Highly transparent conductive Ga doped ZnO films in the near-infrared wavelength range

Highly transparent Ga doped ZnO thin films were prepared on (0001) sapphire substrates by pulsed laser deposition. Hall-effect measurement reveals that electron concentration of the ZnO films can be controlled between 10(18) and 10(21) cm(-3) by adjusting Ga contents in the targets. Optical measurements show the transmittance is above 60 % in the near-infrared wavelength region for all Ga doped ZnO films. Meanwhile, these films also have high crystal quality and smooth surface when the electron concentration up to 10(21) cm(-3), suggesting that the Ga doped ZnO is a promising material for using as transparent electrode for near infrared optoelectronic devices.