BaSnO3 as a Transparent Mixed Ionic-Electronic Conducting Material - Utilizing Novel In Situ Methods to Advance Understanding of Structure-Processing-Property Relations

非技术描述：氧化钡锡（BaSnO3）是一种非凡的新材料，是太阳能电池和显示技术中急需的低丰度但目前至关重要的铟基透明电极的替代品。此外，这种材料经过适当的化学修饰后，非常适合作为模型系统，用于研究缺陷在影响混合离子-电子导电电极性能方面的作用，例如，固体氧化物燃料电池，以其高化学到电能的转换效率而著称。新的原位高温测量方法被用于探索缺陷的形成和传输以及微观结构对氧化钡锡的电学、电化学和光学性能的影响，以及探索和优化其薄膜生长。所获得的见解将有助于为太阳能和燃料电池应用开发更坚固的透明和混合导电电极，并通常提供关键的见解，了解生长参数的变化如何影响功能薄膜的化学和形态，从而影响其性能。一个科学，技术，工程和数学（STEM）项目为基础的课程，从内城和郊区的学校，以少数民族和女学生为重点，开发和实施，与一名高中教师/教师培训教员一起，在清洁能源和环境技术的主题，以提高他们对紧迫的全球问题的科学理解，并激励他们考虑STEM职业。研究实习，提供给来自科学和工程学科的本科生，为他们提供体验实际研究的机会。技术细节：受体和供体掺杂的氧化钡锡的电学、电化学和光学行为，是太阳能电池中急需的低丰度透明电极替代品的主要候选者，正在广泛的温度和氧分压范围内进行研究。新的原位表征方法允许开发供体和受体掺杂材料的定量缺陷和输运模型，这是它们作为透明或混合离子电子导电材料实际应用的重要步骤。一种监测薄膜原位生长的新方法将允许有效地优化薄膜的生长、微观结构和性能，并最终实现所有物理气相沉积薄膜的沉积条件。另外的重点放在量化和解释晶界对透明导电钡锡氧化物的有效电子迁移率的显著影响。这种研究方法为指定的研究生提供了学习前沿实验和建模技术的绝佳机会，并对材料研究如何解决社会的主要挑战有了更广泛的了解。

NON-TECHNICAL DESCRIPTION: Barium tin oxide (BaSnO3) is a remarkable new material and a prime candidate for the much-needed replacement of low-abundance, but presently critical indium-based transparent electrodes for solar cell and display technologies. Additionally, this material, when appropriately chemically modified, is well-suited to serve as a model system for studying the role of defects in influencing the performance of mixed ionic-electronic conducting electrodes in, for example, solid oxide fuel cells, noted for their high chemical-to-electrical energy conversion efficiencies. Novel in situ high temperature measurements are being employed to explore defect formation and transport and the effects of microstructure on the electrical, electrochemical and optical properties of barium tin oxide, as well as exploring and optimizing its thin film growth. Insights gained will aid in developing more robust transparent and mixed conductive electrodes for solar and fuel cell applications and generally provide critical insights into how variations in growth parameters impact the chemistry and morphology of functional thin films and thereby their properties. A science, technology, engineering & mathematics (STEM) project-based course for high school students, drawn from both inner city and suburban schools, with a focus on minority and female students, is developed and implemented, in conjunction with a high school teacher/ teacher-training faculty member, on the topic of clean energy and environmental technologies, to improve their scientific understanding of pressing global issues and stimulate them to consider STEM careers. Research internships, are offered to undergraduate students from the science and engineering disciplines, to provide them with the opportunity to experience research in action. TECHNICAL DETAILS: The electrical, electrochemical and optical behavior of acceptor- and donor-doped barium tin oxide, a prime candidate for the much needed replacement of low-abundance transparent electrodes for solar cells, are being investigated over a wide range of temperature and oxygen partial pressure. Novel in situ characterization methods allow for development of quantitative defect and transport models for donor- and acceptor-doped materials, vital steps towards their practical utilization as a transparent or mixed ionic-electronic conducting materials. A novel method for monitoring film growth in situ will allow for the efficient optimization of film growth, microstructure and properties of these, and ultimately all physical vapor deposited films, with respect to deposition conditions. Additional focus is placed on quantifying and explaining the significant impact of grain boundaries on the effective electron mobility of transparent conductive barium tin oxide. This research approach provides an excellent opportunity for the designated graduate student to learn cutting edge experimental and modeling techniques and gain a broader appreciation of how materials research can address society's major challenges.