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

技术说明：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，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，该研究项目的总体目标是了解和控制薄二硫化铁薄膜的电子特性，以便能够制造同质结p-n太阳能电池。除了了解电子传输机制，研究活动的重点是通过执行硫化学计量和替代掺杂对二硫化铁电子性质的影响的详细和系统的检查，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膜的非原位硫化，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，旨在提供有关合成条件对薄膜性能，特别是对载流子密度和迁移率的影响的反馈和指导。非技术描述：用廉价的、可再生的太阳能电池实现可持续的太阳能-电能转换，丰富和无毒的材料是二十一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，但没有一种能够满足所有这些要求。黄铁矿结构的二硫化铁已被公认为是一种可持续材料，具有满足这些标准的巨大潜力，可替代当前技术中使用的关键材料。然而，尚未实现对这种材料的电子性质的控制，这是高效太阳能电池所需的。该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科学博物馆的互动，通过指导本科生，特别是那些来自代表性不足的群体，通过指导高中教师为他们的教室开发科学内容，并通过创建和交付有关可持续材料和化学的互动演示，旨在补充八年级的科学课程明尼阿波利斯公立学校系统

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.