Fast MoTe₂ Waveguide Photodetector with High Sensitivity at Telecommunication Wavelengths

Two-dimensional (2D) materials integrated with planar photonic elements enable a new class of electro-optical components and hold much promise for a novel 2D material integrated circuit technology. Here, we present a few-layer MoTe₂ waveguide photodetector that is operable across the entire O-band of the near-infrared optical telecommunication spectral range. The device is realized in a two-terminal in-plane electrode configuration without applying external gating. It features a competitive photoresponsivity of 23 mA/W as well as a low dark current, both of which lead to a highly sensitive photodetection with a large dynamic range. Moreover, the design of the photodetector exhibits a fast photoresponse with a bandwidth approaching 1 GHz, outperforming prior TMDC-based photodetectors. Optical data experiments proved the operation of our device at data rates of 1 Gbit/s, revealing the applicability of integrating 2D materials for practical optical data communication applications.