Intrinsic and Doped Zinc Oxide Nanowires for Transparent Electrode Fabrication via Low-Temperature Solution Synthesis
Undoped and doped zinc oxide (ZnO) nanowires were synthesized by decomposing metal salts in trioctylamine at 300°C. By adding metal salts during the formation of the wires, effective incorporation of Ga and Al up to 5% was achieved, as measured by energy-dispersive x-ray spectroscopy and Auger electron spectroscopy. No secondary phase was detected by high-resolution transmission electron microscopy and x-ray diffraction. The nanowires were single-crystalline with a wurtzite lattice structure. Films made with doped wires show a complex dependence of the sheet resistance on processing conditions and dopant concentration. Thermal annealing treatment reduced the sheet resistance to values of 103 Ω/square.