Broadband InSe/MoS Type-II Heterojunction Photodetector with Gate-Tunable Polarity Induced Near-Linear Wavelength-Dependent Photocurrent Peak.

Selectable polarity in van der Waals materials not only broadens the scope of design for electronic components but also opens new avenues for the development of advanced electronic, optoelectronic, and sensor devices. In this study, we fabricated vertically stacked InSe/MoS van der Waals type-II heterojunction photodetectors and conducted a systematic investigation of their photoelectrical properties. Our findings demonstrate the high performance of these photodetectors, characterized by effective suppression of charge recombination, the presence of both positive and negative photoconductivity under different incident light excitations, broad-spectrum detection ranging from 400 to 1064 nm, and remarkable responsivity and photodetectivity values of 10,200 A/W (-1430 A/W) and 3 × 10 cm Hz W (3.