Performance Improvement of Carbon-Nanotube-Incorporated Transparent Conducting Anode Film for Organic Device Application

Carbon nanotubes (CNTs) were incorporated into indium tin oxide and polythiophene by mixing and then spin coating or screen printing to form the transparent conducting electrode (TCE). With only approximately 0.005%, by weight, of CNTs in the TCE, the sheet resistance was found to drop by about 25% to 40%, without any significant decrease in the transmittance. Organic light-emitting devices (OLEDs) were then fabricated using these composite TCEs as the anode. In comparison with a device without the CNTs, there was an increase in the current density for the same applied voltage, mainly due to the contribution of hole current. In addition, the mechanical strength was improved, as seen from bending test of the device.