Ag-S共掺ZnO的氧空位自补偿抑制及稳定p型转化的实现

发布时间：2018-03-03 07:20

本文选题：p型ZnO　切入点：氧空位　出处：《燕山大学》2015年硕士论文　论文类型：学位论文

【摘要】：作为典型的宽禁带半导体材料之一,氧化锌(Zn O)抗辐射能力强、激子束缚能高等优异的性能使其在光电、铁磁、光敏等领域具备广阔的应用前景。由于Zn O中存在着大量的本征施主缺陷所造成的自补偿效应,导致Zn O在杂质掺杂改性方面呈现单极性,其p型特性很难实现。并且其p型杂质受主能级普遍偏高,且固溶度较低,使得其p型特性不能稳定保持,严重制约着其在光电领域的应用,因此实现稳定有效的p型Zn O转变具有重大意义。本文基于密度泛函理论的第一性原理,针对Zn O中普遍存在的较为稳定的本征施主缺陷氧空位(VO),在考虑氧空位缺陷的情况下对Zn O进行p型掺杂。论文以Ag原子替位Zn原子形成的替位缺陷作为受主杂质,通过引入S原子来调节Ag的固溶度,降低其受主能级,并在一定程度上抑制氧空位的自补偿效应。论文首先通过研究Ag掺杂理想Zn O与含氧空位Zn O的能带结构和态密度,分析了氧空位对Ag掺杂的自补偿效应的内部机理;然后进一步研究了不同Ag、S、VO浓度配比的Zn O体系的电子结构,分析了引入S对抑制氧空位自补偿效应以及提升Ag的固溶度、降低受主能级的机制;最后计算了不同体系下的杂质元素结合能及缺陷形成能,确定了p型掺杂的有效性和体系的稳定性。论文研究发现S元素的引入可以在辅助Ag实现Zn O的p型转化的同时,抑制氧空位的自补偿效应等不利影响。采用Ag、S、氧空位(VO)的浓度比为1:2:1时更能最优化的保证Zn O的p型导电特性。
[Abstract]:As one of the typical wide band gap semiconductor materials, zinc oxide (ZnO) has strong radiation resistance, high exciton binding energy, high performance in optoelectronic, ferromagnetic, Guang Min and other fields have broad application prospects. Due to the existence of a large number of intrinsic donor defects in Zno, the self-compensation effect leads to the monopole of Zn O in impurity doping modification. The p-type characteristic is very difficult to realize, and its p-type impurity acceptor energy level is generally on the high side, and the solid solubility is low, which makes its p-type characteristic unstable, which seriously restricts its application in the field of optoelectronics. Therefore, it is of great significance to realize a stable and effective p-type Zn O transition. This paper is based on the first principle of density functional theory. In view of the existence of stable oxygen vacancies of intrinsic donor defects in Zn O, Zn O was doped with p type under the consideration of oxygen vacancy defects. In this paper, the substitution defects formed by the substitution of Zn atoms at Ag atoms were used as acceptor impurities. By introducing S atoms to adjust the solid solubility of Ag, reduce its acceptor energy level, and restrain the self-compensation effect of oxygen vacancy to some extent. Firstly, the energy band structure and density of states of Ag doped ideal Zn O and oxygen containing vacancy Zn O are studied. The internal mechanism of self-compensation effect of oxygen vacancy on Ag doping was analyzed, and then the electronic structure of Zn / O system with different Ag-Sn-VO concentration ratio was studied, and the effect of introducing S on suppressing oxygen vacancy self-compensation effect and enhancing Ag solid solubility were analyzed. Finally, the binding energy of impurity elements and the formation energy of defects in different systems are calculated. The efficiency of p-type doping and the stability of the system are determined. It is found that the introduction of S element can assist Ag to realize p-type conversion of Zno. The negative effects such as self-compensation effect of oxygen vacancy are suppressed. The concentration of oxygen vacancy VOO is better than that of 1: 2: 1 to ensure the p-type conductivity of Zn-O.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304

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