Influence of Substrate Temperature on The Optical and Electrical Properties of GZO Thin Films

Gadoped ZnO(GZO) thin films were grown on single crystal silicon(111) and quartz glass substrates by pulsed laser deposition(PLD) method at different substrate temperatures from room temperature to 750 ℃.The change of substrate temperature leads to different diffusion and desorption rates for adsorption atoms resting on substrate surface,and results in different crystalline quality for GZO thin films.The GZO thin film grown at 450 ℃ has the best crystalline quality.The carrier concentration monotonically decreases with the increase of substrate temperature,which is related to the intrinsic defects in films.The Hall mobility first increases and then decreases with the substrate temperature increasing,it results from the variation of grain boundary scattering.And the lowest resistivity ~0.02 Ω·cm is obtained in the film prepared at 450 ℃.With the increase of substrate temperature,the optical band gap becomes narrow due to the monotonic increase of carrier concentration.The average transmittance in visible region is above 85% for all the GZO samples.Our results exhibit that the optical and electrical properties of GZO thin films prepared by PLD method can be adjusted by the change of substrate temperature.