LARGE TRANSMITTANCE CHANGES INDUCED IN GA-DOPED ZNO THIN-FILMS PREPARED BY PULSED-LASER DEPOSITION

Thin films of ZnO:Ga (GZO) have been deposited on glass substrates at room temperature by a pulsed laser deposition technique using a Nd:YAG laser (lambda = 1064 nm). The 100-nm-thick GZO films grown in vacuum were dark brown and showed optical transmittance of less than 20% in t he 300-3200 nm wavelength region. On the other hand, it was found that GZO films grown in vacuum and annealed at 400-420 degrees C for 3-5 m in showed an average transmittance of above 80% in the 400-3200 nm wav elength region. GZO films with large transmittance changes in the 400- 600 nn wavelength region can be applied to high-density optical record ing films.