ZrTe3/PdSe2 vis-NIR detectors with Schottky barrier enhanced photovoltaic performance

Infrared photodetectors (PDs), particularly the near-infrared (NIR) PDs, are essential for applications in remote sensing, night vision, imaging, and so on. ZrTe3, a semimetallic transition metal trichalcogenide with zero bandgap, strong anisotropy, and enhanced conductivity, is emerging as a promising material for NIR PDs, provided that the noise can be effectively suppressed. The solution lies in constructing an appropriate barrier. PdSe2, a typical two-dimensional material with a layer-dependent bandgap is an excellent choice. By constructing a VdW heterostructure with ZrTe3 and six-layer PdSe2, a Schottky barrier is introduced to block photogenerated holes in ZrTe3, resulting in a five-order-of-magnitude reduction in dark current and an enhanced photovoltaic response. The ZrTe3/PbSe2 PD exhibits a self-powered photovoltaic response from 405 nm to 1.55 μm with a peak responsivity of 1.16 × 106 V/W, a rise/fall time of 58/66 μs, a 3 dB frequency of 4.6 kHz, and a linear polarization ratio of 3.15 at 808 nm. The strategy of introducing a Schottky barrier to semimetal-based PDs addresses the issues of high noise and biased working conditions, paving the way for high-performance semimetallic PDs in the NIR range.