Computer Optimization and 3D Printing of Quantum Dot Solar Cells

The ability to assemble materials on the micro-to-nanometer scale continues to be an area of great scientific and technological interest. In the field of solar cells, using highly ordered arrays of nanoscale pillars as electrodes resulted in up to a 50% increase in solar cell efficiency compared to a flat electrode. Despite this success, it is challenging to predict from basic scientific principles which structures will improve photovolatic efficiency. Furthermore, current strategies for achieving structural control, such as self-assembly or etching, are extremely limited in the scope of structures that can be formed. My proposal explores exciting opportunities at the confluence of computer optimization and 3D printing to maximize efficiency of solar cells. My proposed research will first apply this dual approach to the field of Quantum Dot (QD) assemblies for photovoltaics. Quantum dots hold tremendous potential for efficient solar energy conversion, which has broad impacts for our transition towards a sustainable energy portfolio. Despite impressive recent progress, one of the largest challenges in thin film QD solar cells is the poor extraction of photo-generated charges due to lack of continuous charge collection pathways. Therefore, even if exciton generation in QDs is record breaking, until there is sufficient control over QD assemblies that allows for collection of electrons at one of the electrodes, QD photovoltaic devices will not reach their full potential. The problem of inefficient charge collection is not specific to QD solar cells, and this research will enable more efficient overall solar cell design. I initiated this research project because I saw the potential for computer optimization methods and 3D printing to vastly improve QD assemblies and their resultant photovoltaic performance. I sought out experts in these two very different fields and brought them together to collaborate on and solve this interdisciplinary problem. Both at Cornell University, Professor Hod Lipson in the Mechanical Engineering dept. is an expert in computational optimization and 3D printing, and Professor Tobias Hanrath in the Chemical Engineering dept. is an expert in QD assemblies. I will conduct my research jointly between their labs. I will use computational techniques to obtain optimized 3D structures for both the solar cell electrodes and for the QD assemblies. The best structures will be 3D printed and tested to verify the optimization methods. In the end, the optimization of structure by a combination of computer optimization and 3D printing will be broadly applicable to many technologies. More »