p-Type Doping of Gold Nanoparticles on Ellagic Acid Noncovalently Modified Single-Walled Carbon Nanotubes Compositing with PEDOT:PSS Bilayer Films for Organic Light-Emitting Diodes

Flexible transparent conductive films currently have been an extremely critical part of various optoelectronic devices. Herein, single-walled carbon nanotubes were non-covalently modified with ellagic acid to obtain modified carbon nanotubes (ECNTs), and p-type doping of gold nanoparticles was achieved on ECNT films utilizing the HAuCl4 solution (Au-ECNTs). Afterward, Au-ECNT/PEDOT:PSS bilayer films which possess excellent optoelectronic performance were fabricated through compositing with a highly conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) by means of spin-coating. The film displayed outstanding optoelectronic performance (Rs = 42.5 Ω/sq@T = 79.8%), a rather smooth surface (roughness = 3.81 nm), superior mechanical strength (ΔR = 0.1 after 1000 times of bending cycle tests), and satisfactory adhesion (fT = 0.87). Finally, the film was employed as an anode to construct organic light-emitting diode devices with a maximum luminance of 2567 cd/m2 and a maximum current efficiency of 5.16 cd/A obtained at a 11 V voltage, which demonstrated that this type of film owns promising application prospects in the future photovoltaic device field.