This award supports computational and theoretical research and education that aims to use electronic structure methods to aid in the understanding and discovery of materials with properties that are desirable for applications in photovoltaic systems.
Next generation strategies for the development of light-weight solar cells rely upon a semiconducting light-absorbing material that is grown on top of transparent conducting oxide substrate. The substrate acts as window in the resulting solar cells but also provides a secondary role as the ohmic contact that allows for transport of the photogenerated charge carriers from the light absorbing semiconductor. This project employs density-functional-theory-based computer simulations to study and predict the structural, electronic and optical properties of complex multi-component oxides which form a layered structure with a stoichiometry R2O3(MO)m . Here, R = trivalent ion, M = divalent ion, and m=integer. The motivation is to identify candidates for transparent conducting hosts which are appropriate for photovoltaic applications. In this regard, it is necessary to determine which selection of trivalent and divalent ions lead to intrinsically doped materials that provide a maximal conductivity without sacrificing the need for optical transmission. In addition to considering a means for maximizing the number of charge carriers this research addresses the possibility of optimizing carrier mobilities rather than carrier concentration. The systems under study span a large range of structural and combinatorial peculiarities of complex multicomponent oxides and offer the possibility to incorporate main group metal oxides such as CaO, Al2O3 and SiO2 in place of the traditional In2O3, ZnO and SnO2 transparent conducting oxides. The unique predictive power of the state-of-the-art density functional methods employed in this project provide fundamental understanding of the underlying physical phenomena, the system behavior, as well as novel and hidden functionalities in the proposed materials and will stimulate further theoretical and experimental efforts.
This project may have impact across the disciplines of physics, chemistry, materials scientists and engineering. This project supports efforts to attract and mentor women pursuing advanced degrees in the sciences.
NON-TECHNICAL SUMMARY:
This award supports computational and theoretical research and education that aims to use computers and theory to aid in the understanding and discovery of materials with properties that are desirable for applications in photovoltaic systems.
One of the current problems related to development of the next generation of lighter-weight economically viable solar cells is finding materials that have a seemingly contradictory combination of properties. They should at once allow sunlight to pass through but also be able to conduct electrically. This research uses sophisticated computational methods for optimizing transparent conducting oxide materials for this function. An additional emphasis is on determining how to construct transparent conducting oxides from the metal atoms that are more abundant and safer for the environment.
This research project helps to keep America competitive and contributes to technologies that hold promise for sustainable energy production. This project also pushes toward realizing the dream of using computers and theory to design materials with desired properties knowing only the identity of the constituent atoms.
In parallel with the research are educational initiatives at the high school, undergraduate and graduate level and an effort to attract and mentor women pursuing advanced degrees in the sciences.
