Synthesis of arsenic-doped p-type ZnO films by addition of As2O3 to the ZnO spin coating solution

• Preparation of arsenic-doped p-type ZnO films by sol–gel spin coating synthesis.
• Improvement of crystallinity and increase in the optical bandgap energy.
• Increase in the carrier concentration and mobility with decrease in the resistivity to 3.99×10-3 Ω cm.

Arsenic-doped ZnO films were prepared by adding As2O3 to sol–gel ZnO spin coating synthesis. The preferential (002) orientation improved, and the grain size of ZnO lattice increased with As-doping in ZnO films. UV transmittance over 70% with a blue shift was observed after As-doping. In particular, ZnO film with an As concentration of 6.7 at% showed a carrier concentration of 1.62×1019/cm3, mobility of 94.0 cm2/Vs, and resistivity of 3.99×10−3 Ω cm. It was suggested that formation of As–2VZn increased the carrier concentration and induced the blue shift, and the increase in grain size increased the mobility of p-type ZnO films.