Increase in the conductivity and work function of pyrosol indium tin oxide by infrared irradiation

The effect of infrared irradiation on an indium tin oxide transparent conductor prepared by a pyrosol method was investigated. As-deposited indium tin oxide was irradiated with infrared in nitrogen gas at atmospheric pressure and temperatures ranging from 50 to 430 °C. Typically, infrared irradiation of the as-deposited indium tin oxide at 400 °C for 60 min reduced the electrical resistance by 60%, raised the work function by 0.5 eV, and enlarged the optical energy band gap by 0.05 V. The resistance was mainly decreased during the initial 10 min of irradiation. The results of field emission scanning electron microscopy and X-ray diffraction analysis showed that the infrared irradiation enhanced the crystallinity of the indium tin oxide. These results, derived from treatment at atmospheric pressure and using inexpensive equipment, suggest that infrared irradiation should be an inexpensive method to reduce the resistance and raise the work function of as-deposited pyrosol indium tin oxide.