Fabrication of a high performance ZnIn2S4/Si heterostructure photodetector array for weak signal detection

Abstract

Owing to their exciting electronic and optical attributes, layered materials have attracted great interest in the field of next-generation photodetectors. However, owing to their large dark current, low detectivity and small signal-to-noise ratio, the performance of photodetectors based merely on layered materials is unsatisfactory for use in weak signal detection. Integrating layered materials with mature silicon (Si) technology offers a feasible scenario to overcome these drawbacks. Herein, we report the facile synthesis of layered ZnIn₂S₄ nanosheets and the construction of a ZnIn₂S₄/Si heterostructure photodetector array for weak signal detection. Owing to the interfacial charge transfer, which significantly suppresses the dark current and accelerates the separation of the photoexcited electron–hole pairs, the fabricated ZnIn₂S₄/Si photodetector array presents an ultralow dark current (18 pA), superior signal-to-noise ratio (11 572), stable photoswitching and high detectivity (2 × 10¹² Jones). Notably, the heterostructure device exhibits an outstanding weak signal detection capability, which has been successfully demonstrated using the detection of weak light sources including a cell phone screen, flashlight and lighter. These results demonstrate that the synergetic effect of layered materials and mature semiconductor technology shows great potential for application in next-generation optoelectronics.