Direct CVD Growth of MoS₂ on GaN for 2D heterojunction Self-power Photodetector

Bor-Wei Liang^1*, Chun-Sheng Huang², Yann-Wen Lan¹

¹Department of Physics, National Taiwan Normal University, Taipei, Taiwan
²Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan

* Presenter:Bor-Wei Liang, email:charlie155155@hotmail.com

The self-powered photodetectors are highly desirable due to the vigorous development of communication technology. In this work, we demonstrate the self-powered photodetector fabricated by the direct chemical vapor deposition (CVD) growth of Molybdenum disulfide (MoS₂) on p-GaN/sapphire substrates. This MoS₂/GaN photodetector can well achieve a short response time (18.5/74.9 ms), high photo-responsivity (62.58 A/W), detectivity (2.67×10¹¹ Jones), and broadband detection (from UV to NIR). These excellent properties were attributed to low lattice mismatch between MoS₂ and GaN. This high-quality interface can provide an ideal pn heterojunction between MoS₂ and GaN and avoid the charge-trapping mechanism. Therefore, the built-in electric field in the pn junction can offer the fast and efficient electron-hole pair separation characteristic allowing the photodetector to obtain fast optical response rates and large photoelectric efficiencies. The direct CVD growth of MoS₂ photodetector is believed to be a potential candidate for the low power consumption electronics in the future.

Keywords: photodetectors, self-powered electronics, pn junction, broadband detection, MoS2/GaN heterostructure.