Effect of shifting of aromatic rings on charge carrier mobility and photovoltaic response of anthracene and thiophene-containing MEH-PPE-PPVs

We have investigated the charge carrier mobility and photovoltaic response of two thiophene-[P1 (MEH-PPE1-PThV2) and P2 (MEH-PThE1-PPV2)] as well as two anthracene-containing poly (phenylene-ethynylene) family of polymers [P3 (MEH-PPE1-PAnV2) and P4 (MEH-PAnE1-PPV2)], whereby the position of thiophene or anthracene has been shifted from between two double bonds (P1 and P3) to the bridge between triple bond and double bond (P2 and P4). P2 shows better photovoltaic performance than P1, whereas similar photovoltaic characteristics were found for P3 and P4. The devices using the blends of P2 as donor and PCBM as acceptor (1:3 weight ratio) exhibited a short-circuit current density of JSC=5.2 mA/cm2, an open-circuit voltage of VOC=800 mV, fill factor FF=0.44 and resulting power conversion efficiency ηAM 1.5=1.8%.