| 초록 |
Solution processed bilayer organic solar cells (OSCs) with high performance are demonstrated for non-fullerene small molecular acceptors (NFAs). Unlike fullerene acceptors, NFAs show significant overlap between their absorption and the donor polymers emission, which only makes the design of efficiently exciton harvesting bilayer heterojunction possible. Efficient exciton diffusion in the organic bilayer heterojunction is realized by long-range energy transfer between a polymer donor and NFAs. We observed efficient exciton diffusions from the polymer/NFA bilayer heterojunctions via thickness-dependent photoluminescence (PL) quenching and time-resolved PL measurements. Overall, polymer/NFA bilayer OSCs demonstrated a power conversion efficiency of 9-10% which is comparable to the photovoltaic performance of bulk heterojunction OSCs, however, at the advantage of dramatically simplified microstructure formation. |
