For development of efficient solar cell technologies, innovation in both materials and solar cell architecture are crucial. The goal of this project is to investigate heterostructures formed by stacking the atomically thin semiconductors WSe2 and MoSe2 as efficient light-harvesting devices. Thanks to their nanometer-scale thickness, vertical carrier transport lengths in such heterostructures are greatly reduced, allowing for efficient charge collection. Furthermore, their staggered type-II band alignment favors separation of photo-excited carriers into opposite layers. This simultaneously allows for direct control of carrier dynamics and bandgap tuning by external biasing. These qualities make MoSe2-WSe2 heterostructures attractive prototypes for high-efficiency photovoltaic devices. With support from the CEI, I will systematically explore these innovative structures by varying their architecture, for example, by inserting a thin dielectric to quench carrier recombination, thus increasing carrier collection efficiency. I will examine them through photocurrent spectroscopy and evaluate their performance in the context of next-gen photovoltaic devices.
Advisor Xiaodong Xu -Physics, MSE