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

• Hysteresis in current–voltage characteristics of solution-processed PMMA thin films.
• Role of solvent boiling point on hysteresis behavior.
• Area of the hysteresis loop increases with range of bias and sample cell temperature.
• Short circuit current increases monotonically with increasing sample temperature.
• Pore formation in PMMA matrix depends on the solvent used for film preparation.

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.

The role of solvents on current–voltage characteristic curves of PMMA thin films measured at room temperature (303 K) under dark condition is represented in the figure: curves (1) acetone, (2) benzene and (3) toluene, respectively.Figure optionsDownload as PowerPoint slide