A Simple Dithieno[3,2‐b:2′,3′‐d]pyrrol‐Rhodanine Molecular Third Component Enables Over 16.7% Efficiency and Stable Organic Solar Cells

Abstract

Organic solar cells (OSCs) can achieve greatly improved power conversion efficiency (PCE) by incorporating suitable additives in active layers. Their structure design often faces the challenge of operation generality for more binary blends. Herein, a simple dithieno[3,2‐b:2′,3′‐d]pyrrole‐rhodanine molecule (DR8) featuring high compatibility with polymer donor PM6 is developed as a cost‐effective third component. By employing classic ITIC‐like ITC6‐4Cl and Y6 as model nonfullerene acceptors (NFAs) in PM6‐based binary blends, DR8 added PM6:ITC6‐4Cl blends exhibit significantly promoted energy transfer and exciton dissociation. The PM6:ITC6‐4Cl:DR8 (1:1:0.1, weight ratio) OSCs contribute an exciting PCE of 14.94% in comparison to host binary devices (13.52%), while PM6:Y6:DR8 (1:1.2:0.1) blends enable 16.73% PCE with all simultaneously improved photovoltaic parameters. To the best of the knowledge, this performance is among the best for ternary OSCs with simple small molecular third components in the literature. More importantly, DR8‐added ternary OSCs exhibit much improved device stability against thermal aging and light soaking over binary ones. This work provides new insight on the design of efficient third components for OSCs.

Diketopyrrolopyrrole-Based Chlorinated Bithiophene Polymers for Organic Solar Cells: Effect of Thiophene or Pyridine Flank

“…In addition to the morphological and charge transport characterizations, we performed CA (Figure S18 and Table S5) measurements for both donor and acceptor materials to analyze their SFE and χ parameters. − The CA and SFE values of donors and acceptors and χ values between the donors and acceptors are summarized in Tables S5 and S6, respectively. We then plotted the PCE versus the absolute difference of the total SFE (|ΔSFE d+p |), the polar component (|ΔSFE p |), and dispersion component (|ΔSFE d |), as shown in Figure a–c, respectively.…”

Using Two Compatible Donor Polymers Boosts the Efficiency of Ternary Organic Solar Cells to 17.7%

“…The close γ values of PM6 and PM7-Si indicate their good miscibility. Furthermore, the Flory− Huggins interaction parameter (χ) value of the binary blend can be obtained using the formula shown as follows: 57 ( )…”

“…The close γ values of PM6 and PM7-Si indicate their good miscibility. Furthermore, the Flory–Huggins interaction parameter (χ) value of the binary blend can be obtained using the formula shown as follows: , where γ A and γ B are the surface energy values of components A and B calculated from the contact angle measurements, respectively. The χ values for PM6:C9 and PM7-Si:C9 are 0.86. and 0.50, respectively.…”

Impact of Sequential Fluorination of Donor and/or Acceptor Polymers on the Efficiency and Morphology of All-Polymer Solar Cells

“…This is explained by the larger polarizability of small molecules than polymers, which links to the dispersion component, , whereas the polar component becomes predominant in the polymer:polymer blend. We have also calculated the Flory–Huggins interaction parameter (χ) according to the following equation reported in the previous literature with the SFE values of donor and acceptor components (γ donor and γ acceptor , respectively). − …”