Staebler-Wronski effect in tritiated amorphous silicon

氢化非晶硅(a-Si：H)是光伏和微电子领域最重要的材料之一。在非晶态材料中引入氚(氢的一种同位素)，促进了对悬挂键缺陷和亚稳性的基础研究。1995年，申请人开始了对氚非晶硅性能的系统研究。初步研究表明，氚可以永久地结合在非晶硅中，从而使这种放射性物质相对安全。与氚衰变相关的现象为研究非晶态半导体提供了一个非常有力的新工具。特别是，a-Si：H网络中的氚衰变可以用来模拟和分析导致a-Si：H光电性质退化的Staebler-Wronski(S-W)效应，此外，在衰变过程中释放的能量可以被利用并转化为其他有用和无害的能量形式。这项建议的主要目标是：更好地了解非晶态半导体的物理性质以及氚在非晶态半导体中的影响。本研究将从理论和实验两个层面进行。此外，能源“紧缺”将“核解决方案”带回了风口浪尖，而以坎杜反应堆为基础的加拿大核电站是氚气体的主要和独特来源。这项研究将促进氚在微电子设备中的开发和安全利用，并有可能通过探索含氚非晶态半导体的实际应用，包括自供电发光设备和电池，使加拿大工业受益。至少三名理科硕士最近批准的材料科学硕士项目的学生将参与为期5年的研究；几名本科生也将参与暑期项目。将为学生提供培训：i)使用从头算分子动力学(AIMD)来模拟半导体和其他材料的光电性质，ii)执行项目所需的实验测量。

Hydrogenated amorphous silicon (a-Si:H)-represents one of the most important materials in the areas of photovoltaics and microelectronics. The introduction of tritium (an isotope of hydrogen) into amorphous materials has spurred fundamental studies on the nature of dangling bond defects and metastability. In 1995 the applicant initiated a systematic research of the properties of tritiated amorphous silicon. Preliminary studies have shown that tritium can be permanently bonded in amorphous silicon, thereby rendering this radioactive substance relatively safe. Phenomena associated with the decay of tritium offer a very powerful new tool in the study of amorphous semiconductors. In particular, Tritium decay within the a-Si:H network can be used to simulate and analyze the Staebler-Wronski (S-W) effect, which is responsible for the degradation of the opto-electronic properties of a-Si:H. Furthermore, the energy released during the decay can be harnessed and transformed into other, useful and harmless, forms of energy. The main objectives of this proposal are: to achieve a better understanding of the physical properties of amorphous semiconductors and of the effects of tritium in amorphous semiconductors. The research will be conducted at both theoretical and experimental levels. In addition, the energy "crunch" has brought the "nuclear solution" back to the forefront, and the Canadian nuclear plants, based on the CANDU reactor, represent a major and unique source of Tritium gas. This research will lead to the development and to the safe utilization of tritium in microelectronic devices, having the potential to benefit Canadian industry via exploration of practical applications of tritiated amorphous semiconductors, including self-powered light emitting devices and batteries. At least three M.Sc. students in the recently approved Master in Materials Science program will be involved in the research over the course of 5 years; several undergraduate students will also be involved in summer projects. The students will be provided training to: i) use Ab Initio Molecular Dynamics (AIMD) to simulate optoelectronic properties of semiconductors and other materials, ii) perform the experimental measurements required for the project.