黑磷单晶的制备及其多层微米带的电输运性质的研究

发布时间：2018-03-21 09:27

本文选题：黑磷微米带　切入点：生长机理　出处：《浙江大学》2017年博士论文　论文类型：学位论文

【摘要】：相对于零带隙的石墨烯与宽带隙的过渡金属硫化物,黑磷是一种直接带隙半导体且能带宽度随层数可调(块体带隙0.3eV,单层2.0eV),因其电学、光学及热学性能呈现出面内各向异性,近年来受到人们的广泛关注,在半导体光电器件领域拥有广阔的应用前景。高性能黑磷器件的开发与应用,离不开高质量的黑磷单晶的可控制备。早期制备块体单晶黑磷的方法,存在着高成本,低产率,原料不环保,制备过程耗时等缺点,而且黑磷单晶的生长机理还未明晰。鉴于此,在本文中我们系统研究了黑磷单晶的气相输运法生长,并揭示了其生长机理,初步研究了其电学性能。取得了以下创新性的研究成果:(1)可控生长高质量单晶黑磷。我们分别发展了温差法和恒温法制备黑磷晶体,高质量黑磷晶体的转化率高达97%,成本大幅降低,生长效率大幅提升。(2)揭示了单晶黑磷的生长机理。通过系统研究单晶黑磷的生长过程,发现了黑磷微米带的生长具有“自下而上”的行为。在生长过程中,红磷升华形成磷蒸气与金属卤化物形成P-Sn-I的成核点,磷在随后的降温过程中不断析出并形成黑磷单晶。揭示了金属Sn、Pb(或者它们的合金)以及I2在黑磷生长过程中的重要作用。另外我们发现黑磷的转化率与磷蒸气在低熔点金属中的溶解度密切相关。(3)制作了基于多层黑磷的场效应晶体管并研究了其输运性能。黑磷微米带由于晶体沿着(0k0)的解理面堆叠,因此更容易采用机械剥离法获得单层或多层黑磷薄膜,在此基础上制作了场效应晶体管并研究了其电学性能。综上所述,我们在黑磷晶体生长、单层或多层黑磷制备及器件制作等方面做出了较为系统的研究工作,而且黑磷薄膜的直接生长方面做了初步探索,相信为将来进一步研究黑磷薄膜的丰富物理性质及其应用奠定了一定的基础。
[Abstract]:Compared with graphene with zero band gap and transition metal sulfide with wide band gap, black phosphorus is a direct band gap semiconductor with tunable energy band width (bulk band gap 0.3 EV, single layer 2.0 EV, due to its electrical, optical and thermal properties showing internal anisotropy. In recent years, people pay more and more attention to the development and application of high performance black phosphorus devices, which are widely used in the field of semiconductor optoelectronic devices. The method of preparing bulk single crystal black phosphorus in the early stage has the disadvantages of high cost, low yield, unfriendly raw material, time consuming and so on. And the growth mechanism of black phosphorus single crystal is not clear. In view of this, we have systematically studied the vapor phase transport growth of black phosphorus single crystal and revealed its growth mechanism. The electrical properties of the crystal were preliminarily studied. The following innovative research results were obtained: 1) the controllable growth of high quality single crystal black phosphorus. We developed the temperature difference method and the constant temperature method to prepare the black phosphorus crystal. The conversion rate of high quality black phosphorus crystal is as high as 97%, the cost is greatly reduced, and the growth efficiency is greatly improved. The growth mechanism of single crystal black phosphorus is revealed. The growth process of single crystal black phosphorus is studied systematically. It is found that the growth of the black phosphorus micron band has a "bottom-up" behavior. During the growth process, the red phosphorus sublimates to form the nucleation point of P vapor and metal halide to form P-Sn-I. Phosphorus precipitates and forms black phosphorus single crystals during subsequent cooling process. The important role of metal SnPb (or their alloys) and I2 in the growth of black phosphorus is revealed. In addition, we find that the conversion of black phosphorus and phosphorus vapor in black phosphorus. The field effect transistors based on multilayer black phosphorus have been fabricated and their transport properties have been studied. The black phosphorus micron band is stacked along the cleavage surface of the crystal. Therefore, it is easier to obtain monolayer or multilayer black phosphorus thin films by mechanical stripping. Based on this, the field effect transistors are fabricated and their electrical properties are studied. The preparation of monolayer or multilayer black phosphorus and the fabrication of devices have been studied systematically, and the direct growth of black phosphorus thin films has been preliminarily explored. It is believed that it will lay a foundation for the further study of the rich physical properties and applications of black phosphorus films in the future.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O613.62

【参考文献】