Solid Additive Enables Organic Solar Cells with Efficiency up to 18.6%

Abstract

Additive strategies play a critical role in improving the performance of organic solar cells (OSCs). There are only a few reports on the application of solid additives for OSCs, which leaves a large space for further improvement of solid additives and further study on the relationship between material structure and property. PM6:BTP-eC9-based organic solar cells (OSCs) were prepared by using a small molecule BTA3 as a solid additive, and a high energy conversion efficiency of 18.65% is achieved. BTA3 has good compatibility with the acceptor component (BTP-eC9) and optimizes the morphology of the thin films. Moreover, the introduction of a small amount of BTA3 (5 wt %) effectively promotes exciton dissociation and charge transfer and suppresses charge recombination, and the relationship between the BTA3 content and the device parameter is deeply revealed. The use of BTA3 in the active layers is an attractive and effective strategy for high-performance OSCs.

Subtle structural modification of thiophene-fused benzotriazole unit to simultaneously improve the JSC and VOC of OSCs

“…S4 (ESI†) shows the Nyquist plots along with the inserted equivalent electric circuit. 46 In the inset model, R 1 and R 2 represent the transport and recombination resistance, respectively. The R 1 and R 2 of the PffBTAZT-fBDT :Y6 device are 1.71 and 829.84 Ω cm 2 , respectively, while R 1 and R 2 of the PfBTAZT-fBDT :Y6 devices are 2.28 and 488.38 Ω cm 2 , respectively.…”

18.73% efficiency organic solar cells with a medium bandgap acceptor as a third component

“…The energy transfer from excitons on IT-M to BTP-eC9 is facilitated through the Förster resonance process, resulting in increased exciton dissociation. 31 The energy transfer between the two acceptors introduces a novel method for improving the efficiency of exciton utilization in ternary OSCs. 32…”

Additive-assisted strategy for high-efficiency organic solar cells

“…Polymer donors and small molecular acceptors with appropriate miscibility, complementary absorption and compatible energy levels were also used as nonvolatile solid additives. 97–103 Cheng et al enhanced the PCE of PM6:Y6 based OSCs by utilizing two polymers PBM and PFBM as additives (Fig. 1c).…”

“…1c) as an additive into PM6:BTP-eC9 based BHJ OSCs and achieved a higher PCE of 18.65%. 98 The stair-stepping energy levels of PM6, BTP-eC9, and BTA3 can facilitate charge transfer and reduce energy loss (Fig. 8b).…”