Solar cells can convert sunlight into electricity, providing a clean and renewable energy source. This is of very high priority given the continually diminishing resources and rising prices of fossil fuels and degrading global environment from fossil fuel burning. The project addresses fundamental understanding and improvement of the stability of perovskite solar cells, a strong candidate important for a renewable and environmentally friendly energy source. It can be expected that the research activities will result in new device structures and performance enhancements of perovskite solar cells. Efforts will be made to bring science and technology to real products that impact the society. A major part of the program will be educating and training graduate and undergraduate students through interdisciplinary research in advanced materials and devices and in materials surface/interface characterization. A strong focus of the program is on increasing participation of scientific research by under-represented minorities as well as women at all levels and providing early exposure of research to middle and high school students through programs at University of Rochester and University of North Carolina. Perovskite solar cell demonstration kits will be developed for high school students, and presentations to the community at large to show the usefulness of perovskite solar cells.
There have been unexpected breakthroughs and rapid evolution in organometal trihalide perovskite materials for high-performance optoelectronic devices. Although the power efficiency of hybrid perovskite solar cells has already reached over 23% in the laboratory, the stability of the materials remains a critical issue. The goal of the project is to study the stability of organometal trihalide perovskites using surface analytical techniques, to resolve the fundamental issues and challenges regarding the stability of these materials, and to improve the stability through materials synthesis and interface engineering. The surface analytical techniques include, but are not limited to, angle-resolved photoelectron spectroscopy, ultraviolet and x-ray photoelectron spectroscopy, inverse photoemission spectroscopy, low energy electron diffraction, scanning tunneling microscopy, atomic force microscopy, and scanning electron microscopy. The scope and approaches of the research include: 1) the stability and degradation mechanisms of different organometal trihalide perovskites, including the effects of environmental factors, light illumination, and device operation; 2) the stability improvement of the interfaces, including minimizing interface reaction, ion migration, and providing protection of the perovskites from environmental detrimental factors; 3) the passivation and stabilization of grain boundaries, including neutralizing charge trapping defects and minimizing impurity migration along the grain boundaries.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
