N等离子体处理ZnO基半导体材料的铁磁性增强

论文总字数：26743字

摘 要

本文主要研究了在氮的等离子体处理下，氧化锌基半导体铁磁性的增强，氧化锌(ZnO)是一种六角纤锌矿结构的半导体，并且为直接宽带隙，其在300K下的禁带宽度为3.37eV，有较高的激子束缚能，为60meV，使其在短波长发光方面有十分诱人的应用前景，同时，在室温下的铁磁性也颇有研究价值，。因而受到研究者的广泛关注。

作为宽间隙半导体的ZnO几乎全部是n型导电，并且到目前为止多年来p型掺杂一直是一个挑战并不令人惊讶。 而I族元素Li和Na在所有其他II-VI半导体中形成浅受主能级，它们在ZnO中引入深受体态，结合能在500和800meV之间。 考虑到ZnSe：N的成功，在V族元素中氮可能是最佳候选者¹。

ZnO是典型的氧化物半导体材料，在光电领域具有重要的应用价值。理论上预言了通过掺杂等方式可以在ZnO中实现高于室温的铁磁性，然而实验上却没有得到公认的结果。这主要就是ZnO掺杂后磁性比较微弱，很难排除杂质等的影响。本项目我们将在制备ZnO粉体材料的基础上，通过不同流量、功率的N等离子体气氛下处理前后磁性的变化，研究ZnO中杂质缺陷等种类和浓度的改变，对ZnO室温磁性的影响。而N等离子体处理还可以尽量避免制备过程中杂质的引入，使可能获得的铁磁性更有说服力。

关键词：氮等离子体，氧化锌，半导体，铁磁性

Abstract

This paper mainly studies the enhancement of ferromagnetism of zinc oxide-based semiconductor under nitrogen plasma treatment. Zinc oxide (ZnO) is a hexagonal wurtzite structure semiconductor, and it is a direct wide band gap, and its band gap at 300K. With a width of 3.37 eV and a high exciton binding energy of 60 meV, it has a very attractive application prospect in short-wavelength luminescence. At the same time, ferromagnetism at room temperature is also of great research value. Therefore, it has received extensive attention from researchers.

ZnO, which is a wide gap semiconductor, is almost entirely n-type conductive, and it has not been surprising that p-doping has been a challenge for many years. The Group I elements Li and Na form shallow acceptor levels in all other II-VI semiconductors, which introduce deep acceptor states in ZnO with binding energies between 500 and 800 meV. Considering the success of ZnSe:N, nitrogen may be the best candidate 1 in the V group element.

ZnO is a typical oxide semiconductor material and has important application value in the field of optoelectronics. Theoretically, it is predicted that ferromagnetism above room temperature can be achieved in ZnO by doping, but no results have been obtained. This is mainly because the magnetic properties of ZnO doping are relatively weak, and it is difficult to eliminate the influence of impurities. In this project, we will study the magnetic properties of ZnO powder materials before and after treatment by N-plasma atmosphere with different flow rates and powers to study the effects of impurity defects and other changes in ZnO on the magnetic properties of ZnO at room temperature. The N plasma treatment can also avoid the introduction of impurities during the preparation process, making the possible ferromagnetism more convincing.

KEYWORDS: nitrogen plasma, zinc oxide, semiconductor, ferromagnetism

目 录

摘要 ……………………………………………………………………………………………Ⅰ

Abstract …………………………………………………………………………………… Ⅱ

1. 绪论………………………………………………………………………………1

1.1引言………………………………………………………………………………1

1.2 p型ZnO研究现状………………………………………………………………………………3

1.3 N掺杂ZnO现有的研究成果………………………………………………6

1.4本实验的研究目的和主要研究内容………………………………………………8

1.5 氮掺杂氧化锌铁磁性增强原理 第一性原理计算…………………10

第二章 实验方法与实验内容……………………………………………………12

2.1 氧化锌的制备……………………………………………………12

2.2 氮等离子体处理氧化锌……………………………………………………12

2.3测量结果……………………………………………………12

结论……………………………………………………………………………………………15

参考文献……………………………………………………………………………………………17

致谢……………………………………………………………………………………………19

1. 绪论
   1. 引言

作为半导体而言，ZnO的能带隙和激子束缚能比较大，透明度也高，有优异的常温发光性能，在半导体领域，尤其是液晶显示器、薄膜晶体管、发光二极管这类产品中均有应用。除此之外，微颗粒的ZnO也作为一种纳米材料，开始在相关领域发挥作用。将铁磁性引入到传统半导体材料中，将在微电子器件中应用电子的电性质的基础上，增加电子自旋的自由度，扩展了调控的参数，使传统微电子器件获得了更多的功能，打破微电子器件尺度不断减小而逐渐逼近的量子效应的限制。

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