A Graphene/h-BN/Bi₂O₂Se Metal-Insulator-Semiconductor Tunneling Photodetector

KunHung Pan^1*

¹Institute of Photonics Technology, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:KunHung Pan, email:Eddy891030@gmail.com

The emerging 2D material Bi₂O₂Se has demonstrated great potential in broadband photodetection due to its high electron mobility, excellent air stability, and suitable near-infrared (NIR) bandgap (≈ 0.85 eV). However, current Bi₂O₂Se-based phototransistors commonly suffer from high dark current, which severely limits the device on/off ratio and detection performance. To address this challenge, this study designs and fabricates a vertical Metal-Insulator-Semiconductor (MIS) tunneling heterostructure photodetector based on Graphene/h-BN/Bi₂O₂Se. In this structure, the h-BN insulating layer serves as a tunneling barrier, effectively suppressing the dark current while allowing photogenerated carriers to tunnel under bias, generating a photocurrent. The device's response range covers the visible to near-infrared (NIR) spectrum. Furthermore, we measured the Fourier-transform infrared (FTIR) spectrum of the Bi₂O₂Se material, confirming its significant absorption capability in the NIR band, which aligns with its theoretical bandgap. The proposed MIS tunneling architecture offers a novel design approach for developing low-dark-current, high-sensitivity Bi₂O₂Se photodetectors.

Keywords: Bi2O2Se, Photodetector, Tunneling, Van der Waals Heterostructure