基于第VA族元素形成的二维材料的结构和性能研究

发布时间：2018-02-24 06:08

本文关键词： 第一性原理计算磷烯掺杂二元VA-VA族半导体化合物异质结构　出处：《郑州大学》2017年博士论文　论文类型：学位论文

【摘要】：自石墨烯(Graphene)被发现以来,原子厚度的二维材料以其独特的性质得到广泛的关注。如今已发现的二维层状纳米材料除了石墨烯还有硅烯、锗烯、h-BN、MoS2和WS2、PbI和MoCl、MnO2和WoO3、Mg6Al2(OH)16等。同时一些其他二维层状材料也被相继报道,例如过渡金属碳/氮化合物(MXenes)、硼烯(Borophene)以及磷烯(Phosphorene)等。其中,二维磷烯的出现极大地启发了第VA族二维材料体系的研究探索。本论文着眼于VA族元素形成的二维材料体系,采用基于密度泛函理论的第一性原理研究方法,对VA族元素形成的磷烯以及原子厚度的二元VA-VA族半导体化合物的结构和性能进行系统研究。本论文的研究内容和结论如下:1.利用第一性原理密度泛函理论计算,研究了IIIA、IVA、VA、VIA族非金属原子(如B,C,N,O等)替代掺杂的二维磷烯的几何结构、电子结构和热力学稳定性。研究发现掺杂体系存在反常的掺杂效应,即掺杂体系的电子属性可以被掺杂原子的价电子数强烈地调制:奇数价电子的掺杂原子(如B,N等IIIA、VA族元素的原子),使得掺杂体系保持半导体属性;偶数价电子的掺杂原子(如C,O等IVA、VIA族元素的原子),使得掺杂体系具有金属属性。随着掺杂原子最外层电子数的奇偶变化,掺杂体系的带隙呈现半导体-金属-半导体-金属的振荡,这种反常的奇-偶振荡效应归因于掺杂原子的最外层电子对磷烯中特殊的孤对电子的调制。研究结果为调制磷烯基电子器件及光电子器件的输运性能提供了有效的途径。2.研究了过渡金属(如Sc,Ti,V,Cr,Mn,Fe,Co,Ni等)掺杂的二维黑磷磷烯以及蓝磷磷烯的稀磁半导体以及半金属属性。研究发现,对于黑磷磷烯掺杂来说,Ti,V,Cr,Mn,Fe以及Ni掺杂体系呈现稀磁半导体属性,而Sc和Co掺杂体系呈现非金属性;而对于蓝磷磷烯掺杂体系来说,V,Cr,Mn及Fe掺杂体系呈现稀磁半导体属性,Ni掺杂体系呈现半金属属性,而Sc和Co掺杂体系呈现非金属属性。这些新奇的稀磁半导体和半金属属性源于过渡金属3d电子与磷烯的孤对电子的相互作用。3.寻找新奇的二维半导体材料对于发展下一代低维电子器件具有重要意义。利用第一性原理计算,预测了一系列二维VA-VA族原子厚度的半导体化合物,如α-(β-)PN,AsN,SbN,AsP,SbP,SbAs等。通过声子谱和室温分子动力学的计算,验证了这些半导体化合物具有室温稳定性;而具有层状块体结构的AsP和SbAs,其单层的稳定性最好。能带结构的计算表明,α结构的半导体化合物具有直接带隙,而β结构的具有间接带隙;且大多数VA-VA族单层半导体化合物的带隙在可见光范围(1.59~3.26eV),表明其是太阳能电池的候选材料。由于AsP特殊的皱褶结构,其电子结构对拉伸/压缩应变非常敏感,带隙随着拉伸/压缩减小。SbN/Phosphorene异质结的能带结构几乎是单层SbN和黑磷磷烯的叠加,导致其带隙0.91eV和黑磷磷烯非常接近,可用于光电探测器等电子器件。研究成果不仅拓展了VA-VA族层状半导体化合物的视野,而且为VA-VA族二维材料在光电子和纳米电子半导体器件上的应用提供了史无前例的途径。4.目前,二维材料的垂直组装被视为设计电子器件和光电器件的令人激动的方法。利用第一性原理研究了GeSe/Phosphorene范德瓦尔斯异质结的结构和电子属性。研究结果表明,这种异质结为II-型异质结,且应变可以导致异质结由间接带隙到直接带隙、由金属到半导体转变。另外,产生了自发的电子—空穴分离,预示着此异质结在光电子器件应用方面可以作为候选材料。研究成果为GeSe/Phosphorene范德瓦尔斯异质结在未来的弹性电子、光电子和半导体器件上的应用提供有效途径。
[Abstract]:Since graphene (Graphene) has been found, the thickness of the atomic two-dimensional material has received wide attention for its unique properties. Two dimensional layered materials have now discovered that in addition to graphene and silylenes, germylene, h-BN, MoS2 and WS2, PbI and MoCl, MnO2 and WoO3, Mg6Al2 (OH) 16. At the same time, some other two-dimensional layered materials have been reported, such as transition metal carbon / nitrogen (MXenes), boron (Borophene) and allyl phosphinidene (Phosphorene). Among them, two phosphinidene has greatly inspired the research group VA of the two-dimensional material system exploration. This paper focus on the two-dimensional material system in VA the elements of group formation, using the first principle method based on density functional theory, a systematic study on the structure and properties of phosphinidene VA elements and the formation of atomic thickness two yuan VA-VA semiconductor compounds. The research contents and conclusions are as follows: 1. using the first principle density functional theory study of IIIA, IVA, VA, VIA and non metal atoms (such as B, C, N, O) the geometrical structure of two-dimensional phosphinidene substitution doped, electronic structure and thermodynamic stability. The study found that doping system exists abnormal doping effect, namely the electronic properties of doped the system can be the number of valence electron doped atoms strongly modulated doping atoms: odd valence electrons (such as B, N, IIIA, VA elements, the atoms) doped semiconductor doping properties remain; even the valence electrons (such as C, O, IVA, VIA elements, the atom) the doped system with metal properties. With the changes of the doping parity number of electrons in the outermost shell, the band gap of a semiconductor doped metal semiconductor metal oscillation, this