Preparation of low resistivity transparent conductive Nb-doped TiO ₂ films by the co-sputtering method

Low resistivity Nb-doped TiO ₂ transparent conducting oxide (TNO) thin films have been achieved by a pulsed dc magnetron co-sputtering at room temperature and the annealing treatment. Pulsed dc power provides the stabilization of reactive sputtering. The dc power of Nb target is controlled to find the optimum Nb content in TNO films. The carrier concentration is linearly proportional to Nb content in TNO films. The lowest resistivity was measured as 4.55 × 10 ^-4 Ωcm at 24W dc power of Nb and the average absorbance in the visible light region was smaller than 8% for different dc powers. The results of contact angle revealed that TNO films still keep the surface hydrophilicity and have the characteristic of photocatalyst.