The influence of the substitution pattern (unsymmetrical or symmetrical), the nature of the side chain (linear or branched), and the processing of several solution processable alkoxy-substituted poly(p-phenylene vinylene)s (PPVs) on the charge-carrier mobility in organic field-effect transistors (OFETs) is investigated. We have found the highest mobilities in a class of symmetrically substituted PPVs with linear alkyl chains (e.g., R-1, R-2 = n-C11H23, R-3 = n-C18H37). We have shown that the mobility of these PPVs can be improved significantly up to values of 10(-2) cm(2) V-1 s(-1) by annealing at 110° C. In addition, these devices display an excellent stability in air and dark conditions. No change in the electrical performance is observed, even after storage for thirty days in humid air.