High-performance Near-infrared Photodetector Based on Surface Periodic Structure of the Perovskite Single-crystal Sheet

In this paper, millimeter-sized CH3NH3PbI3(MAPbI(3)) single-crystal sheets(SCSs) were synthesized using the spatial confinement method, and the periodic structures were fabricated on the SCS surface by focused ion beam(FIB) etching technology, enabling the resonance absorption peak to be located in the near-infrared band. Based on this active layer, a longitudinal-structured photodetector(PD) was constructed. The detection capability of such device in the two-photon near-infrared light(1064 nm) was significantly enhanced by two orders of magnitude compared to the device based on pristine MAPbI(3) SCSs. Specifically, the PD responsivity can reach 0.6 A/W, the on-off ratio can reach 1.7x10(4)(the dynamic linear region is approximately 84.6 dB), the external quantum efficiency can reach 58.2%, and the specific detectivity is about 6.3x10(12) Jones(1 Jones=1 cm<middle dot>Hz(1/2)<middle dot>W-1). The result demonstrates the high feasibility of FIB etching for processing the periodic structure on the surface of MAPbI(3) SCSs, which will greatly contribute to the design and fabrication of high-performance near-infrared photodetectors based on perovskite single-crystal sheet.