Visible to Near-Infrared Light Detectors Based on Au/SnS/Ag Schottky Structure With Ultrahigh Responsivity and Fast Response

In this work, light detectors utilizing p-type tin monosulfide (p-SnS) few layers with an Au/SnS/Ag Schottky structure are demonstrated. These detectors exhibit broad-spectrum light detection capabilities spanning the visible to near-infrared (NIR) wavelength range. Notably, under NIR 850 nm illumination, the detectors exhibit exceptional photodetection performance with an ultrahigh responsivity of up to 1652.87 $\text{A}\cdot \text{W}^{-{1}}$ , an extremely specific detectivity of $8.05\times 10^{{12}}$ cm $\cdot $ Hz $^{\text {1/{2}}}\cdot \text{W}^{-{1}}$ , and a rapid response time of approximately 6.5 ms. These characteristics surpass those of most 2-D materials-based detectors and even outperform commercial InGaAs (Hamamatsu, InGaAs G8370-85) and Silicon (Hamamatsu, Si S9119-01) detectors. The remarkable photoresponse is attributed to the SnS/Ag Schottky structure, which facilitates the separation of excited electron–hole pairs. Our findings suggest a promising route for developing high-performance optoelectronics based on p-SnS.