摘要
采用磷注入法合成磷化铟(InP)熔体,用液封直拉(LEC)法生长了不同化学配比的掺铁(Fe)InP单晶。用红外吸收光谱研究了化学配比对掺Fe InP单晶中Fe激活效率的影响。结果表明,富磷条件下Fe的激活效率高于配比及富铟条件,分析其影响机理,认为与不同配比条件下铟空位(V_(In))的形成能有关。通过第一性原理计算了不同配比条件下V_(In)和中性态缺陷Fe_(In)^(0)的形成能,发现富铟条件V_(In)和Fe_(In)^(0)的形成能最高,分别为5.28 eV和-3.50 eV,配比条件V_(In)和Fe_(In)^(0)的形成能次之,分别为3.99 eV和-5.22 eV,而富磷条件V_(In)和Fe_(In)^(0)的形成能最低,分别为2.84 eV和-6.83 eV。此外,还计算了费米能级E_F在InP的禁带宽度内,带电态缺陷Fe_(In)^(-1)与E_F的关系。发现在相同E_F下,富磷条件下Fe_(In)^(-1)的形成能均小于配比和富铟条件下Fe_(In)^(-1)的形成能。因此,富磷条件使得晶体中V_(In)浓度升高,致使Fe杂质更容易以替铟位的形式存在,导致Fe的激活效率更高。
A phosphorus injection method was used to synthesize indium phosphide(InP)melt,and the liquid encapsulated Czochralski(LEC)method was used to grow Fe-doped single crystal with different stoichiometry.The effect of the stoichiometry on Fe activation efficiency in Fe-doped InP single crystal was studied by infrared absorption spectroscopy.The results indicate that Fe activation efficiency under phosphorus-rich condition is higher than that of stoichiometric and indiumrich conditions.It is believed this phenomenon are related with the formation energy of indium vacancies(VIn).The formation energies of VIn and Fe_(In)^(0) under different stoichiometry were calculated by first principles.It is found that their formation energies are the highest under indium-rich condition,which are 5.28 eV and-3.50 eV,respectively.The second highest under stoichiometric condition,their formation energies are 3.99 eV and-5.22 eV,respectively.However,under phosphorus-rich condition,their formation energies are the lowest,which are 2.84 eV and-6.83 eV,respectively.In addition,the relationship between the charged state defect Fe_(In)^(-1)and Fermi level E_(F) within the bandgap of InP was calculated.It is found that under the same E_(F),the formation energy of Fe_(In)^(-1)is less than that under stoichiometric and indium-rich conditions.Therefore,the concentration of V_(In)is increased in phosphorus-rich condition,which makes it easier for Fe atoms to exist at indium site,resulting in higher Fe activation efficiency.
作者
黄子鹏
杨瑞霞
孙聂枫
王书杰
陈春梅
HUANG Zipeng;YANG Ruixia;SUN Niefeng;WANG Shujie;CHEN Chunmei(School of Electronic and Information Engineering,Hebei University of Technology,Tianjin300401,China;The 13th Research Institute,CETC,Shijiazhuang050051,China;China Nanhu Academy of Electronics and Information Sciences,Jiaxing314051,Zhejiang Province,China)
出处
《电子元件与材料》
CAS
CSCD
北大核心
2021年第7期654-659,共6页
Electronic Components And Materials
基金
国家自然科学基金(61774054,51871202,51401186)。
