A MoS2/BAs heterojunction as photodetector

With high thermal conductivity and carrier mobility, cubic boron arsenide (BAs) shows huge potential in high-power and high-speed optoelectronic devices. However, researches about BAs-based junction device are rare by now due to preparation difficulties. Herein, by mechanical exfoliation of molybdenum disulfide (MoS2) flake and planar transfer technology to a BAs crystalline substrate, a MoS2/BAs p-n junction was fabricated without considering the lattice matching problem. A self-driving optoelectronic performance obtained from the MoS2/BAs heterojunction with a rectification ratio of 3000 in ±3 V, a response speed of 0.25/0.58 ms and an Ion/Ioff ratio of 3 × 104 at zero bias. In addition, a rational interface thermal boundary conductance of 10.2 MW m−2 K−1 was measured between the exfoliated MoS2 flake and BAs crystal. Such behaviors reveal a feasibility of BAs as the substrate of mixed-dimensional heterostructures for more advanced semiconductor devices.