Structural Optimization and Trap Effects on the Output Performance of 4H-SiC Betavoltaic Cell

Area of Science:

• Semiconductor device physics
• Materials science
• Nuclear energy conversion

Background:

• Betavoltaic (BV) cells offer long-lasting power sources.
• Silicon carbide (SiC) is a promising material for BV cells due to its wide bandgap and radiation hardness.
• Optimizing device structure and understanding defect impacts are key for performance enhancement.

Purpose of the Study:

• To perform structural optimization of a 4H-SiC p-i-n betavoltaic cell.
• To analyze the impact of trap states on device performance under electron-beam irradiation.
• To identify critical factors for improving the efficiency and reliability of SiC-based BV cells.

Main Methods:

• Utilized Silvaco ATLAS TCAD software for device simulations.
• Incorporated an electron-beam (e-beam) irradiation model.
• Systematically varied intrinsic layer thickness, p-layer thickness, and intrinsic layer doping concentration for structural optimization.
• Introduced and varied densities of donor- and acceptor-like traps to assess their effects.

Main Results:

• Optimized device structure parameters were identified.
• Electron-hole pairs generated in the intrinsic layer were effectively utilized.
• Traps were found to degrade performance via charge capture and recombination.
• Acceptor-like traps in the intrinsic layer significantly reduced open-circuit voltage and maximum output power density.

Conclusions:

• Effective control of trap states, particularly acceptor-like traps in the intrinsic layer, is essential for high-performance SiC betavoltaic cells.
• The intrinsic layer is the most sensitive region to performance degradation caused by traps.
• This research provides critical insights for designing efficient and reliable SiC-based betavoltaic devices.