Wavelength dependent UV-Vis photodetectors from SnS2 flakes

Abstract

2D layered materials have attracted increasing interest, owing to their unique properties and large potential for versatile applications. As one of the 2D layered semiconductors, tin disulfide (SnS₂) is rarely reported compared with other 2D materials like molybdenum disulfide (MoS₂). Herein, high quality SnS₂ flakes were grown by a facile and low-cost path, and photodetectors based on thin SnS₂ flakes were fabricated and characterized. These flakes are of high quality according to the results of XRD, Raman and TEM measurements, and present hexagonal and half-hexagonal forms with an average diameter of 100 μm. The devices based on these SnS₂ flakes showed wavelength dependent photo-responsive characteristics as the illuminating wavelength varied in the UV-Vis range (from 100 to 800 nm). They also showed excellent photo-responsive characteristics under monochromic illumination using three different wavelengths (533, 405 and 255 nm) with high photo-responsivity and high external quantum efficiency (EQE). The experimental results agree well with the first-principles calculated band structure and optical absorption coefficient curve.