SOLAR Optical Hyperdoping: Transforming Semiconductor Band Structure for Solar Energy Harvesting

Harvard University, Cambridge MA

Investigators

Abstract

TECHNICAL SUMMARY: The goal of this research project is to explore new methods to alter electronic band structure and therefore the optical properties of semiconductor materials so as to transform them into more efficient solar energy converters. The electronic band structure will be modified by optical hyperdoping via femtosecond laser irradiation in the presence of various gases. This process leads to higher levels of doping than are possible using other methods. To better understand and optimize the dynamics of optical hyperdoping, the team will develop new mathematical tools for modeling the hyperdoping process, focusing on the quantum mechanics associated with the unusual band structure, as well as methods for understanding and controlling the non-equilibrium process itself. The multidisciplinary team of PIs will integrate expertise in mathematics and continuum modeling of optical hyperdoping, theoretical chemistry and modeling at the quantum level, materials science of optoelectronic materials, and chemistry of surfaces and interfaces to make a concerted attack on creating and understanding new materials with transformative potential and broader impacts. NON-TECHNICAL SUMMARY: Meeting the challenge of harvesting solar energy with Earth-abundant materials such as Si and TiO2 require transformative approaches to increase efficiency, lower manufacturing cost, and reduce material requirements. While these materials have been widely studied, a multidisciplinary team from Harvard University brings a new approach to modifying the properties of semiconductors so as to open the door to more efficient solar cells. In addition, the multidisciplinary nature of the research provides unique training for students and postdocs involved in the project, with a synergistic experimental program combining materials science and chemistry, intimately coupled to a theoretical program combining mathematical analysis of the materials processes and quantum mechanical calculations of the band structure. This project is co-funded by the Divisions of Chemistry, Materials Research, and Mathematical Sciences.