Exciton fission enhanced silicon solar cell
Narumi Nagaya, Kangmin Lee, Collin F. Perkinson, Aaron Li, Youri Lee, Xinjue Zhong, Su-Jin Lee, Leah P. Weisburn, Janet Z. Wang, Tomi K. Baikie, Moungi G. Bawendi, Troy Van Voorhis, William A. Tisdale, Antoine Kahn, Kwanyong Seo, Marc A. Baldo
Abstract
While silicon solar cells dominate global photovoltaic energy production, their continued improvement is hindered by the single-junction limit. One potential solution is to use molecular singlet exciton fission to generate two electrons from each absorbed high-energy photon. We demonstrate that the long-standing challenge of coupling molecular excited states to silicon solar cells can be overcome using sequential charge transfer. Combining zinc phthalocyanine, aluminum oxide, and a shallow junction crystalline silicon microwire solar cell, the peak charge generation efficiency per photon absorbed in tetracene is (138% ± 6%), comfortably surpassing the quantum efficiency limit for conventional silicon solar cells and establishing a new, scalable approach to low-cost, high-efficiency photovoltaics.