非磁性/磁性掺杂剂对SnO_(2)体系的性能调控  

The optimal tuning of SnO_(2)systems by non-magnetic dopant/magnetic dopant

作　　者：高禹 郭华忠[1] GAO Yu;GUO Hua-Zhong(College of Physics,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学物理学院,成都610065

出　　处：《四川大学学报（自然科学版）》2023年第5期157-170,共14页Journal of Sichuan University(Natural Science Edition)

基　　金：科技部重点研发计划(2022YFF0608302);四川大学理科特色方向培育计划(2020SCUNL209)。

摘　　要：本文通过第一性原理计算在GGA+U框架下系统地研究了非磁性掺杂剂(Li)和磁性掺杂剂(V)以及相应的点缺陷(V_(O)/V_(Sn))掺杂SnO_(2)基稀磁半导体(DMS)的稳定性、电子结构、键合性质、磁性以及光学性质.计算得到的形成能结果表明,V元素单掺杂体系比Li元素单掺杂体系更稳定.其中,V_(O)存在的掺杂体系稳定性更高,而VSn对掺杂体系的稳定性不利.磁性分析表明,Li掺杂体系的磁矩大于V掺杂体系的磁矩.当有点缺陷存在时,VSn的加入显著提高了掺杂体系的磁性,而V_(O)对非磁性金属元素/磁性金属元素掺杂体系的磁性影响不同:当V_(O)存在于Li掺杂体系时,Li原子周围的O原子自旋极化减少,因此导致磁矩降低;当V掺杂体系中有V_(O)存在,磁性不仅来源于V原子的自旋极化,同时来源于V_(O)周围的O原子的自旋极化,因此磁矩增大.结合电子结构分析可知,Li掺杂体系的磁性是由O-p和Li-p轨道之间的双交换作用产生的,V掺杂体系的磁性是由O-p和V-d轨道之间的双交换作用产生的.键合分析发现V_(O)的存在可以提高两种金属掺杂体系键(Li-O和V-O)的共价性.在可见光区域内,Sn_(15)LiO_(32)和Sn_(15)VO_(32)具有较高的光学透明度.以上这些结果为非磁性金属元素(Li)和磁性金属元素(V)及相应的点缺陷(V_(O)/VSn)掺杂SnO_(2)在自旋电子器件中的应用提供了新的思路.In this paper,the stability,the electronic structure,the bonding stations,as well as the magnetic and optical properties of non-magnetic dopants(Li),magnetic dopants(V),and the corresponding point defects(V_(O)/V_(Sn))on SnO_(2)-based dilute magnetic semiconductors(DMS)are systematically investigated through ab-initio calculations.All the calculations are carried out within the GGA+U framework.The calculated formation energy results showed that the V single-doped system is more stable than the Li single-doped system.Among them,the doping system with V_(O)had higher stability,while VSn was unfavorable for the stability of the doping system.The magnetic analysis showed that the magnetic moment of the Li-doped system is larger than that of the V-doped system.The addition of VSn significantly improved the magnetic properties of the doped system,while the presence of V_(O)had different effects on the magnetic properties of the non-magnetic metal element/magnetic metal element doped system.When V_(O)is present in the Li-doped system,the spin polarization of the O atoms around the Li atom is reduced,thus leading to a lower magnetic moment.When V_(O)is set in the V-doped system,the magnetic moment increases not only from the spin polarization of the V atom but also from the spin polarization of the O atoms around V_(O).Combined with the electronic structure analysis,it is clear that a spin-polarized double exchange effect in the Li-p and O-p orbitals,which leads to magnetism of the Li-doped system,and the magnetism of the V-doped system is generated by the spin-polarized double exchange effect between the O-p and V-d orbitals.The bonding analysis revealed that the presence of V_(O)enhances the covalency of the bonds(Li-O and V-O)of the two metal-doped systems.In the visible region,Sn_(15)LiO_(32)and Sn_(15)VO_(32)had relatively high optical transparency.These results provided new ideas for the application of non-magnetic metal elements(Li),magnetic metal elements(V),and the corresponding point defects(V_(O)/VSn)doped SnO

关 键 词：第一性原理 掺杂剂 点缺陷 电子结构 磁性 光学性质 

分 类 号：O47[理学—半导体物理]