Journal Article conjugated polymers field-effect transistors Y-series acceptors carboxylation chlorination doping double-cable conjugated polymers fused ring hole-transporting layer insulating elastomers mechanical properties microstructure miscibility nickel oxide nonchlorinated solvents organic electronics organic light-emitting diode organic solar cell organic solar cells phase separation polymer nanowires polymer solar cells random copolymer single-component organic solar cells single-crystal transistor spiroconjugation work function