parallel to the length direction of heterojunction NW, the carriers generated in the heterojunction have maximum momentum in the direction of the built-in electric field, which can efficiently separate the electron-hole pairs and reduce their recombination probability, thus leading to a pronounced I max . As the linear polarization gradually deviating from the direction of the built-in electric field until perpendicular, the momentum of the photogenerated carriers gradually decreases and reaches a minimum value.…”

Self-Powered Broadband Photodetectors Material Based on Co3O4–ZnO Heterojunction with Bottlebrush Nanostructure

“…In the past decades, we have witnessed the development of semiconductor materials which can be made into different nanostructures using various methods to meet the needs of low-cost and high-performance devices like photodetectors − and solar cells. , Photodetectors, especially broadband detectors, have attracted extensive research attention owing to their widespread applications in optical communication to military monitoring, multispectral detection, and environmental monitoring. − The main limitation facing these photodetectors is the need of an externally applied bias voltage to operation, which limits their applications in wireless environmental sensing, nanorobotics, portable personal electronics, and in situ medical therapy monitoring. − Therefore, to expand the application range and reduce the size and mass of photodetectors, self-powered photodetectors that are capable of self-biased-mode operation and broadband light absorption have received extensive research attention. ,− …”

High-Resolution In Situ Crystallization and Patterning of a CsPbBr3 Film via Femtosecond Laser Printing

“…However, film inhomogeneity caused by the coffee ring effect and limitations on ink viscosity hinder the further development of the technology for high-resolution patterning of perovskite . Li et al developed an in situ conformal nanoimprinting technology to control the size and location of perovskite crystals . The route offers a potential pathway to achieve high-precision patterning of perovskite but is inherently multistep and requires the fabrication of masks to develop new patterns .…”

“…9 Li et al developed an in situ conformal nanoimprinting technology to control the size and location of perovskite crystals. 10 The route offers a potential pathway to achieve highprecision patterning of perovskite but is inherently multistep and requires the fabrication of masks to develop new patterns. 11 Up to now, there has been an increasing need to develop an effective and facile patterning strategy that enables flexible fabrication of high-quality and high-precision patterned perovskite films.…”