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 °C) for a constant Fe-doping concentration of 2 at.%. The obtained results indicated that an increase of substrate temperature (T_s) up to 400 °C led to an increase in the crystallinity, optical transmittance and ferromagnetic nature of the films. However, at higher substrate temperature (450 °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 °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 °C.