【Member Papers】Professor Li Bingsheng's team from Northeast Normal University has implemented a silicon-based gallium oxide avalanche sun blind detector

      A high performance solar blind avalanche photodetector based on β-Ga₂O₃/AlN/n-Si an n-type semiconductor-barrier-n-type semiconductor (n/B/n) heterojunction has been realized. This achievement was reported by Bingsheng Li's group of wide band gap semiconductor materials and devices in the Key Laboratory of UV Light Emitting Materials and Technology, Ministry of Education, of Northeast Normal University and published in the journal of Materials Today Physics (2024,101474), DOI: 10.1016/j.mtphys.2024.101474) with a title of  “Solar blind avalanche photodetector based on a n-β-Ga₂O₃/n-Si heterojunction via an introduction of AlN buffer layer for interface lattice and band Engineering”.  

      This paper proposes a unipolar barrier β-Ga₂O₃/AlN/n-Si heterostructure as a solar-blind avalanche photodetector. Introducing the AlN buffer layer eliminates the native amorphous SiO_x layer, reduces lattice mismatch between β-Ga₂O₃ and Si, and improves the quality of β-Ga₂O₃ crystallization. Additionally, AlN barrier increases the conduction band shift of β-Ga₂O₃/Si, limits electron migration, reduces device dark current, and increases the reverse breakdown voltage. For the first time, a Si-based solar-blind UV avalanche detector was realized. At -55V bias, the detector has a detectivity of 2.9 × 10¹⁵ Jones, a UV-visible rejection ratio ( R_peak/R_400nm ) of 5.2 × 10⁵, a responsivity of 131.3 A/W, and a gain of 1.35×10³. This work provides an effective strategy for constructing a high-performance avalanche solar-blind-UV/visible/IR as a multi-color photodetector on one “chip” of a Si-based integrated circuit.

      This paper was completed by Chong Gao, a doctoral student from Northeast Normal University, as the first author, and Professor Bingsheng Li as the corresponding author. This work has supported by the funding from research programs such as the Ministry of Science and Technology's Major Research and Development Program for Transformational Technologies and the National Natural Science Foundation of China.

Fig. 1a) logarithmic I-V characteristic curve of the device under dark and UV light illumination, b) Spectral response of device at a -55 V bias (illustration is a logarithmic graph), and the c) responsivity and d) detectivity as functions of light intensity and applied bias.

Original link: https://doi.org/10.1016/j.mtphys.2024.101474