Project Details

Description

Justification For Supplement In this supplemental proposal, we request funding to involve two REU (Research Experience for Undergraduate) students in our NSF-funded research project focused on the growth of highquality pyrite thin films for photovoltaic (PV) applications. We developed a new method to produce single-phase, stoichiometric, and epitaxial pyrite thin films under the parent grant. The unexpected efficiency of the growth process has allowed us to produce the large number of films required to optimize the properties of undoped and doped material. We would like to capitalize on the opportunity provided. Our project would greatly benefit from having undergraduate students assist in the characterization of the material. We believe this will be very beneficial to the project and will be excellent hands-on training for undergraduate materials science and engineering students. It will give the students an opportunity to explore exciting aspects of science with a focus on the fabrication and characterization of semiconductor thin films for solar cell technology. We expect that this experience will increase the students scientific knowledge and understanding and raise their interest in science and engineering. Summary of Proposed Work In this supplemental proposal, we seek funds to provide stipends for two REU students so that they can be involved in our NSF-funded research project focused on the growth of highquality pyrite thin films. We have developed a new method to produce single phase, stoichiometric and epitaxial pyrite thin films.1-2 We believe this material will be useful for largearea low-cost photovoltaic (PV) applications with further optimization. The initial success of the project has increased the workload and the project would greatly benefit from having the undergraduate students assist in the characterization of the material. Involvement in this research project would allow the students to extend their knowledge beyond the classroom setting and to develop the skills necessary to address real world challenges. We anticipate each student would work on the order of 7-10 hours per week. Over the course of the year, we will train the students to measure carrier concentration and mobility using Hall effect measurements, carrier lifetime using time-resolved photoconductivity measurements, and pyrite structural quality using X-ray diffraction measurements. In addition to providing important information for our ongoing effort to optimize the quality of undoped and doped pyrite films, we also expect this to be a productive, educational, and hopefully enjoyable, experience for the undergraduate students. Project Background The growth of high-quality pyrite thin films is challenging, largely due to the high sulfur vapor pressure at the temperatures required to attain epitaxy. Growth at too low temperature results in poor structural and electrical quality, and growth at too high temperatures results in the formation of sulfur-deficient non-stoichiometric pyrite or other phases. Under the NSF parent grant, we developed a new layer-by-layer growth technique using sequential evaporation of Fe in high-vacuum followed by sulfidation at pressures of 1 Torr and higher onto a heated substrate. This patented technique allows us to produce single phase, stoichiometric and epitaxial pyrite materials for the first time from the inexpensive elemental Fe and S. Optimization of the electrical, optical and structural properties of undoped-films is underway by varying the substrate
StatusFinished
Effective start/end date9/1/118/31/14

Funding

  • National Science Foundation (NSF): $307,698.00

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