Tailored Microstructures of Inhomogeneous Composite Materials for Very Thin Optoelectronic Devices

用于超薄光电器件的非均质复合材料的定制微观结构

• 批准号: 8700592
• 负责人: Clayton Bates
• 金额: $ 20.19万
• 依托单位: Stanford 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: 1987-06-01 至 1990-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8700592&HistoricalAwards=false
• 关键词: Tailored; Microstructures; Inhomogeneous; Composite; Materials

A previous study indicated that thin films of Ag-Si and Ag- CuInSe2 composites may be produced with unique optical and good electrical transport properties and they may be used to construct optoelectronic devices with some very unusual properties. Theoretical studies of the Ag-0-Cs S-1 photocathode showed that a "tailored" Ag-0-Cs system could produce a photoelectric quantum yield (PQY) of a few percent at 1.5um, something not realized with presently existing photoemitters. In particular, Ag-polycrystalline Si composites 1um thick have been made with selective absorption peaks at 2.4, 3.0, 3.8, 4.8, 7.2 and l2um with extremely large absorption coefficients (10**3-10**4/cm-+) relative to Si at these wavelengths, in good agreement with a recently formulated dynamic effective medium approximation (DEMA) developed to describe these systems. These composites have measured Hall mobilities of 425cm2/ (volt-sec) are n-type with resistivities varying between 10**6 to 10**-3 ohm-cm depending upon the volume fraction of Ag. The effort here will be to dope these composites with well-defined p- or n- type conductivity to make them useful in constructing very thin optoelectronic devices.

先前的研究表明，Ag-Si和Ag-CuInSe2复合薄膜可以制备出具有独特的光学和电学性质的薄膜，它们可以用来构建具有一些非常特殊的性能的光电子器件。对Ag-0-Cs S-1光电阴极的理论研究表明，“量身定制”的Ag-0-Cs系统可以在1.5um产生几个百分点的光电量子产率，这是目前的光电发射体所无法实现的。特别是厚度为1um的Ag-多晶硅复合材料，在2.4，3.0，3.8，4.8，7.2和12um处有选择性吸收峰，在这些波长相对于Si有极大的吸收系数(10**3-10**4/cm-+)，这与最近提出的描述这些体系的动态有效介质近似(DEMA)很好地一致。这些复合材料的霍尔迁移率为425cm2/(伏特-秒)，是n型的，其电阻率在10**6到10**-3欧姆-厘米之间变化，这取决于银的体积分数。这里的工作将是在这些复合材料中掺杂定义明确的p型或n型导电性，使其在构建非常薄的光电子器件方面有用。