Polarity Inversion-Driven Band Structure Modulation, Strain Engineering, and Electrical Property Analysis on...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Physics

Background:

• 4H-SiC/GaN heterojunctions offer excellent electrical properties for advanced semiconductor devices.
• Understanding heterojunction structures is crucial for optimizing device performance.

Purpose of the Study:

• To investigate the electronic and electrical characteristics of four different 4H-SiC/GaN heterojunction structures.
• To analyze the impact of varying polarity configurations on band structure and electron mobility.

Main Methods:

• Computational analysis of four distinct heterojunction structures (01-C-Si-Ga-N, 02-C-Si-N-Ga, 03-Si-C-Ga-N, 04-Si-C-N-Ga).
• Examination of band structures, electron distribution, and effective mass anisotropy.

Main Results:

• Structures 01 and 03 exhibit direct band gaps; structures 02 and 04 have indirect band gaps.
• Degenerate valence bands and band overlap observed in structures 01 and 04.
• Structure 03 shows symmetric electron distribution, potentially enhancing electron mobility to 18,527.2 cm²·V⁻¹·s⁻¹.
• Structure 04 features an electron depletion region that may improve hole mobility.

Conclusions:

• The electronic properties of 4H-SiC/GaN heterojunctions are highly dependent on polarity configuration and band structure type.
• Structure 03 demonstrates promising characteristics for high-electron-mobility applications.
• Anisotropic effective mass is a key feature influenced by the band structure in these heterojunctions.