Nanostructured Copper Sulfide Alloys for Solar Energy Conversion

技术：本项目的科学目标是了解和控制原子层沉积的硫化铜半导体在介孔氧化物模板上的薄膜生长和渗透。本研究的关键是使用原子层沉积来控制原子分辨率下的材料生长，以获得遵循纳米结构氧化物轮廓的超薄保形硫化铜基半导体薄膜，以及一套表征工具来了解薄膜生长机制和所得材料性能。工业合作伙伴Air Products and Chemicals， Inc.提供定制的金属有机前体，这使得对材料化学计量和相位的控制前所未有，这是以前尝试利用cu基材料进行太阳能转换的主要问题。利用高分辨率电子显微镜和光学研究方法，研究了原子层沉积前驱体在介孔纳米颗粒和纳米线模板表面的保形覆盖能力与材料加工条件的关系。重点放在理解和控制材料的相位和均匀性，陷阱态密度，结构缺陷和电子结构，通过x射线同步加速器测量，光热偏转光谱，以及材料和器件的传输特性进行评估。非技术：该项目涉及材料科学主题领域的基础研究问题，具有高技术相关性。它有助于开发基于丰富，无毒元素的半导体材料，可用于太阳能转换。这些学院计划通过与当地为拉美裔服务的社区学院和组织合作，扩大他们在培养代表性不足的物理系学生方面的成功记录。这项工作的大部分是在UCSC高级研究实验室进行的，为学生提供了接触NASA和工业合作者的机会。

Technical: The scientific goal of this project is to understand and control film growth and penetration of atomic layer deposited copper sulfide semiconductors onto mesoporous oxide templates. Critical to this research is use of atomic layer deposition to control the material growth at atomic resolutions to achieve ultrathin conformal copper sulfide-based semiconducting films that follow the contours of nanostructured oxides, and a suite of characterization tools to understand the mechanisms for film growth and resulting materials properties. The industrial partner, Air Products and Chemicals, Inc., provides custom metal organic precursors, which enable unprecedented control over material stoichiometry and phase, a major issue with previous attempts to utilize Cu-based materials for solar energy conversion. The ability of the atomic layer deposition precursors to conformally coat the mesoporous nanoparticle and nanowire templates as a function of material processing conditions is studied using high resolution electron microscopy and optical studies. Focus is placed on understanding and controlling the material phase and homogeneity, trap state density, structural defects, and electronic structure as evaluated by X-ray synchrotron measurements, photothermal deflection spectroscopy, and the transport properties of materials and devices.Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. It contributes to the development of semiconductor materials based on abundant, non-toxic elements that could be used for solar energy conversion. The PIs plan to expand their successful track record of training underrepresented physics students through collaborations with local Hispanic-serving community colleges and organizations. Much of this work is performed at the UCSC Advanced Studies Laboratory, providing students exposure to both NASA and industrial collaborators.