Growth of quasi-1D PtSe2 semimetallic nanowire for high-performance bi-directional photodetection

• • First successful synthesis of quasi-1D PtSe2 via carrier-gas-assisted CVD, achieving highly oriented crystalline growth along the (110) plane with exceptional thermodynamic stability, enabling scalable production of 1D TMDC structures. • • Quasi-1D multilayer PtSe2 exhibits semimetallic behavior, while 2D few-layer PtSe2 is p-type semiconductor, demonstrating dimension-dependent electronic phase transition critical for device design. • • At 1550 nm, quasi-1D PtSe2 photodetector achieves a maximum negative photoresponse of 194.2 A/W, outperforming the 97.0 A/W positive response of 2D PtSe2, enabling bi-directional photodetection with high sensitivity. • • Temperature-dependent measurements confirm the negative photoresponse originates from a defect-assisted photogating effect, with strength significantly dependent on temperature under high-power illumination, providing a tunable mechanism for infrared detection.