Patterned graphene as an anode for organic light-emitting diode

Graphene, a two-dimensional sheet of sp²-hybridized carbon atoms, has many fascinating properties, such as excellent optical transmittance, high carrier mobility and favourable flexibility. In this way, graphene was extensively researched in the past several decades, especially the cooperation with the field of optoelectronics and electronics. However, there are still many challenges which hinder the further applications of graphene, one of the most important sections is the pattern of graphene. In this work, high quality single layer graphene was grown by chemical vapor deposition (CVD), Fig. 1 shows the representative Raman spectra for graphene transferred from Cu foils to Si/SiO2 substrate, characteristic G (∼ 1585 cm⁻¹), 2D (∼ 2689 cm⁻¹) peaks and I2D/IG ∼ 2 confirming that a single layer graphene was grown, disappeared D (∼ 1350 cm⁻¹) peak means a high quality graphene with bare defects. For the further application of graphene as an anode used in OLEDs, we employ patterned vacuum thermal evaporated Cu on graphene as a protect layer, combine with the O2 plasma treatment and Cu etching process to obtain a patterned graphene anode, the detail procedures describe in Fig. 2. By engaging the patterned graphene in OLEDs, a ∼ 15 cd/A for current efficiency and over 10000 cd/m² for luminance has been obtained.