MAPbBr3 single crystal based metal-semiconductor-metal photodetector enhanced by localized surface plasmon

Abstract

Hybrid organic-inorganic lead halide perovskites (HOIPs) have appealed to researchers on account of excellent optoelectronic properties. Compared with films which possess grain boundaries, HOIPs single crystals with fewer defects behave excellent transport and recombination performances. In the family of HOIPs, single crystals of MAPbX3 (MA = CH3NH3+, X = Cl, Br or I) are recognized as the most competitive candidates for optoelectronic applications. However, the photodetectors based on MAPbX3 have difficulties in detecting weak signals for lacking of gains without structure optimizations and extra energy transfer channels. In this study, taking advantage of MAPbBr3 single crystal (100) facets, planar metal-semiconductor-metal (MSM) photodetectors were fabricated with Au zigzag electrodes and modified Au nanoparticles (NPs) to realize localized Au surface plasmons (SPs). Compared to device without Au NPs, 2 times enhancement of photocurrent and responsivity have been achieved under 630 nm photon irradiation and 5 V bias. Furthermore, the surface metal structures can inhibit ionic migration to a certain extent. Potential mechanisms of the enhancements and suppressions are discussed in details to reveal the applications of this technique.