The Influence of Alkaline Earth Elements on Electronic Properties of α-Si3N4 via DFT Calculation

• 作 者: ZHANG Jianwen HUANG Zhifeng YIN Ziqian LI Meijuan CHEN Fei SHEN Qiang
• 机 构: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University
• 出 处: 武汉理工大学学报（材料科学版）（英文版）
• 发表日期: 2020年5期
• 关键词: first-principles density functional theory calculations alkaline earth elements

We used density functional theory (DFT) calculations to study the influence of alkali earth metal element (AE) doping on the crystal structure and electronic band structure of α-Si3N4. The diversity of atomic radii of alkaline earth metal elements results in structural expansion when they were doped into the α-Si3N4 lattice. Formation energies of the doped structures indicate that dopants prefer to occupy the interstitial site under the nitrogen-deficient environment, while substitute Si under the nitrogen-rich environment, which provides a guide to synthesizing α-Si3N4 with different doping types by controlling nitrogen conditions. For electronic structures, energy levels of the dopants appear in the bottom of the conduction band or the top of the valence band or the forbidden band, which reduces the bandgap of α-Si3N4.