Effect of laser irradiation on the properties of indium tin oxide films deposited by pulsed laser deposition

High quality indium tin oxide (ITO) films of thickness 80±20 nm grown by laser irradiation of the glass substrates during pulsed laser deposition are reported. Films were deposited from a 5 wt.% SnO2-doped In2O3 target at substrate temperatures (Ts) ranging from room temperature (RT) to 400°C and oxygen pressure (PO2) of 1.3 Pa. The energy of the laser beam focused unto the middle of the glass substrate during coatings was about 70 mJ cm−2. The structural, electrical and optical properties of the laser-irradiated and the nonirradiated parts of the ITO films were studied as a function of Ts. Crystalline films with 〈1 1 1〉 preferred orientation and crystal sizes⪢200 nm were obtained at all Ts. At RT, the resistivity of the laser-irradiated part of one film was 1.2×10−4 Ω cm compared with 2.3×10−4 Ω cm for a nonirradiated part. At 300°C, a low resistivity value of 8.5×10−5 Ω cm was achieved for both the laser-irradiated and the nonirradiated parts of the ITO film. The achievement of low resistivity resulted from the high carrier concentration ∼1.2×1021 cm−3 and the high Hall mobility (40–57) cm2 V−1 s−1. The films also exhibited high optical transmittance (∼90%) to visible light.