Transparent and conductive molybdenum-doped ZnO thin films via chemical vapor deposition

Extrinsically doped ZnO is widely used as a transparent conducting electrode and has the potential to alleviate the demand on the expensive but ubiquitous Sn-doped In ₂O ₃. Here, we report for the first time the synthesis and characterization of molybdenum-doped ZnO via a chemical vapor deposition route. Films were grown by using diethylzinc, molybdenum hexacarbonyl, toluene, and methanol. All films had visible light transmittance of ∼80% and electrical resistivity of 10 ⁻³ Ω·cm with the lowest resistivity of 2.6 × 10 ⁻³ Ω·cm observed for the 0.57 at. % Mo-doped film. X-ray photoelectron spectroscopy of the surface species and X-ray diffraction based calculations of the ZnO unit cell parameters suggest that Mo is present in the 4+ oxidation state, thus contributing two electrons for electrical conduction for every Zn ²⁺ ion replaced in the lattice.