| 초록 |
In this work, we investigated the origin of high performance in PM6:Y6 OSCs by performing a comprehensive analysis based on transient optoelectronic measurements. Compared with other non-fullerene photovoltaic blends, PM6:Y6 shows lower energetic disorder, in which low density of intra-bandgap tail states presents energetically narrow distribution. As a result, charge trapping into these trap states concomitant with losses in quasi-Fermi level splitting is largely suppressed, enabling near-ideal recombination kinetics under operational conditions. Through the density function theory (DFT) calculation, we propose the low energetic disorder in the PM6:Y6 system could be ascribed to the rigid molecular conformation of the Y6 acceptor. These findings provide useful insight into the mechanism regarding charge dynamics and address the importance of molecule design for achieving high performance in OSCs. Organic semiconductors can also be utilized in perovskite/bulk heterojunction (BHJ) integrated solar cells. The recombination kinetics correlated with the interfacial energy of the perovskite/BHJ are also briefly discussed. |
