Effects of fullerene nanoparticles and fullerite nanoparticles on the charge injection mechanism of methyl red dye based organic device

Abstract

The present work studies the injection of current at the metal–organic contact of a methyl red organic device. The poor charge injection mechanism of these organic devices is due to the high energy barrier at the contact. Our main aim is energy barrier lowering to ameliorate the current flow of the device. The estimation of the energy barrier and the influence of both fullerene and fullerite nanoparticles on it have been observed. We have sandwiched the blend of the organic dye and nanoparticles by the spin coating method in between two electrodes. We have analyzed the dark current–voltage plots of the organic device to calculate the energy barrier and turn-on voltage. Lowering of the energy barrier from 0.87 eV to 0.39 eV with fullerene nanoparticles and to 0.37 eV with fullerite nanoparticles has been observed. The turn-on voltage also reduces from 2.52 V to 2.32 V in the presence of fullerene nanoparticles and to 2.00 V in the presence of fullerite nanoparticles. To check the consistency of the obtained results from I–V plots of the device, the energy barrier has been estimated by the Norde function. This function also shows a decrease in the value of the energy barrier from 0.85 eV to 0.35 eV with fullerene nanoparticles and to 0.32 eV with fullerite nanoparticles. It has been found out that the fullerite nanoparticles show better performance in terms of the charge injection process in these organic dye based devices than the fullerene nanoparticles.