Ternary All-Polymer Solar Cells With 8.5% Power Conversion Efficiency and Excellent Thermal Stability

Abstract

All-polymer solar cells (all-PSCs) composed of polymer donors and acceptors have attracted widespread attention in recent years. However, the broad and efficient photon utilization of polymer:polymer blend films remains challenging. In our previous work, we developed NOE10, a linear oligoethylene oxide (OE) side-chain modified naphthalene diimide (NDI)-based polymer acceptor which exhibited a power conversion efficiency (PCE) of 8.1% when blended with a wide-bandgap polymer donor PBDT-TAZ. Herein, we report a ternary all-PSC strategy of incorporating a state-of-the-art narrow bandgap polymer (PTB7-Th) into the PBDT-TAZ:NOE10 binary system, which enables 8.5% PCEs within a broad ternary polymer ratio. We further demonstrate that, compared to the binary system, the improved photovoltaic performance of ternary all-PSCs benefits from the combined effect of enhanced photon absorption, more efficient charge generation, and balanced charge transport. Meanwhile, similar to the binary system, the ternary all-PSC also shows excellent thermal stability, maintaining 98% initial PCE after aging for 300 h at 65 • C. This work demonstrates that the introduction of a narrow-bandgap polymer as a third photoactive component into ternary all-PSCs is an effective strategy to realize highly efficient and stable all-PSCs.

N‐Type Quinoidal Polymers Based on Dipyrrolopyrazinedione for Application in All‐Polymer Solar Cells

“…Encouragingly, the maximum PCE up to 11.76 % was achieved by N2200‐based all‐PSCs, which was fully comparable to the highest PCE of fullerene‐based PSCs for the first time [5] . However, NDI‐based polymers including N2200 exhibited low light absorption coefficients in the near‐infrared (NIR) region, which significantly limited the short‐circuit current density ( J sc ) and further PCE enhancement of the resulting all‐PSCs [4a,d,6a,b,c,d] . Therefore, a few D‐A type conjugated polymers based on new building blocks with strong electron affinity such as bithiophene imide, [7a,b,c] double B←N bridged bipyridine, [8a,b] and 5,6‐dicyano‐2,1,3‐benzothiadiazole (DCNBT) [9a,b] were developed for use as polymer acceptors in all‐PSCs.…”

Effect of Third Component on Efficiency and Stability in Ternary Organic Solar Cells: More than a Simple Superposition

“…In general, the active layers of ternary OSCs consist of two host components (electron donor/acceptor pairs [D/A]) and a third guest component, where the third component can be materials such as polymers, [29][30][31] small molecules, [32,33] dyes, [34] or nanoparticles. [35,36] Depending on the function of the third component, ternary OSCs can be classified into three categories: 1) two D/one A (D 1 /D 2 /A), 2) one D/two A (D/A 2 /A 1 ), and 3) D/nonvolatile additive/A (D/NVA/A).…”

Current Status of Emerging PV Technologies: A Comparative Study of Dye-Sensitized, Organic, and Perovskite Solar Cells

“…A number of research efforts focus on increasing the stability of ternary OPVs through the careful selection and optimization of appropriate materials in ternary devices. Recently, Liu et al reported an 8.5% efficiency for a ternary device based on naphthalene di-imide polymer acceptor, in a blend with the polymer donors PBDT-TAZ and PTB7-Th [130]. This device exhibited high thermal stability, retaining 98% of its efficiency, after 300 h of heating at 65°.…”