Properties of hydrogen molecules in semi-conductors

半导体中氢分子的性质

• 批准号: 5427447
• 负责人: Professor Dr. Jörg Weber
• 金额: --
• 依托单位: Institut für Angewandte Physik (IAP)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5427447?language=en
• 关键词: Properties; hydrogen; molecules; semi; conductors

Hydrogen is now considered as one of the most important and well-understood impuirties in semiconductors though the 'simplest' possible H-related defect - H2 - was detected only in Si and GaAs and remains one of the less studied ones. The most unusual thing about H2 is that para (I = O) nuclear spin state of interstitial H2 in Si is not stable with respect to room temperature annealing and illimination with the bad gap light. This recently found phenomenon was tentatively explained by different diffusion rates of H2 in different nuclear spin states. Thus, detailed investigation of the H2 diffusion is the first task of the proposed project. In Si, Ge and GaAs high concentrations of hydrogen create extended planar defects called platelets. Under certain conditions these plavelets may hold H2 gas under high pressure. Two possibilities exist if this novel two-dimensional Bose system is cooled down to appropriate temperatures. Depending on the interacting potential between the molecules and the host, the H2 gas either forms a 2D crystalline structure or experiences Bose-Einstein condensation. Both possibilities are very attractive from a scientific point of view, making the study of 2D H2 gas a major task of the project. Raman scattering and Fourier tansform infrared spectroscopy are techniques to be employed to fulfill the goals outlined above.

氢现在被认为是半导体中最重要和最广为人知的缺陷之一，尽管最简单的可能与氢有关的缺陷-H2-只在硅和砷化镓中检测到，并且仍然是研究较少的缺陷之一。H_2的最不寻常之处在于，Si中间隙H_2的α(I=O)核自旋态对于室温下的退火和弱能隙光照射是不稳定的。这一新发现的现象可以用氢在不同核自旋态的不同扩散速率来解释。因此，对氢的扩散进行详细的研究是该计划的首要任务。在硅、锗和砷化镓中，高浓度的氢会产生扩展的平面缺陷，称为小片。在某些条件下，这些小板可以在高压下容纳氢气。如果这个新颖的二维玻色系统冷却到合适的温度，就有两种可能性。根据分子和主体之间的相互作用势，氢气要么形成2D晶体结构，要么经历玻色-爱因斯坦凝聚。从科学角度来看，这两种可能性都非常有吸引力，这使得对2D H2气体的研究成为该项目的一项主要任务。拉曼散射和傅里叶变换红外光谱是实现上述目标的技术。