Nuclear Magnetic Resonance Studies of Impurities in Semiconductors

小行星9623299 将使用杂质物质核磁共振（NMR） 到 研究晶体半导体中杂质的局部原子和电子结构。 我们之前在100 - 500 K范围内对Si（P）和Si（B）中施主和受主带的变温度研究将扩展到液氦温度。 本文采用常规杂质核核磁共振方法，在存在持久性杂质的情况下，对II-VI族材料中的III族杂质Ga和In进行了研究。 低温下的光电导性。 试图观察ZnO和相关的II-VI族材料的光学核极化。 光激发对碲化镉中杂质（如镓）的局部原子结构的影响将作为这些材料的“DX模型”的测试进行检查。 %杂质原子在技术上重要的半导体晶体中起着关键作用，因为它们引入了材料导电所需的带电载流子。 尽管它们的重要性，许多重要杂质的原子尺度环境仍然知之甚少。 核磁共振（NMR）提供了一种高度局部的、化学特异性的探针，其将用于 这 研究调查的结构 以及材料如CdTe和Si中所选杂质的电子环境。 CdTe和相关材料中Ga和In等原子的状态将受到特别关注，以试图理解为什么这些杂质， 到 传统的行为，不要 引入载体。 在Si中，NMR将用于阐明P或B杂质之间的相互作用影响载流子迁移率的方式，从而影响硅基器件的性能。 ***

9623299 Warren Impurity-species nuclear magnetic resonance (NMR) will be used to investigate the local atomic and electronic structure of impurities in crystalline semiconductors. Our previous variable-temperature studies of the donor and acceptor bands in Si(P) and Si(B) in the range 100 - 500 K will be extended to liquid helium temperatures. The group III impurities Ga and In in II-VI materials will be studied by conventional impurity-nucleus NMR in the presence of persistent photoconductivity at low temperatures. An attempt will be made to observe optical nuclear polarization in ZnO and related II-VI materials. The effect of optical excitation on the local atomic structure of impurities such as Ga in CdTe will be examined as a test of the "DX model" of these materials. %%% Impurity atoms play a critical role in technologically important semiconducting crystals since they introduce the charged carriers necessary for the materials to conduct electricity. Despite their importance, the atomic-scale environments of many important impurities are still poorly understood. Nuclear magnetic resonance (NMR) provides a highly local, chemically-specific probe which will be used in this research to investigate the structural and electronic environments of selected impurities in materials such as CdTe and Si. The state of atoms such as Ga and In in CdTe and related materials will receive particular attention in an attempt to understand why these impurities, contrary to conventional behavior, do not introduce carriers. In Si, NMR will be used to clarify the way in which interactions between P or B impurities influence the carrier mobility and hence, the performance of silicon-based devices. ***