Effect of substrate temperature on the optical and magnetic properties of chemical spray deposited Fe-doped ZnO thin films

The transparent conductive oxides (TCO) are widely used in different opto-electronic device applications. In the present study, iron-doped zinc oxide (FZO) thin films have been prepared on glass substrates by using chemical spray pyrolysis technique at different substrate temperatures (300-450 degrees C) for a constant Fe-doping concentration of 2 at.%. The obtained results indicated that an increase of substrate temperature (Ts) up to 400 degrees C led to an increase in the crystallinity, optical transmittance and ferromagnetic nature of the films. However, at higher substrate temperature (450 degrees C), the crystalline quality and phase purity of FZO thin film was degraded. The transmittance haze factor was evaluated from the total and diffused transmittance measurements and observed that a decrease in the haze with substrate temperature up to 400 degrees C indicated a lower scattering of the light in the films. The bandgap energy of FZO films was decreased from 3.44 eV to 3.20 eV with increase of substrate temperature up to 400 degrees C.