A CuO Nanowire‐Based Alternating Current Oxide Powder Electroluminescent Device with High Stability

An AC-driven powder electroluminescent (EL) device has been achieved by constructing a CuO nanowire-Zn₂ GeO₄ :Mn phosphor heterogeneous junction. The CuO nanowires enhance the local electric field, resulting in electroluminescence of an oxide-based phosphor in EL devices owing to field injection at the nanowire tips. The CuO nanowire array was synthesized by an in situ thermal oxidation method at 400 °C in air and employed as an electric field enhancement layer in the EL device. The heterogeneous structures were created through drop coating of a phosphor suspension on the CuO nanowire array. The initial EL device tests show good luminescent performance with very promising brightness maintenance for over 360 h, with a loss of luminescent intensity of under 1 % at over 10 cd m^-2 luminance. The fabrication method offers the prospect of simple, low-cost, large-scale EL devices with the potential to solve the limited operational lifetime of sulfide-based AC powder EL devices.