AI 中文总结
该研究通过第一性原理方法，对B掺杂、Y掺杂及（B，Y）共掺杂的α-Fe₂O₃进行研究，分析其声子色散特性和光学响应，揭示了掺杂对晶格动力学和光-物质相互作用的影响，为定制赤铁矿用于多种技术提供有效策略。
AI 中文摘要
理解掺杂对半导体材料晶体结构和光学性质的影响对推进下一代半导体和光子技术至关重要。尽管已有各种关于掺杂赤铁矿（α-Fe₂O₃）的研究，但动力学稳定性与光学性质之间的关系仍未得到充分探索。本研究进行了全面的第一性原理研究，同时评估了B掺杂、Y掺杂和（B，Y）共掺杂α-Fe₂O₃的声子色散特性和频率相关光学响应。研究了有限温度下的振动性质、介电函数和光学特性，以理解电磁辐射下的晶格动力学和光-物质相互作用。振动热力学表明，原始和Y掺杂的赤铁矿保持动态稳定性，而B掺杂的赤铁矿表现出虚声子模式表明由于Fe-O框架的畸变导致晶格不稳定。值得注意的是，Y与B共掺杂有助于抑制这些软模式，通过晶格弛豫和改善原子间力恢复结构稳定性。B掺杂通过在价带中引入额外状态增强低能吸收，而Y掺杂改变轨道杂化，导致更宽的色散。在光学区域，掺杂赤铁矿在2 eV以下显示出主导的带间跃迁，并在1.8 eV和4 eV之间有强吸收。（B，Y）共掺杂结合了低能优势和改善的光学响应曲线。总之，掺杂显著增强了晶格振动、光-物质相互作用和光学响应，为在光活性、光电子和光子技术的各种应用中定制赤铁矿提供了有效策略。
英文摘要
Understanding the effects of doping on the crystal structure and optical properties of semiconductor materials is crucial for advancing next-generation semiconductor and photonic technologies. Although various studies have focused on doped hematite ($α$-Fe$_2$O$_3$), the relationship between dynamical stability and optical properties remains insufficiently explored. This study presents a comprehensive first-principles investigation that simultaneously evaluates the phonon dispersion characteristics and frequency-dependent optical response of B-doped, Y-doped, and (B, Y)-co-doped $α$-Fe$_2$O$_3$, providing deeper insights into the underlying mechanisms. We examined the finite-temperature vibrational properties, dielectric function, and optical characteristics to comprehend the lattice dynamics and light-matter interactions under electromagnetic radiation. Vibrational thermodynamics reveal that pristine and Y-doped hematite maintain dynamic stability, while B-doped hematite exhibits imaginary phonon modes indicating lattice instability due to distortions in the Fe--O framework. Notably, Y co-doping with B helps suppress these soft modes, restoring structural stability through lattice relaxation and improved interatomic forces. B doping enhances low-energy absorption by introducing additional states in the valence band, while Y doping alters orbital hybridization, leading to a broader dispersion. In the optical regime, doped hematite displays dominant interband transitions below $2$ eV and strong absorption between 1.80 eV and 4 eV. The (B, Y) co-doping combines the low-energy benefits with an improved optical response profile. In summary, doping significantly enhances lattice vibrations, light-matter interactions, and optical responses, providing an effective strategy for tailoring hematite for diverse applications in photoactive, optoelectronic, and photonic technologies.
