Ultrasensitive MoS2 photodetector by serial nano-bridge multi-heterojunction

The recent reports of various photodetectors based on molybdenum disulfide (MoS2) field effect transistors showed that it was difficult to obtain optoelectronic performances in the broad detection range [visible–infrared (IR)] applicable to various fields. Here, by forming a mono-/multi-layer nano-bridge multi-heterojunction structure (more than > 300 junctions with 25 nm intervals) through the selective layer control of multi-layer MoS2, a photodetector with ultrasensitive optoelectronic performances in a broad spectral range (photoresponsivity of 2.67 × 106 A/W at λ = 520 nm and 1.65 × 104 A/W at λ = 1064 nm) superior to the previously reported MoS2-based photodetectors could be successfully fabricated. The nano-bridge multi-heterojunction is believed to be an important device technology that can be applied to broadband light sensing, highly sensitive fluorescence imaging, ultrasensitive biomedical diagnostics, and ultrafast optoelectronic integrated circuits through the formation of a nanoscale serial multi-heterojunction, just by adding a selective layer control process.
Fabrication of photodetector devices by selective etching of 2D materials can enable broadband detection. Here, the authors design mono- and multi-layer nano-bridge multi-heterojunction photodetectors based on MoS2 with high responsivities of 2.67 × 106 A/W and 1.65 × 104 A/W in the visible–infrared wavelength range and fast photoresponse.