Exceeding the Limit in Solar Energy Conversion with Exciton Fission

利用激子裂变突破太阳能转换极限

• 批准号: 1207254
• 负责人: Xiaoyang Zhu
• 金额: $ 46.61万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207254&HistoricalAwards=false
• 关键词: Exceeding; Limit; Solar; Energy; Conversion

Technical Description: The maximum solar-to-electric power conversion efficiency of a conventional solar cell is determined by the Shockley-Queisser limit of about 31%, which comes from the loss of excess energies in hot electrons and holes created from the absorption of photons with energies above the semiconductor bandgap. A viable approach to exceed this limit is to create two electron-hole pairs from the absorption of one photon in a process called exciton fission. Exciton fission has attracted renewed interest because of the great potential of designing molecules for optimal fission yields. To successfully implement exciton fission for solar energy conversion, the PI and his students are addressing three fundamental questions: 1) What are the physical principles that govern optimal exciton fission yield? 2) How does efficient energy transfer occur at organic semiconductor interfaces for singlet and triplet excitons? 3) What is the best strategy to harvest multiple carriers from singlet fission? The research team uses model organic semiconductors with varying energetics or with different degrees of crystallinity to address the roles of coherent electronic coupling vs. thermal activation and to probe the effect of electronic delocalization in exciton fission. The team also uses model organic semiconductor interfaces to probe energy transfer and charge transfer. All these experiments serve to establish fundamental principles in the implementation of exciton fission for efficient solar energy conversion.Non-technical Description: In addition to new scientific discoveries and developments that will form the foundation of future solar energy conversion technologies with much improved efficiency, this project also provides an excellent educational opportunity for the training of the future high-tech workforce. The educational and outreach activities consist of three major parts: 1) supervising K-12 students in solar energy research within the Welch Foundation Summer Scholar program and as a member of the West Lake High school's Independent Study Mentorship program; 2) collaboration with emerging solar industries, in particular, with Konarka Technologies, Inc., a pioneer and leader in polymer based photovoltaics; and 3) developing new undergraduate curriculum on solar energy, which serves to prepare students for the emerging job market in the solar energy economy.

技术描述：传统太阳能电池的最大太阳能转换效率由冲击式标题限制约为31％，这是由于热电子中过量能量的损失以及由在半导体带上方的能量吸收的光子吸收而产生的孔中。超过此限制的可行方法是，在称为激子裂变的过程中，从一个光子的吸收中创建两个电子孔对。激子裂变引起了新的兴趣，因为设计分子以达到最佳裂变产率。为了成功实施太阳能转换的激子裂变，PI和他的学生正在解决三个基本问题：1）哪些人的物理原理是最佳的激子裂变产量？ 2）如何在有机半导体界面和三重态激子的有机能量转移？ 3）从单线裂变中收获多个载体的最佳策略是什么？研究团队使用具有不同能量学或不同程度的结晶度的有机半导体模型来解决相干电子耦合与热激活的作用，并探测电子离域化在Ickiton裂变中的影响。该团队还使用模型有机半导体接口来探测能量传输和电荷传输。所有这些实验旨在建立基本原理，以实施激子裂变，以进行有效的太阳能转换。Non-technical描述：除了新的科学发现和发展外，还将构成具有大大提高效率的未来太阳能转换技术的基础，该项目还为未来高级技术培训培训提供了出色的教育机会。教育和外展活动包括三个主要部分：1）在韦尔奇基金会夏季学者计划中监督K-12学生的太阳能研究，并作为西湖高中独立学习指导计划的成员； 2）特别是与新兴的太阳能行业与基于聚合物的光伏的先驱和领导者Konarka Technologies，Inc。合作； 3）开发有关太阳能的新的本科课程，该课程为学生准备太阳能经济的新兴就业市场做好准备。