La掺杂和空位对ZnS磁性和光学性能影响的第一性原理研究

利用密度泛函理论框架下的平面波超软赝势法,通过第一性原理对La掺杂与Zn空位(V_(Zn))及La掺杂与S空位(V_S)共存的ZnS体系的电子结构、磁性机理、形成能及吸收光谱进行了研究.结果表明, La掺杂与空位(V_(Zn)或V_S)的空间位置最近时,掺杂体系的形成能最低,体系最稳定.另外,La掺杂与Zn空位共存时,体系具有磁性,且体系的净磁矩与La原子与Zn空位的相对位置有关;La掺杂与S空位共存时,掺杂体系无磁性,但此时体系的禁带宽度最窄且吸收光谱红移最显著.

First-principles study of La doping and vacancy on the magnetism and optical properties of ZnS

Based on density functional theory, the formation energy, magnetism, electronic densities of states and absorption spectrum of ZnS system with the coexistence of La doping and vacancy (VZn or VS ) are calculated by using the first principle. Calculations reveal that in the system with the coexistence of La doping and vacancy(VZn or VS ), the relatively closer position between the dopant and vacancy will decrease the formation energy of the doping system and increase the stability of the system. Additionally, the ZnS system with the coexistence of La doping and Zn vacancy is magnetic and the magnetism is affected by the relative position between the dopant and vacancy. Meanwhile, the system of La doping and S vacancy is nonmagnetic but shows better photocatalytic properties.