Waveguide-integrated ultra-stable perovskite single-crystal photodetector

Notwithstanding the exceptional photodetection capabilities of the laterally-structured perovskite single-crystal sheet(SCS), attributed to its notably lengthy carrier diffusion length and reduced defect density, operating the device within free space and exposing the SCS to the environment present obstacles in attaining on-chip integration and long-term stability.To overcome these challenges, this study proposes the introduction of a waveguide(WG) structure methodology, and selects the silicon WG(SWG) core and the polymer polymethyl methacrylate(PMMA) WG(PWG) fiber as materials. Furthermore, it integrates these two WG structures with the laterally-structured SCS photodetector into WG-SCS devices, enabling photodetection under near-field excitation of the WG. Significantly, the WG-SCS device encapsulated with silicone sealant demonstrates exceedingly high stability, with no degradation in performance after being exposed to light and water stimuli for1000 h. This study demonstrates the viability of on-chip integration of lateral-structured SCS photodetectors by means of introducing WG structures and investigates the technical facets of the device's long-term environmental stability. The results are expected to exert a crucial role in device integration in future applications such as optical communication, quantum photonics, and biochemical sensing.