Surface Analytical Investigation on Organometal Trihalide Perovskite

主要研究人员：永利高编号：1437656太阳代表着地球上最丰富的潜在无污染能源。用于发电的太阳能电池需要吸收太阳能的材料--S，并将其光子转化为电子，这一过程被称为光伏。寻找最佳的光伏材料是太阳能电池研究的一个活跃领域。最近，一类令人兴奋的新的光伏材料出现了，称为有机金属钙钛矿。这些材料很有前途，因为它们生产成本低，使用地壳中丰富的元素和材料，目前具有超过15%的太阳能转换效率。然而，这些材料工作得如此之好的原因并不真正清楚。该项目的总体目标是通过使用高灵敏度的技术在不破坏材料本身的情况下探测材料表面和界面，从而从根本上了解钙钛矿型太阳能电池材料的光伏性能来源。这一基本认识可以用来推动太阳能电池用钙钛矿材料的发展。项目活动将对研究生和本科生进行材料表面表征的最新技术培训。罗切斯特大学现有的课程将用于为高中女生提供有机电子领域的实验室参观、短期讲座和实践体验，以激发对STEM领域的兴趣。坚固耐用的钙钛矿太阳能电池演示套件将被开发出来供高中生使用。技术描述最近，有机金属钙钛矿已经成为一种令人兴奋的富含地球的新型光伏材料，太阳能转换效率超过15%，并且具有制造成本低的潜力。这个项目的总体目标是使用一系列表面分析工具，从根本上了解有机金属三卤化物钙钛矿材料光伏性能的来源。这项研究将通过各种技术来研究这些材料在空气中的电子结构、界面形成、载流子弛豫动力学以及影响其稳定性的因素，包括紫外和X射线光电子能谱、反向光电子能谱和时间分辨双光子光电子能谱。利用低能电子衍射、扫描隧道显微镜和原子力显微镜对薄膜的表面结构和形貌进行了表征。最后，在真空下原位制备和表征钙钛矿型薄膜器件结构，然后直接转移到表面分析工具，以确定界面结构是如何变化的。这一综合方法将全面描述钙钛矿型太阳能电池材料的电子结构和界面性质，以及它们与光伏性能的关系。项目活动将对研究生和本科生进行材料表面表征的最新技术培训。罗切斯特大学现有的课程将用于为高中女生提供有机电子领域的实验室参观、短期讲座和实践体验，以激发对STEM领域的兴趣。坚固的钙钛矿型太阳能电池演示套件将被开发出来，供高中生使用。

Principal Investigator: Yongli GaoNumber: 1437656The sun represents the most abundant potential source of pollution-free energy on earth. Solar cells for producing electricity require materials that absorb the sun?s energy and convert its photons to electrons, a process called photovoltaics. The search for the best photovoltaic material is an active area of solar cell research. Recently, an exciting new class of photovoltaic materials called organo-metal perovskites has emerged. These materials are promising because they have low production cost, use elements and materials abundant in the earth's crust, and currently possess solar energy conversion efficiencies of over 15%. However, the reasons why these materials work so well is not really known. The overall goal of this project is to gain a fundamental understanding of the origins of photovoltaic performance in perovskite based solar cell materials by using highly sensitive techniques to probe the material surfaces and interfaces without destroying the material itself. This fundamental understanding can be used to advance the development of perovskite materials for solar cell applications. The project activities will train graduate and undergraduate students in state of the art techniques for surface characterization of materials. Existing programs at the University of Rochester will be used to provide lab tours, short lectures, and hand-on experiences for high school girls in organic electronics to stimulate interest in STEM fields. Robust perovskite solar cell demonstration kits will be developed for use by high school students.Technical DescriptionRecently, organo-metal perovskites have emerged as an exciting new class of earth-abundant photovoltaic materials, with solar energy conversion efficiencies exceeding 15% and potential for low manufacturing cost. The overall goal of this project is to use an array of surface analysis tools to gain a fundamental understanding of origins of photovoltaic performance of organometal trihalide perovskite materials. The proposed research will study the electronic structure, interface formation, carrier relaxation dynamics, and factors affecting the stability of these materials in air, through variety of techniques, which include ultraviolet and x-ray photoelectron spectroscopy, inverse photoemission spectroscopy, and time-resolved 2-photon photoemission spectroscopy. The surface structure and morphology will be characterized using low energy electron diffraction, scanning tunneling microscopy and atomic force microscopy. Finally, perovskite thin film device structures will be prepared and characterized in situ under vacuum and then transferred directly to the surface analytical tools to determine how interface structures change. This integrated approach will provide a comprehensive description of the electronic structure and interface properties of perovskite based solar cell materials and their correlation to photovoltaic performance. The project activities will train graduate and undergraduate students in state of the art techniques for surface characterization of materials. Existing programs at the University of Rochester will be used to provide lab tours, short lectures, and hand-on experiences for high school girls in organic electronics to stimulate interest in STEM fields. Robust perovskite solar cell demonstration kits will be developed for use by high school students.