Radiative and Non-radiative Centers in Indium Phosphide Alloy Thin Films and Heterostructures

对外延磷化铟及其铝镓合金的辐射缺陷和非辐射缺陷进行基础研究。研究了故意掺杂合金所产生的缺陷及其性能；需要研究的具体缺陷现象包括：1)自补偿深层缺陷的形成和稳定性；2)与简单取代杂质相关的深层供体层的形成；3)等电子、稀土中心及其配合物。采用金属有机气相外延法制备磷化铟合金薄膜和异质结构。光致发光、光电导率和深能级瞬态光谱将用于确定缺陷参数和缺陷稳定性。为了确定辐射和非辐射深能级缺陷的对称性和识别，将使用偏振激发光谱，并将结果与其他对称敏感测量结果进行比较。本文将探讨这些合金中缺陷稳定性的最新理论的适用性。关于稀土杂质及其配合物的电子和光学性质的最新理论将根据实验结果进行审查。研究影响复合半导体材料的电子和光学性能的因素。这项研究有望对缺陷对材料性能和性能的影响有一个基本的认识。所研究的半导体在电子和光电子器件中具有广泛的适用性；了解缺陷结构也将提高由这些材料制成的器件的性能。这些研究可能会产生新的光子材料和器件，以及目前用于计算、信息处理和电信的器件和集成电路的重大改进。

Fundamental studies of the radiative and non-radiative defects in epitaxial indium phosphide and its alloys with aluminum and gallium will be undertaken. Defects and their properties resulting from deliberate doping of the alloys will be investigated; specific defect phenomena to be studied include: 1)formation and stability of deep level native defects by self-compensation, 2)formation of deep donor levels associated with simple substitutional impurities, and 3)isoelectronic, rare-earth centers and their complexes. Indium phosphide alloy thin films and heterostructures will be prepared by metalorganic vapor phase epitaxy. Photoluminescence, photoconductivity and deep level transient spectroscopy will be used to determine defect parameters and defect stability. To determine the symmetry and identification of the radiative and non-radiative deep level defects polarized excitation spectroscopy will be used and the results compared to other symmetry sensitive measurements. The applicability of recent theories on native defect stability in these alloys will be examined. Recent theories on the electronic and optical properties of rare-earth impurities and their complexes will be examined with respect to experimental results. %%% Research will be conducted on the factors that influence the electronic and optical properties of compound semiconductor materials. This research is expected to give a fundamental understanding of the effect of defects on material properties and performance. The semiconductors under study have wide applicability in electronic and optoelectronic devices; understanding the defect structure will also improve the performance of devices made from these materials. New photonic materials and devices may result from these studies as well as significant improvements in devices and integrated circuits currently used in computing, information processing, and telecommunications.