Photocurrent response of type-II Dirac semimetal PtTe₂

Recently, topological semimetals have attracted extensive research interest in optoelectronics properties, especially in the area of high-performance photodetection for low-energy photons. Among various topological semimetals, the photocurrent response of type-II Dirac semimetals with tilted cones that breaks Lorentz invariance is seldom studied. In this work, we report the photocurrent response studies of a lateral field-effect device based on type-II Dirac semimetal PtTe2 over a broad wavelength range from 532 nm4 μm. A moderate responsivity of 34 μA W-1 is obtained at 633 nm without applying any external bias. Further excitation power and temperature-dependent measurements are performed to reveal the photocurrent response mechanism of PtTe2. The measurement results show clear anisotropic photocurrent response through polarization-dependent measurement and a response time of 34 μs can be extracted from chopping frequency-dependent measurement. We provide a comprehensive study of the photocurrent response of type-II Dirac semi-metallic PtTe2.