Theory of Tetrahedral Amorphous Carbon

9322412 Drabold这是一个新的奖项，用于研究四面体非晶态碳的计算密集型理论研究。最近已经证明，四配位形式的非晶碳，四面体非晶碳，是一种半导体；可掺杂正负两种；显示出光导性，并已被用来制作简单的器件。将进行一项理论研究计划，以确定这种材料的性质。该研究将使用第一性原理方法对原子尺度结构和电学性质进行详细的研究。非晶网络中的缺陷将被识别，并将研究它们对载流子输运的影响。将探讨几种杂质的性质，特别是已证实的浅层供体。将对氢对材料性能的影响进行有限的研究。将确定材料的表面结构，以产生对未来原子或蒙特卡罗生长研究有用的表面结构模型。该材料的振动特性和稳定性也将被研究。一个补充的努力将指向提高现有的四面体非晶碳和其他化学键合材料的第一性原理模拟计算技术的效率。这是一个研究非晶态碳的性质的计算研究项目。这种材料已被证明具有许多有趣的特性，这些特性可能对微电子学产生重大影响，其中最重要的是它是半导体。因此，这种材料似乎具有金刚石的许多理想的电子特性。这项研究将为这种新材料提供第一个全面的理论研究之一。＊＊＊

9322412 Drabold This is a new award for computationally-intensive theoretical research to study tetrahedral amorphous carbon. It has recently been demonstrated that a fourfold-coordinated form of amorphous carbon, tetrahedral amorphous carbon, is a semiconductor; can be doped both positive and negative; shows photoconductivity and has been employed to make simple devices. A theoretical research program will be undertaken to determine the properties of this material. The research will provide detailed studies of the atomic scale structure and electrical properties using first principles methods. Defects in the amorphous network will be identified and their effects on carrier transport will be examined. The properties of several impurities, but especially the demonstrated shallow donors, will be explored. A limited study of the effects of hydrogen on material properties will be performed. The surface structure of the material will be determined with a view to producing surface structural models that will be useful to future atomistic or Monte Carlo growth studies. The vibrational properties and stability of the material will also be investigated. A complementary effort will be directed toward improvement of the efficiency of existing computational techniques for first principles simulations of tetrahedral amorphous carbon and other chemically bonded materials. %%% This is a compuational research project to study the properties of an amorphous form of carbon. This material has been shown to have many interesting properties which may have significant impact on microelectronics - not the least of which is that it is a semiconductor. Thus, the material seems to have many of the desirable electronic properties of diamond. The research will provide one of the first comprehensive theoretical studies of this new material. ***