Role of solvents on the electrical conductivity of solution-processed poly (methyl methacrylate) thin films

The role of solvents on the current–voltage characteristics of solution-processed poly(methyl methacrylate) (PMMA) thin films prepared by drop casting method, using solvents of different boiling points, has been studied under different experimental conditions. Hysteresis in current–voltage characteristics, area within the hysteresis loops, short-circuit current, open-circuit voltage and surface morphology of the PMMA films have been observed to depend on the boiling point of the solvents from which the films were prepared. Dependence of various parameters on the solvent boiling points in the present experiment is related to the amount of solvent vapour absorbed (or adsorbed) in the PMMA films. The results have been explained on the basis of molecular reorganization in PMMA and creation of different conduction paths during forward and reverse bias.