Transition‐Metal‐Carbide (Mo₂C) Multiperiod Gratings for Realization of High‐Sensitivity and Broad‐Spectrum Photodetection

Abstract

Abstract A novel hybrid phototransistor consisting of molybdenum carbide (Mo 2 C) and molybdenum disulfide (MoS 2 ) is proposed. By exploiting the interface properties of MoS 2 and Mo 2 C, a highly sensitive and broad‐spectral response photodetector is fabricated. The underlying mechanism of the enhanced performance is the efficient hot carrier injection from Mo 2 C to MoS 2 . The strong coupling of MoS 2 and Mo 2 C at the interface provides the significantly low Schottky barrier height (≈70 meV), which gives rise to the significantly efficient hot carrier transfer from Mo 2 C to MoS 2 . The grating of metallic Mo 2 C produces plasmonic resonance, which provides hot carriers to the MoS 2 channel. By adjusting the grating period of Mo 2 C (400–1000 nm), the optimal photoresponse of light can be controlled, from visible to NIR. By integrating various Mo 2 C multigrating periods (400–1000 nm) with MoS 2 , a novel photodetector is demonstrated with high responsivity (R > 10 3 A W −1 ) and light‐to‐dark current ratio (>10 2 ) over a broad spectral range (405–1310 nm). The proposed novel hybrid photodetector, 2D semiconductors with multigrating 2D metallic stripes, exhibits high sensitivity and broad spectral detection of light and can overcome the inherent weakness of conventional 2D photodetectors, paving the way forward for next‐generation photoelectric devices.