Abstract

Since the first generation of graphene research, extensive research effort has been paid to two-dimensional (2D) layered materials owing to the interesting physics and various applications in nanoelectronics, optoelectronics, and energy conversion.[1,2] Especially, the high-sensitive photodetectors with broad response have been demonstrated based on the novel 2D materials, such as graphene, transition metal dichalcogenides and black phosphorus.[3] As a new member of 2D material family, metal monochalcogenides (e.g., GeS and GeSe) have attracted much interests for the highly sensitive photodetector applications. The p-type semiconductor 2D GeS with an orthorhombic structure has close direct and indirect optical transitions with small energy difference around 1.66 eV. Our previous report showed that the GeS exhibits strong light absorption in a broad range from visible to near-infrared spectral regions, which indicates that the GeS would work as a high-sensitive photodetector.[4]

© 2016 Japan Society of Applied Physics, Optical Society of America