Ultraviolet photodetector based on p+-Si/n-ZnO bilayer structure
Wenqing Song1, Rongping Yu1, Mengdi Chen1
1School of Intelligent Manufacturing and Mechanical Engineering, Hunan Institute of Technology, Hengyang, 421002, China.
Scientific Reports
|October 24, 2025
Summary
This study shows a new p+-Si/n-ZnO bilayer photodetector with faster speeds and better responsivity. Its unique structure improves ultraviolet (UV) light detection by shortening charge paths.
Area of Science:
- Materials Science
- Optoelectronics
- Semiconductor Physics
Background:
- Single-layer ZnO photodetectors have limitations in performance.
- Ultraviolet (UV) detection requires efficient carrier transport mechanisms.
Purpose of the Study:
- To investigate the UV photoresponse of a p+-Si/n-ZnO bilayer structure.
- To compare its performance against single-layer ZnO devices.
Main Methods:
- Fabrication of a p+-Si/n-ZnO bilayer photodetector.
- Characterization of its ultraviolet photoresponse properties.
- Analysis of carrier transport mechanisms.
Main Results:
- The bilayer device functions as two series-connected p-n junctions.
- Photo-induced carriers are modulated by the built-in electric field.
- Longitudinal carrier movement shortens charge migration paths, enhancing performance.
Conclusions:
- The p+-Si/n-ZnO bilayer structure offers superior responsivity and response speed for UV detection.
- This design overcomes limitations of conventional lateral transport in single-layer devices.
