Effect of Fullerene Nanoparticles on Barrier Height of Crystal Violet Dye Based Organic Device

Abstract

In this work, we have estimated the barrier height (Φ b ) of ITO coated glass/Crystal Violet (CV) dye/Aluminium (AI) based organic device and subsequently we have also observed the effect of fullerene (C 60 ) nanoparticles on Φ b . Presence of C 60 nanoparticles reduce barrier height and provides easy path for charge percolation. We have used ITO coated glass as front electrode and aluminium as back electrode to form the organic device. This organic device has been prepared with and without C 60 nanoparticles by using spin coating technique. We have measured the steady state current-voltage (I- V) characteristics of the device to estimate barrier height (Φ b ) of the device. Φ b is reduced from 0.87 eV to 0.75 eV in the presence of C 60 nanoparticles. The barrier height is also estimated by using another alternative method which is known as Norde method. By using Norde method, Φ b is estimated which reduces from 0.83 eV to 0.79 eV in presence of C 60 nanoparticles. Both the methods show good consistency with each other. Reduction of the interfacial barrier height in presence of fullerene indicates the enhancement of charge injection through the metal - organic dye interface. By suitable addition of C 60 nanoparticles within the CV dye it is possible to modify the barrier height and enhance the current injection through metal-organic dye interface which also allows the device to be turned on at much lower voltages.