SGER: An Investigation of Silicon Germanium Terahertz Sources

硼掺杂和镓掺杂的Si和SiGe层将通过分子束外延在Si衬底上生长。器件结构将使用光刻结合反应离子蚀刻和金属蒸发来制造。它们的电致发光特性将被确定为掺杂剂类型和浓度的函数。电气和光学设备建模将用于帮助解释观察结果。电致发光测量将在安装在低温恒温器中的傅立叶变换红外光谱仪中的电接触装置上进行，该傅立叶变换红外光谱仪在太赫兹范围内工作。特别地，将相对于所施加的电流和温度来确定发射强度和光谱。基于这些结果，我们将评估基于掺杂跃迁设计太赫兹激光器的可能性，即掺杂腔谐振器的辐射增益和损耗。由于掺杂态的激发机制及其辐射效率还没有得到很好的理解，因此建议的研究应被视为探索性和高风险，并将在本项目中进行探索。这项研究的潜在影响涉及太赫兹发射设备具有简单的结构，是潜在的低成本和广泛使用的硅集成电路兼容。与计算机芯片集成的紧凑型太赫兹发射器将应用于：化学和生物传感;医疗诊断和高带宽通信。SGER补助金将是支持工作的合适方式，因为结果将表明是否有理由进行额外的研究，并可用于寻求额外的资金。教育和推广活动将与这些研究活动相结合。这包括一名研究生参与研究，将研究成果纳入教学，以及继续开展一系列当地学校外展活动。将设计一个适合高中生或大学一年级学生的互动网站（http：//www.ece.udel.edu/terahertztools/terahertztools.htm），说明太赫兹频率的特性，让学生探索太赫兹吸收和反射现象。

Layers of boron doped and gallium doped Si and SiGe will be grown by molecular beam epitaxy on Si substrates. Device structures will be fabricated using photolithography combined with reactive ion etching and metal evaporation. Their electroluminescent properties will be determined as a function of dopant type and concentration. Electrical and optical device modeling will be used to help interpret the observations. Electroluminescence measurements will be made on electrically contacted devices mounted in a cryostat in a Fourier Transform Infrared Spectrometer that operates in the THz range. In particular, the emission intensity and spectrum will be determined versus the applied current and temperature. Based on the results, the possibility of designing a TeraHertz laser based on dopant transitions will be assessed in terms of the radiative gain and losses from doped cavity resonators.The proposed research should be considered exploratory and high risk because the excitation mechanism of the dopant states and their radiative efficiency is not well understood, and will be explored during this project. The potential impact of this research concerns a TeraHertz emitting device with a simple structure that is compatible with Si integrated circuitry for potential low cost and widespread use. Compact TeraHertz emitters that are integrated with computer chips would have applications in: chemical and biological sensing; medical diagnostics, and high bandwidth communications. An SGER grant would be a suitable means of supporting the work because the results would indicate whether additional research is justified, and may be used to solicit additional funding.Education and outreach activities will be carried out in combination with these research activities. These will include the participation in research of a graduate student, the incorporation of research findings into teaching, and the continued development of a series of local school outreach activities. An interactive web site (http://www.ece.udel.edu/~kolodzey/terahertztools/terahertztools.htm) will be designed suitable for senior high school or freshman college students, which will illustrate the properties of the TeraHertz frequencies, and allow students to explore terahertz absorption and reflectivity phenomena.