The objective of this program is exploring a novel mechanism of efficient charge transfer and transport using ferroelectric materials. To accomplish this goal, the proposed research will be focused on following tasks: 1) synthesis and preparation of inorganic and organic materials for light absorber and ferroelectricity, 2) device fabrication using various structure designs to take advantages from synthesized materials and 3) optical and electrical characterization as well as spectroscopic evaluation. As a transformative research, the successful outcomes will contribute to build a novel photovoltaic mechanism which can provide a major impact to overcome the obstacles in next generation solar cell.
The intellectual merit is that it can discover unexplored physics from proposed ferroelectric assisted charge transport in nanostructured solar cell. Also, the research outcomes will provide the solutions and direction for nanomaterial based photovoltaic devices. Finally, it will lead the creation of a novel technology towards new next generation photovoltaic paradigm.
The broader impacts are innovative curricular materials which emphasize nanotechnology and interdisciplinary research for the graduate students, and opportunities of research experience to the undergraduate students. The undergraduate research will focus on participation of underrepresented minority groups. Also, this program will benefit to renewable energy technology and related industry and scientific societies.
The efficiency of the solar cell can be determined by how much light energy converted to the electrical power. The electrical power is a product of the current and voltage. Therefore, it is important to increase the amount of the current and the strength of the voltage in general. However, the conventional semiconductor based solar cells always have a trade-off between the current and voltage values and the theoretical maximum efficiency is limited to around 32%. The goal of the proposed research is exploring novel photovoltaic concept and underlying fundamentals to achieve efficient next generation solar cell using new nanomaterials. We chose colloidal semiconducting nanocrystals as a light absorber to produce large current and a ferroelectric material to produce high voltage. In order to achieve low cost device production, we developed an all solution processed device fabrication method. One of the accomplishments of this research is a successful development of the synthesis method of ferroelectric lead zirconate titanate (PZT) nanoparticles with high production yield. This enabled a low temperature solution based device fabrication and we demonstrated good electrical and optical properties from the fabricated devices. The other important achievement is the observation of the enhanced photo voltage from a hybrid device using nanocrystals and PZT nanoparticles. It was a successful demonstration that shows the feasibility of a hybrid device for new power generation mechanism. We have presented our finding in 3 different international conferences such as Materials Research Society Meeting, IEEE-Photovoltaic Specialists Conference and SPIE Photonics West. And we expect to publish several journal papers. In addition, this research supported the undergraduate research involvement and the outreach program for the local high school students. This activities helped the students to have interests on Science and Technology. Finally, the research outcomes on synthesis of nanostructured materials and solution based fabrication process will enhance the understanding of the proposed photovoltaic mechanism and facilitate the development of next generation solar cells.