STTR Phase I: High Efficiency Thin-film Photovoltaics on Low-cost Substrates by Layer Transfer

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该小企业技术转让第一阶段项目将应用高纵横比，纳米级，柱状和晶体硅结构作为模板，在低成本柔性衬底上高质量生长薄膜GaAs太阳能电池。亚10纳米硅种子层，预计将促进低缺陷密度GaAs薄膜的生长。纳米尺度结构的纵横比也用作用于去除完成的GaAs太阳能电池的牺牲层。在纳米级硅结构上外延生长GaAs薄膜和表征将在新墨西哥州大学高技术中心进行。成功的第一阶段STTR研究将导致商业化的高效率（~ 20%），灵活的太阳能电池的应用范围广泛的陆地和空间环境。硅的多次衬底重复使用和固有的大面积处理能力将导致显着的成本降低。高质量的异质外延GaAs在Si上的生长一直是一个激烈的研究课题。由于其直接带隙，GaAs对于许多光电子应用具有吸引力，并且其与Si基微电子的集成一直是一个珍视的目标。与Si的晶格和热膨胀失配使得难以生长良好的器件质量层。我们最近已经证明，随着Si籽晶尺寸减小到100 nm尺寸以下，异质外延生长的质量迅速提高。纳米级硅结构的形成，使用低成本，大面积的方法的基础上，传统的集成电路处理方法。成功的研究工作将导致光伏发电成本的降低，并提高薄膜光伏在陆地和空间环境中的适用性，因为与竞争的薄膜太阳能电池相比，GaAs薄膜太阳能电池不会受到光诱导性能下降的影响。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This Small Business Technology Transfer Phase I project will apply high aspect ratio, nm-scale, columnar, and crystalline Si structures as templates for high-quality growth of thin-film GaAs solar cells on low-cost flexible substrates. Sub-10-nm Si seed layers are expected to facilitate growth of low-defect density GaAs films. The aspect ratio of nm-scale structures also serve as sacrificial layers for removal of completed GaAs solar cell. Epitaxial growth and characterization of GaAs films on nm-scale Si structures will be carried out at the Center for High Technology at the University of New Mexico. Successful phase I STTR research will lead to commercialization of high (~ 20 %) efficient, flexible solar cells for applications in a wide range of terrestrial and space environments. Multiple substrate re-use and inherent large area processing capability of Si will result in significant cost reductions.High quality heteroepitaxial GaAs growth on Si has been a subject of intense research. Due to its direct bandgap, GaAs is attractive for a number of optoelectronics applications and its integration with Si-based microelectronics has been a cherished goal. The lattice and thermal expansion mismatches with Si make it difficult to grow good device quality layers. We have recently demonstrated as the Si seed dimension is reduced below 100 nm dimensions, the quality of heteroepitaxial growth increases rapidly. The nm-scale Si structures are formed using low-cost, large area methods based on conventional integrated circuit processing methods. Successful research effort will lead to reduction in PV generation costs, and enhanced applicability of thin-film PV in terrestrial and space environments because in contrast with competing thin-film solar cells, GaAs thin-film solar cells will not suffer from light-induced performance degradation.