Optical Studies of Electronic States, Vibrations and Relaxation Processes in Amorphous Systems

非晶系统中电子态、振动和弛豫过程的光学研究

• 批准号: 8706289
• 负责人: Jan Tauc
• 金额: $ 54.84万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-11-15 至 1991-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8706289&HistoricalAwards=false
• 关键词: Optical; Studies; Electronic; States; Vibrations

Studies will be made of electron states in the gap (in the bulk and at interfaces), carrier transport and recombinatiion processes in a-Si:H and related materials (undoped and variously doped films,and multilayer structures). CW and time-resolved photomodulation spectroscopy in a broad spectral range and time domain from femtoseconds to seconds will be used. Photogenerated carriers will be followed as they dribble down in energy through band states, different traps in the gap, and eventually recombine. In the femtosecond range, the pump and probe technique for studying energy, momentum and coherence relaxations of excited electronic states will be employed. In the picosecond range, a new technique, optical time-of-flight method will be used, for studying the carrier transport in a-Si:H at very short times, using the a-Si:H/a-SiNx:H multilayer structures. In the ranges fromnanoseconds up, studies will be made of the evolution of the carrier densities both in energy and time from which carrier transport between specific states in the gap and carrier recombination can be obtained. Another new method, cw photomodulation spectroscopy of vibrations, for identifying the bonding structures with which a certain electronic state in the gap is correlated will be used.

将研究差距中的电子状态（在体中 以及在界面处）、载体运输和重组 在a-Si：H和相关材料（未掺杂的和各种各样的）中的工艺 掺杂膜和多层结构）。 CW和时间分辨 宽光谱范围和时间的光调制光谱学 将使用从飞秒到秒的域。 光生 载流子将被跟踪，因为他们滴下的能量通过 带态，差距中的不同陷阱，最终 重组 在飞秒范围内，泵和探针 研究能量、动量和相干弛豫的技术 将使用激发的电子状态。 在皮秒 距离，一种新的技术，光学飞行时间方法将是 用于研究a-Si：H中的载流子输运 倍，使用a-Si：H/a-SiNx：H多层结构。 在 从纳秒开始，研究将由进化 载流子密度的能量和时间 在差距中的特定状态之间的载流子传输和载流子 可以实现重组。 另一种新方法，cw 振动的光调制光谱学，用于识别 键合结构，其中， 将使用gap。