Photoexcited Ultraviolet-to-Infrared (II) Pyroelectricity in a 2D Ferroelectric Perovskite Driving Broadband Self-Powered Photoactivities

摘要

Photoexcited pyroelectricity in ferroelectrics allows the direct conversion oflight radiation into electric signal without external power source, thus pavingan avenue to promote optoelectronic device performances. However, it isurgently demanded to exploit new ferroelectrics with this attribute coveringultraviolet (UV)-to-infrared (IR) region for self-powered photodetection. Herein,broadband light-induced pyroelectric effects in a new 2D perovskite-typeferroelectric, (BBA)2(EA)2Pb3Br10 (1; BBA = p-bromobenzylammonium, EA= ethylammonium), showing a high Curie temperature of 425 K and notablepyroelectric coefficient (≈5.4 × 10~(?3) μC cm~(?2) K~(?1)) is presented. Especially,photo-induced change of its electric polarization leads to ultraviolet-to-infraredpyroelectricity in a wide spectral region (377–1950 nm). Broadband photoactivitiesactualized by this property break the limitation of its optical bandgap.Thus, single-crystal detectors of 1 are sensitive to UV-to-IR light with a smalltemperature fluctuation of 0.3 K, exhibiting a high transient responsivity upto ≈0.28 mA W~(?1) and specific detectivity of 1.31 × 10~(10) Jones under zero bias(at 405 nm); such figure-of-merits are beyond than those self-powered photodetectorsusing oxide ferroelectrics. It is anticipated that the findings of lightinducedpyroelectricity afford a feasible strategy to assemble newly-conceptualsmart photoelectric devices, such as self-powered broadband detectors.