Dip and spin coated nanoscale transparent PMMA thin films for field effect thin film transistors and optoelectronic devices

Polymethylmethacrylate (PMMA) is one of the promising and useful polymer material and there are numerous proposals for its application in field effect thin films transistors and opto-electronic devices. Nanoscale PMMA films are prepared by dip and spin coating techniques. The FTIR analysis indicated the absence of any impurity in the dip and spin coated films. The XRD analysis of as grown and annealed films indicated amorphous nature. The SEM analysis revealed the phenomenon of self assembly on the mesocopic scale without pits and pin holes on the surface. The optical band gap determined from Tauc's plot has been found to be 3.79 eV and 3.78 eV for as grown and annealed dip coating, 3.79 eV and 3.76 eV for as grown and annealed films prepared by spin coating. The dielectric behaviour of Al/PMMA/Al sandwich structure was carried out by using LCR meter. The observed amorphous structure, smooth surface, high transmittance and dielectric properties indicated that the prepared nanoscale transparent PMMA films could be used as opto-electronic devices and high k dielectric in organic field effect thin film transistors.