Synthesis of Gallium-Doped Zinc Oxide (GZO) Nanoparticles for GZO/Silver Nanowire Nanocomposite Transparent Conductive Electrodes

Gallium (Ga)-doped zinc oxide nanoparticles (GZO-NPs) have been synthesized using a heating-up method. The Ga doping concentration strongly affected the particle size, distribution, and bandgap energy of the GZO-NPs. When the Ga concentration was increased from 0% to 5%, the average size of the GZO-NPs decreased from 57 nm to 16 nm while the bandgap increased from 3.14 eV to 3.26 eV. On further increase of the Ga content to 7% and 9%, the particle size increased while the bandgap narrowed. The GZO-NPs synthesized with 5% Ga showed the best uniformity and smallest average diameter of approximately 16 nm. The GZO-NPs with 5% Ga were applied to reduce the mechanical contact between the AgNWs in GZO/silver nanowire (AgNW) composite for application as a transparent conductive electrode, yielding RSH = 18.1 Ω/□, T = 77.8% at 550 nm, and σDC/σOp = 77.53. These results indicate that such GZO-NPs are a very promising nanocrystalline ink precursor for printing thin films for application in nanocomposite transparent conductive electrodes.