Ru、Rh、Pd掺杂GaSb的电子结构和光学性质

Electronic Structures and Optical Properties of Ru,Rh,Pd Doped GaSb

运用第一性原理计算方法研究了过渡族金属TM(TM=Ru、Rh、Pd)掺杂GaSb的电子结构和光学性质,结果表明:TM掺杂GaSb主要以TM替代Ga(TM@Ga)缺陷存在,并可增强GaSb半导体材料对红外光区光子的响应,使体系光学吸收谱的吸收边红移;TM@Ga所引入的杂质能级分布于零点费米能级附近,这极大地增强了体系的介电性能,促进了电子-空穴对的产生和迁移,因而提升了掺杂体系的光电转换效率;Ru掺杂对GaSb光学性质的改善最为明显,当掺杂浓度为6.25%(原子数分数)且均匀掺杂时,Ru掺杂GaSb体系对红外光区光子的吸收幅度最大,有效提升了GaSb光电转换效率和光催化活性。

Electronic structures and optical properties of transition metal(TM,TM refers to Ru,Rh and Pd,respectively)doped GaSb were studied by first-principles calculations.The results show that the three TMs are more likely to substitute for Ga to form TM@Ga defect and enhance the response of GaSb semiconductor to infrared photons,making the optical absorption edge of the system red shift.The doped TM@Ga introduce impurity levels distributed around the Fermi level in the band gap,which greatly strengthens the dielectric properties of the system.The enhancement of the photoelectric field intensity can promote the generation and migration of electron-hole pairs,thus improving the photoelectric conversion efficiency of GaSb semiconductor.The optical properties of TM@Ga doped GaSb are all superior to that of undoped system,but Ru is the best choice among the three dopants.Moreover,the molar concentration and location of Ru also have an impact on optical properties of GaSb semiconductor.The absorption amplitude of Ru-GaSb is the biggest when the concentration is 6.25%(atomic fraction),which can improve the photoelectric conversion efficiency and photocatalytic performance effectively.