Enhanced broadband photoresponse of a self-powered photodetector based on vertically grown SnS layers via the pyro-phototronic effect.

Here, we demonstrate the broadband photoresponse from ultraviolet (365 nm) to near-infrared (850 nm) wavelengths from a photodetector based on vertically grown SnS layers. Particularly, the photoinduced current density of the device increased from 100 to 470 μA cm-2 with a wavelength of 760 nm and an intensity of 7 mW cm-2 by utilizing the pyro-phototronic potential. In addition, the photodetector demonstrated ultrafast response rates of ∼12 μs for the rise and ∼55 μs for the decay times over the studied range. Moreover, a good photoresponsivity of 13 mA W-1 and a high photodetectivity of 3 × 1014 Jones at a wavelength of 760 nm with an intensity of 7 mW cm-2 were measured, representing enhancements of 340% and 3960%, respectively, with the pyroelectric potential. This excellent broadband performance was attributed to the photon-induced pyroelectric effect in the vertically grown SnS layers, which also modulated the optoelectronic processes. This novel approach will open a new avenue to design a broadband ultrafast device for advanced optoelectronics.