Electronic Band Structure Investigations of Complex Multi-Component Oxides for Photovoltaic Applications

用于光伏应用的复杂多组分氧化物的电子能带结构研究

• 批准号: 0705626
• 负责人: Julia Medvedeva
• 金额: $ 20.7万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-15 至 2010-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0705626&HistoricalAwards=false
• 关键词: Electronic; Band; Structure; Investigations; Complex

TECHNICAL SUMMARY:This award supports computational and theoretical research and education that aims to use electronic structure methods to aid in the understanding and discovery of materials with properties that are desirable for applications in photovoltaic systems. Next generation strategies for the development of light-weight solar cells rely upon a semiconducting light-absorbing material that is grown on top of transparent conducting oxide substrate. The substrate acts as window in the resulting solar cells but also provides a secondary role as the ohmic contact that allows for transport of the photogenerated charge carriers from the light absorbing semiconductor. This project employs density-functional-theory-based computer simulations to study and predict the structural, electronic and optical properties of complex multi-component oxides which form a layered structure with a stoichiometry R2O3(MO)m . Here, R = trivalent ion, M = divalent ion, and m=integer. The motivation is to identify candidates for transparent conducting hosts which are appropriate for photovoltaic applications. In this regard, it is necessary to determine which selection of trivalent and divalent ions lead to intrinsically doped materials that provide a maximal conductivity without sacrificing the need for optical transmission. In addition to considering a means for maximizing the number of charge carriers this research addresses the possibility of optimizing carrier mobilities rather than carrier concentration. The systems under study span a large range of structural and combinatorial peculiarities of complex multicomponent oxides and offer the possibility to incorporate main group metal oxides such as CaO, Al2O3 and SiO2 in place of the traditional In2O3, ZnO and SnO2 transparent conducting oxides.The unique predictive power of the state-of-the-art density functional methods employed in this project provide fundamental understanding of the underlying physical phenomena, the system behavior, as well as novel and hidden functionalities in the proposed materials and will stimulate further theoretical and experimental efforts. This project may have impact across the disciplines of physics, chemistry, materials scientists and engineering. This project supports efforts to attract and mentor women pursuing advanced degrees in the sciences. NON-TECHNICAL SUMMARY:This award supports computational and theoretical research and education that aims to use computers and theory to aid in the understanding and discovery of materials with properties that are desirable for applications in photovoltaic systems. One of the current problems related to development of the next generation of lighter-weight economically viable solar cells is finding materials that have a seemingly contradictory combination of properties. They should at once allow sunlight to pass through but also be able to conduct electrically. This research uses sophisticated computational methods for optimizing transparent conducting oxide materials for this function. An additional emphasis is on determining how to construct transparent conducting oxides from the metal atoms that are more abundant and safer for the environment. This research project helps to keep America competitive and contributes to technologies that hold promise for sustainable energy production. This project also pushes toward realizing the dream of using computers and theory to design materials with desired properties knowing only the identity of the constituent atoms.In parallel with the research are educational initiatives at the high school, undergraduate and graduate level and an effort to attract and mentor women pursuing advanced degrees in the sciences.

该奖项支持计算和理论研究和教育，旨在使用电子结构方法来帮助理解和发现具有光伏系统应用所需特性的材料。下一代开发轻质太阳能电池的策略依赖于在透明导电氧化物衬底上生长的半导体光吸收材料。 衬底在所得太阳能电池中充当窗口，但也提供作为欧姆接触的次要作用，其允许从光吸收半导体传输光生电荷载流子。 该项目采用基于密度泛函理论的计算机模拟来研究和预测复杂多组分氧化物的结构，电子和光学性质，这些氧化物形成具有化学计量比R2O3（MO）m的层状结构。这里，R =三价离子，M =二价离子，m=整数。 其动机是确定候选人的透明导电主机是适合光伏应用。 在这方面，有必要确定三价和二价离子的哪种选择导致提供最大电导率而不牺牲对光学传输的需要的本征掺杂材料。 除了考虑最大化电荷载流子数量的方法外，本研究还讨论了优化载流子迁移率而不是载流子浓度的可能性。 所研究的体系涵盖了复杂多组分氧化物的大范围结构和组合特性，并提供了引入主族金属氧化物如CaO、Al 2 O 3和SiO 2代替传统的In 2 O 3的可能性，ZnO和SnO2透明导电氧化物。本项目中采用的密度泛函方法提供了对基本物理现象，系统行为，以及所提出的材料中的新颖和隐藏的功能，并将激发进一步的理论和实验努力。该项目可能会对物理学，化学，材料科学家和工程学等学科产生影响。 该项目支持努力吸引和指导攻读科学高级学位的妇女。非技术总结：该奖项支持计算和理论研究和教育，旨在使用计算机和理论来帮助理解和发现具有光伏系统应用所需特性的材料。当前与开发下一代更轻的经济上可行的太阳能电池相关的问题之一是找到具有看似矛盾的性质组合的材料。它们应该能让太阳光通过，而且还能导电。 这项研究使用复杂的计算方法来优化透明导电氧化物材料的这种功能。另一个重点是确定如何从对环境更丰富和更安全的金属原子中构建透明导电氧化物。该研究项目有助于保持美国的竞争力，并有助于实现可持续能源生产的技术。该项目还推动实现利用计算机和理论设计具有所需特性的材料的梦想，只知道组成原子的身份，与研究同时进行的是高中、本科和研究生一级的教育举措，并努力吸引和指导攻读科学高级学位的妇女。