Strong adhesion and high optoelectronic performance hybrid graphene/carbon nanotubes transparent conductive films for green-light OLED devices

Carbon nanotubes (CNTs) and graphene (Gr) are promising materials for flexible transparent conductive films (TCFs) in optoelectronic application because of their exceptional electrical, optical, and mechanical properties . Here, high-quality graphene nanosheets were synthesized by the one-step green method which using natural polyphenols-gallic acid (GA) as the exfoliation medium through high-pressure homogenization ; besides, GA molecules can also be used as a non-covalent modifier to obtain GA modified CNTs (GCNTs). Then, the Au decorated Gr/GCNT-PET (Au-Gr/GCNT-PET) TCFs were obtained by a simple spray-coating process. The TCFs exhibited an excellent optoelectronic performance ( Rs  = 45.6 Ω/sq., T  = ca. 80% at 550 nm), relatively flat surface (roughness = 12.43 nm), good bending resistance (the ΔR Au-Gr/GCNT-PET TCF /R 0 was 0.07 after 1000 times bending tests) and strong adhesion (the f T of all Au-Gr/GCNT PET films was higher than 0.8). Finally, the Au-Gr/GCNT-PET films were used as an anode to prepare flexible green-light OLED devices; the maximum luminance of the Au-Gr/GCNT-PET device was 6554.1 cd/m 2 at 15V, and the maximum current efficiency was 4.03 cd/A. It confirmed that this type of TCFs has considerable potential application in photovoltaic devices .