Enhanced Charge Separation and Short-Circuit Current by Doping with Chlorophyll in Cascaded Ternary Solar Cells

Ternary architecture incorporating the third component is a facile and effective method to enhance the device’s performance and create excellent application prospects. However, the synergistic gain performances of multiple donors or acceptors still lack research, so exploring the mechanism of ternary organic solar cells (T-OSCs) at the microlevel is urgent. Here, a T-OSC device with the chlorophyll dye Chl-47 as the third component is constructed, pointing out that the doped Chl-47 could effectively compensate for the shortcomings of the binary device of J61/PADIOD-T, such as light absorption, energy level, and mobility. Besides, simulations at different scales show that introducing Chl-47 will affect the interfacial configuration and further adjust the charge transfer pathway. It was found that the blend of J61/Chl-47/PADIOD-T exhibits the cascade model and multistep hopping mechanism, favoring interfacial charge separation. Furthermore, global modeling is used to evaluate the relevant parameters associated with experimental characterization. Although J61/Chl-47/PADIOD-T has smaller V_oc and FF, larger J_sc leads to significant photoelectric conversion efficiency, indicating that the multistep hopping mechanism is essential for improving J_sc. Therefore, this study reveals the micro mechanism and provides ideas for further screening efficient T-OSCs.