anomalous odd even oscillations due to doping atoms on the outermost electron phosphinidene special lone pair Electronic modulation. The results for the modulation of phosphorus alkenyl electronic devices and optoelectronic devices and transport properties of.2. provides the effective way of transition metal (such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni) two-dimensional black phosphorus doped graphene and graphene blue diluted magnetic semiconductor with phosphorus and half metallic properties. The study found that the black phosphorus doped graphene, Ti, V, Cr, Mn, Fe and Ni doped system showed diluted magnetic semiconductor properties, while Sc and Co showed non metal doped system; while for the blue phosphorus doped graphene system, V, Cr, Mn and Fe were doped system the diluted magnetic semiconductor properties of Ni doped system presents half metallic properties, while Sc and Co doped system showed non metallic properties. These novel diluted magnetic semiconductors and half metallic properties derived from transition metal 3D electrons and phosphinidene lone electron pair interaction.3. for two-dimensional semiconductor materials for the development of new generation low Has the important dimension of electronic devices. Using the first principle calculation, a series of 2D VA-VA atoms thickness of semiconductor compounds was predicted, such as alpha (beta) PN, AsN, SbN, AsP, SbP, SbAs and so on. The phonon spectra and room temperature molecular dynamics calculation, verified these semiconductor compounds with room temperature stability; with block like structure of AsP and SbAs, the stability of the single best. The band structure calculation shows that the structure of alpha compound semiconductor with a direct band gap, while beta structure has an indirect band gap; and most of the VA-VA family of single semi conductor band gap of the compound in the visible range (1.59~3.26eV). That is a candidate material for solar cell. Because of the special AsP folded structure, the electronic structure is very sensitive to the tensile / compressive strain, the band gap decreases with the tensile / compressive.SbN/Phosphorene heterojunction band structure is almost SbN and single Black phosphorus was superimposed, resulting in the band gap of 0.91eV and black phosphorus graphene is very close, can be used for photoelectric detector and other electronic devices. The results not only expand the VA-VA layered semiconductor compounds and vision for the application of VA-VA family of two-dimensional materials in optoelectronics and nano electronic semiconductor devices on the.4. provides a way There was no parallel in history. at present. Assembly method of vertical two-dimensional material is regarded as the design of electronic devices and optoelectronic devices exciting. Structure and electronic properties of GeSe/Phosphorene heterojunction Van Der Waals using the first principle. The results show that the heterojunction type II- heterojunction, and strain can lead to the heterojunction by indirect bandgap to direct band gap and from metal to semiconductor transition. In addition, the electron hole separation spontaneously, this indicates that the heterojunction optoelectronic devices can be applied in time Material selection. The research results provide an effective way for the application of GeSe/Phosphorene Van Der Waals heterojunction in the future of elastic electrons, optoelectronic and semiconductor devices.

【学位授予单位】：郑州大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O469

【相似文献】