Surface Analytical Investigation on Organometal Trihalide Perovskite

首席研究员：高永丽编号：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的材料？的能量，并将其光子转换为电子，这一过程称为光子学。 寻找最佳光伏材料是太阳能电池研究的一个活跃领域。 最近，出现了一类令人兴奋的新型光伏材料，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，目前拥有超过15%的太阳能转换效率。 然而，这些材料如此有效的原因尚不清楚。 该项目的总体目标是通过使用高灵敏度技术来探测材料表面和界面而不破坏材料本身，从而从根本上了解钙钛矿太阳能电池材料的光伏性能起源。 这一基本认识可用于推进太阳能电池应用钙钛矿材料的开发。 该项目活动将培训研究生和本科生掌握材料表面表征的最新技术。 罗切斯特大学的现有项目将用于为高中女生提供有机电子学的实验室图尔斯参观、简短讲座和动手体验，以激发对STEM领域的兴趣。 技术说明近年来，有机金属钙钛矿已成为地球上储量丰富的新型光伏材料，其太阳能转换效率超过15%，并且具有低制造成本的潜力。 该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起源。 拟议的研究将研究电子结构，界面形成，载流子弛豫动力学，以及影响这些材料在空气中的稳定性的因素，通过各种技术，其中包括紫外和X射线光电子能谱，逆光电子能谱和时间分辨双光子光电子能谱。将使用低能电子衍射、扫描隧道显微镜和原子力显微镜来表征表面结构和形态。 最后，钙钛矿薄膜器件结构将在真空下原位制备和表征，然后直接转移到表面分析工具，以确定界面结构如何变化。 这种综合方法将全面描述钙钛矿太阳能电池材料的电子结构和界面特性及其与光伏性能的相关性。该项目活动将培训研究生和本科生掌握材料表面表征的最新技术。 罗切斯特大学的现有项目将用于为高中女生提供有机电子学的实验室图尔斯参观、简短讲座和动手体验，以激发对STEM领域的兴趣。 将开发坚固的钙钛矿太阳能电池演示套件，供高中学生使用。

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.