Self-Powered Broadband Photodetectors Based on Si/SnS2 and Si/SnSe2 p–n Heterostructures

The escalating interest in 2D nanoflakes-based group-IVA metal chalcogenides is attributed to their noteworthy properties, such as high electron mobility, exceptional chemical stability, and applicability across diverse scientific disciplines such as sensing, energy storage applications, supercapacitors, and lithium-ion batteries. This study introduces an innovative self-powered photodetector based on 2D metal chalcogenide nanoflakes (SnS₂ and SnSe₂) formed into nanoflowers on a silicon substrate through the hydrothermal method. The amalgamation of the light-induced pyroelectric effect into the SnS₂ photodetector achieves impressive enhancement ratios of 353%, 425%, 351%, 662%, and 153% in photoresponsivity and detectivity compared to the photovoltaic effect at 365, 456, 532, 632, and 850 nm, respectively, at zero bias. The SnSe₂ photodetector achieved responsivity values of 14, 82, 36, 4, and 28 mA W⁻¹ at the corresponding wavelengths in self-powered mode. The SnSe₂ device exhibits superior photosensitivity of 30792%, 55692%, 28803%, 9678%, and 68587% at the corresponding wavelengths, under zero bias. In addition, the photocurrent response caused by the photovoltaic-pyroelectric effect is thoroughly defined, and the impacts of light wavelength, power intensity, and bias voltage are studied. This study presents a cutting-edge self-powered broadband photodetector utilizing pyroelectric materials and opens possibilities for designing high-performance, fast photodetectors based on the pyro-phototronic effect.