SusChEM: Synthesis and Characterization of Pyrite Thin Films - Towards Sustainable Photovoltaics

技术描述：了解和控制黄铁矿二硫化铁薄膜中的掺杂是一项重大挑战，它将对实现可持续、廉价、高效的薄膜太阳能电池技术产生重大影响。为此，本研究项目的首要目标是了解和控制薄的二硫化铁薄膜的电子性质，以使同质结p-n太阳能电池的制造成为可能。除了了解电子输运机制外，研究活动还侧重于通过详细和系统地研究硫化学计量比和替代掺杂对二硫化铁电子性质的影响来建立对载流子类型和密度的控制。研究小组使用反应溅射和铁薄膜的异地硫化以及单晶生长来合成二硫化铁。薄膜和晶体合成的系统研究伴随着一系列互补的表征技术，旨在就合成条件对薄膜性能的影响，特别是对载流子密度和迁移率的影响提供反馈和指导。非技术描述：利用廉价、丰富和无毒材料制成的太阳能电池实现可持续的太阳能到电能转换是21世纪最具挑战性的问题之一。虽然主导当前太阳能电池市场的材料都具有独特的优势，但没有一种材料能够满足所有这些要求。黄铁矿结构的二硫化铁被认为是一种可持续发展的材料，具有很大的潜力来满足这些标准，取代目前技术中使用的关键材料。然而，对这种材料的电子性能的控制还没有实现，这是高效太阳能电池所必需的。本研究项目旨在利用多种合成和加工策略来实现对二硫化铁电子性质的前所未有的控制。这项研究通过与明尼苏达州科学博物馆的互动，通过指导本科生，特别是来自代表不足群体的本科生，通过指导高中教师为其课堂开发科学内容，以及通过创建和提供旨在加强明尼阿波利斯公立学校系统八年级科学课程的可持续材料和化学的互动演示，将这项研究纳入外联和教育活动。

Technical Description: Understanding and controlling doping in pyrite iron disulfide films is a major challenge that would have significant impact towards realization of a sustainable, inexpensive, high-efficiency thin-film solar cell technology. To this end, the overarching goal of this research project is to understand and control the electronic properties of thin iron disulfide films to such an extent that fabrication of homojunction p-n solar cells is enabled. In addition to understanding electronic transport mechanisms, the research activities focus on establishing control over the charge carrier type and density by executing a detailed and systematic examination of the influence of sulfur stoichiometry and substitutional doping on the electronic properties of iron disulfide. The research team uses reactive sputtering and ex-situ sulfidation of iron films, as well as single crystal growth, to synthesize iron disulfide. The systematic research of film and crystal synthesis is accompanied by a battery of complementary characterization techniques designed to provide feedback and guidance on the effects of synthesis conditions on film properties and, in particular, on carrier densities and mobilities.Non-technical Description: Achieving sustainable solar-to-electric energy conversion with solar cells made from inexpensive, abundant and non-toxic materials is one of the most challenging problems of the twenty-first century. While the materials dominating the current solar cell market each offer unique advantages, none are able to satisfy all of these requirements. Pyrite structure iron disulfide has been acknowledged as a sustainable material with great potential to satisfy these criteria, replacing critical materials used in the current technologies. However, control over the electronic properties of this material, which is required for efficient solar cells, has not yet been achieved. This research project aims to utilize multiple synthesis and processing strategies to achieve unprecedented control over the electronic properties in iron disulfide. This research is integrated into outreach and educational activities through interactions with the Science Museum of Minnesota, via mentoring of undergraduate students, particularly those from under-represented groups, via mentoring of high school teachers for developing science content for their classrooms, and through creation and delivery of an interactive presentation on Sustainable Materials and Chemistry designed to augment the science curriculum in the eighth grade Minneapolis Public Schools system.