Study on the Effect of 8 nm Size Multi Walled Carbon Nanotubes (MWCNT) on the Barrier Height of Malachite Green (MG) Dye Based Organic Device

Authors: Sudipta Sen, Nabin Baran Manik

Last Update 28 Jan 2020

Abstract :

In this paper, we have studied the effect of 8 nm sized multi walled carbon nanotubes (MWCNT) on the barrier height (ϕ_b) of ITO coated glass/Malachite Green (MG) dye /Aluminium (Al) based organic device. Presence of 8 nm MWCNT reduces the metal-organic interfacial barrier height as it enhances the charge separation and relaxation process. 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 MWCNT by using spin coating technique. We have measured the steady state current-voltage (I-V) characteristics of the device to estimate the Vth and barrier height (ϕ_b) of the device. In the presence of 8 nm MWCNT, Vth is reduced from 3.9 V to 2.37 V and ϕ_(b )is reduced from 1.12 eV to 0.97 eV. Reduction of the threshold voltage and barrier height in the presence of MWCNT indicates the enhancement of charge injection through the metal- organic dye interface. By suitable doping or addition of MWCNT within the MG dye it is possible to modify the barrier height and thereby to control the threshold voltage and the conductivity.