Baseplate Temperature‐Dependent Vertical Composition Gradient in Pseudo‐Bilayer Films for Printing Non‐Fullerene Organic Solar Cells

Abstract

Numerous previous reports on the sequential deposition (SD) technique have demonstrated that this approach can achieve a p‐i‐n active layer architecture with an ideal vertical composition gradient, which is one of the critical factors that can influence the physical processes that determine the photovoltaic performance of organic solar cells. Herein, a commonly used photovoltaic system comprised of PM6 as a donor and Y6 as an acceptor is investigated with respect to sequential blade‐processing deposition to comprehensively explore the morphology characteristics as a function of baseplate temperature. A systematic study of the temperature‐dependent blend morphology elucidates the SD‐processed configuration merits and device physics behind temperature‐controlled degree of vertical composition gradient, and constructs the temperature‐microstructure‐property relationship for the corresponding photovoltaic parameters. The result shows, as the temperature increases, the morphology of the active layer has undergone a distinct evolution from the pseudo‐bulk heterojunction to a pseudo‐planar heterojunction and then to a pseudo‐planar bilayer, leading to a non‐monotonic correlation between baseplate temperature and device performance. This investigation not only reveals the importance of precisely controlling baseplate temperature for gaining vertical morphology control, but also provides a path toward rational optimization of device performance in the lab‐to‐fab transition.

Achieving 15.81% and 15.29% efficiency of all-polymer solar cells based on layer-by-layer and bulk heterojunction structures

“…Very recently, the layer-by-layer (LbL) processing method has attracted extensive attention, in which the donor and acceptor layers are sequentially cast, which is conducive to maintaining the high purity of the donor/acceptor domain for efficient charge transport in LbL active layers. [9][10][11] The key photovoltaic parameters of the typical studies of BHJ and LbL all-PSCs are listed in Table 1. The LbL all-PSCs exhibit a relatively large PCE in comparison with the corresponding BHJ all-PSCs prepared with the same donor and acceptor materials, suggesting that the LbL processing method may have great potential in achieving highly efficient all-PSCs.…”

Optimizing sequence structures by stepwise-feeding terpolymerization for high-performance organic solar cells

“…4d), indicating negligible bimolecular recombination and more efficient charge carrier transportation in the H9:Y6-based cell. Besides, we also explore the relationship between V oc and P light via V oc f nkT/q ln P light , 26,27 and the slopes of the tting lines for the OSCs based on D18:Y6, H6:Y6, H7:Y6, H8:Y6, H9:Y6 and H10:Y6 are 1.38, 1.32, 1.43, 1.30, 1.20 and 1.45kT/q, respectively (Fig. S14 †).…”

Reducing Photovoltaic Property Loss of Organic Solar Cells in Blade‐Coating by Optimizing Micro‐Nanomorphology via Nonhalogenated Solvent

“…[18,19] As a high throughput printing technology, blade-coating is received widespread attention. [20][21][22][23] The blade-coating process has longer solvent evaporation time compared to the spin-coating process, resulting in slow film formation process. During the printing process, a large number of microcrystalline particles produced by the slow film formation provide nucleation sites for donor and acceptor, thereby increasing the crystallization of the molecules.…”