Theory of Tetrahedral Amorphous Carbon

9322412 Drabold这是一个新的奖项，用于研究四面体无定形碳的计算密集型理论研究。最近已经证明，非晶碳的四配位形式，即四面体非晶碳，是一种半导体，既可以正向掺杂，也可以负向掺杂，具有光导性，已被用于制造简单的器件。将进行一项理论研究计划，以确定这种材料的性能。这项研究将利用第一性原理方法对原子尺度结构和电学性质进行详细研究。非晶态网络中的缺陷将被识别，并将检查它们对载流子传输的影响。几种杂质的性质，特别是已证实的浅施主的性质，将被探索。将对氢对材料性能的影响进行有限的研究。材料的表面结构将被确定，以期产生对未来原子学或蒙特卡罗生长研究有用的表面结构模型。还将研究该材料的振动特性和稳定性。一项补充工作将针对提高现有计算技术的效率，以模拟四面体无定形碳和其他化学结合材料的第一性原理。这是一个研究无定形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一种半导体。因此，这种材料似乎具有许多令人满意的钻石的电子特性。这项研究将为这种新材料提供第一批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. ***