Transparent and Conductive Properties of Nanocomposite Thin Film of MWCNTs and PEDOT-PSS for Applications in OLED

It is know that Multi-walled Carbon Nano Tubes (MWCNTs) are an excellent conduction nanomaterial while Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) is a conductive and transparent polymer. In this paper, we mix MWCNTs with PEDOT-PSS to create a new type of nanocomposite thin film which has both excellent conduction and transparency of each composition materials for applications in electronics and optoelectronics. The nanocomposite is synthesized by modifying MWCNTs in an acid solution then mix with PEDOT-PSS. The field emission scanning electron microscopy (FESEM) images of the fabricated thin film with 0.3 Wt% of MWCNTs show that the diameter and length of the MWCNTs are ca.10-30 nm and 300-500 nm, respectively. Electrical and optical properties of thin film are also investigated: the sheet resistance reaches the minimum value of 36.5 Ω/sq with the transparency of ca.76% at the wave length of 600 nm. Furthermore, I-V characteristics of organic light emission diodes (OLEDs) made by the synthesized nanocomposite thin films are analyzed. The ITO/PEDOT-PSS:CNTs/PVK:MEH-PPV/Al multilayer OLED exhibits well improving performance with the work function of 0.8 V corresponding with the current of 0.4 mA while the ITO/PVK:MEH-PPV/Al simple OLED has the work function of 3 V and the current of only 0.01 mA.