Improvement of Photoluminescence and Photovoltaic Properties of Poly(thienylene vinylene) by Carboxylate Substitution

Conjugated polymers have been a popular research field in the past three decades since the discovery of conducting polymers in 1977,1 owing to their novel properties and promising applications in optoelectronic devices such as polymer light-emitting diodes,2 polymer solar cells (PSCs),3-5 chemical sensors,6 and nonlinear optical devices.7 Recently, conjugated polymers with low bandgaps have drawn much attention due to their potential to be intrinsic conductive polymers and red-emitting luminescent polymers as well as for their better spectral matching with the solar spectrum for the application in PSCs.3b,4c,8 Poly(thienylene vinylene) (PTV) derivatives are well-known low-bandgap polymers.9 PTVs have already proven to be inter-esting polymers with high conductivity upon doping.10 In addi-tion, PTVs have high hole mobility (ca. 0.22 cm2 V-1 s-1)11 an