March 19, 2019
- A team consisting of MSE Ph.D. students Tao Zhang and Dana Dement, and their advisors Professors Russell Holmes and Vivian Ferry, has recently reported a new method that permits measurement of nanoscale energy transport in a working solar cell. Many emerging thin film solar cell materials (including organic semiconductors, colloidal quantum dots, and two-dimensional semiconductors) require energy transport in order to realize efficient solar photoconversion. In these systems, energy is transported by particles known as excitons, whose migration is characterized in terms of a diffusion length. Device-based measurements of exciton diffusion are attractive as the information extracted can be directly used to interpret device results and guide efforts in solar cell design. Previous device-based measurements have been limited by unknown losses and the need for inaccurate approximations. These issues are resolved in this new work, permitting intrinsic measurements of exciton diffusion in working solar cells. The team probed exciton transport in thin films of both organic semiconductors and colloidal quantum dots, demonstrating the breadth of this approach across materials classes. This new methodology will be of use to probe energy transport in a range of solar materials, helping to guide the design of cells with higher performance.
Related Link: https://doi.org/10.1038/s41467-019-09062-8