Pyrene‐Fused Perylene Diimides: New Building Blocks to Construct Non‐Fullerene Acceptors With Extremely High Open‐Circuit Voltages up to 1.26 V

Abstract

Great efforts have been devoted to seeking alternative non‐fullerene acceptors for efficient polymer solar cells (PSCs). Achieving a high open‐circuit voltage (Voc) is quite challenging but is essential for practical application. Here, pyrene‐fused perylene diimide was first used as a periphery building block to construct non‐fullerene acceptors. Due to the high‐lying lowest unoccupied molecular orbitals (LUMOs) as well as balanced transport properties, the normal devices with the acceptors exhibited ultrahigh Voc values of up to 1.26 V. In addition, the achieved power‐conversion efficiency (PCE) of 5.10% is among the highest values for non‐fullerene PSCs with a Voc > 1.20 V, indicating that the pyrene‐fused perylene diimide (PDI) unit is a useful building block for the design of non‐fullerene PSCs with high Voc values. This study could benefit the realization of both a high PCE and Voc in PSCs.

Balanced Electric Field Dependent Mobilities: A Key to Access High Fill Factors in Organic Bulk Heterojunction Solar Cells

“…High carrier mobility materials have been designed to improve hole transport, reduce recombination, and enhance the FFs . New materials can be designed with better matched energy levels to increase V oc . All in all, nearly all reports on OPV cells are based on devices optimized by their PCEs .…”

Small-Molecule Electron Acceptors for Efficient Non-fullerene Organic Solar Cells

“…A pyrene-fused PDI derivative (TPAPPDI) possessed upshifting LUMO energy level and low bandgap. The devices exhibited a PCE of 5.10% with ultra-high V oc of up to 1.21V (Zhan et al, 2017 ). Two twisted propeller configuration PDI derivatives (TPH and TPH-Se) were developed.…”

Utilizing Benzotriazole and Indacenodithiophene Units to Construct Both Polymeric Donor and Small Molecular Acceptors to Realize Organic Solar Cells With High Open-Circuit Voltages Beyond 1.2 V

“…Recently, by developing novel NFSMAs with high LUMO levels and choosing suitable p-type polymers, the resulted solar cells could realize high V OC values of beyond 1.0 V (Yang et al, 2014 ; Yu et al, 2014 ; Zhang et al, 2015 , 2016 ; Baran et al, 2016 ; Fu et al, 2016 ; Li et al, 2016a ; Liu et al, 2016 ; Ni et al, 2016 ; Chen et al, 2017 ; Ding et al, 2017 ; Xiao B. et al, 2017a ; Zhan et al, 2017 ; Zhang Y. et al, 2017 ). In fact, there is always a problematic trade-off between J SC and V OC .…”

“…In fact, there is always a problematic trade-off between J SC and V OC . Thus, very limited devices could simultaneously realize a high V OC of beyond 1.2 V and a high PCE (As shown in Figure 1 ) (Fu et al, 2016 ; Xiao B. et al, 2017a ; Zhan et al, 2017 ; Zhang Y. et al, 2017 ). For example, Xie et al reported that the OSCs containing poly(3-hexylthiophene) (P3HT) as electron donor and the oligomer F4TBT4 with four repeated fluorene and di-2-thienyl benzothiadiazole units as electron acceptor can output a high V OC above 1.2 V and a PCE of 4.12% (Fu et al, 2016 ).…”

“…Our group synthesized a novel benzotriazole based acceptor, BTA2, which showed a high V OC of 1.22 V with an acceptable PCE of 4.5% with P3HT as donor (Xiao B. et al, 2017a ). Recently, a pyrene-fused perylene diimide acceptor synthesized by Li and Sun et al can achieve a high V OC of 1.21 V with a PCE of 5.10%, with the wide-bandgap polymer PBT1-EH as the donor (Zhan et al, 2017 ). Zhang et al reported a combination of perylene monoimide (PMI)-based electron acceptor and a wide-bandgap polymer of PTZ1, which demonstrated a very high V OC of 1.3 V with a PCE of 6% (Zhang Y. et al, 2017 ).…”