OSCs have mainly employed bulk heterojunction (BHJ) structures in the photoactive layers, in which the blend casting (BC) of donor (D) and acceptor (A) materials can form interpenetrating networks with a large D/A interface area for exciton dissociation. However, it is challenging to delicately balance the self-aggregation and miscibility of the two components during the one-step deposition, involving complicated dynamic and kinetic processes. [12] Accordingly, the photovoltaic performances of BC devices depend strongly on the conditions of host solvents, [13] blending ratio of D:A, [14][15][16][17][18] processing additives, [19][20][21][22] and post-treatment. [23] Thus, it is difficult to control the film morphologies, especially the D/A distribution in the vertical direction of BC films, [12] which is closely related to the charge transport and collection.To tailor vertical phase distribution efficiently, the two-step deposition of D and A materials in a sequence, namely, the sequential deposition (SD) method, is considered as an alternative to the BC process. [24][25][26][27][28][29][30][31][32][33] Since the deposition of D and A can be performed independently, the SD OSCs offer unique advantages, including a favored vertical phase distribution and improved film morphology, which provides sufficient D/A interface area, and direct transport pathways for charge carriers. [34][35][36] Obviously, it is beneficial to exciton dissociation and chargeThe variation of the vertical component distribution can significantly influence the photovoltaic performance of organic solar cells (OSCs), mainly due to its impact on exciton dissociation and charge-carrier transport and recombination. Herein, binary devices are fabricated via sequential deposition (SD) of D18 and L8-BO materials in a two-step process. Upon independently regulating the spin-coating speeds of each layer deposition, the optimal SD device shows a record power conversion efficiency (PCE) of 19.05% for binary singlejunction OSCs, much higher than that of the corresponding blend casting (BC) device (18.14%). Impressively, this strategy presents excellent universality in boosting the photovoltaic performance of SD devices, exemplified by several nonfullerene acceptor systems. The mechanism studies reveal that the SD device with preferred vertical components distribution possesses high crystallinity, efficient exciton splitting, low energy loss, and balanced charge transport, resulting in all-around enhancement of photovoltaic performances. This work provides a valuable approach for high-efficiency OSCs, shedding light on understanding the relationship between photovoltaic performance and vertical component distribution.

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Ternary strategy has been demonstrated as a promising method to further boost the performance of organic solar cells (OSCs). Herein, an efficient polymer donor S3 was synthesized and incorporated into...

A 14.57% PCE is achieved in optimized ternary OSCs with 300 nm active layers compatible with R2R large-scale printing process, indicating that thick-film ternary strategy has great potential in achieving efficient large-scale OSCs.