Bandgap Alteration of Transparent Zinc Oxide Thin Film with Mg Dopant

We have successfully demonstrated a bandgap alteration of transparent zinc oxide (ZnO) thin film with Mg dopantby using sol-gel spin coating technique. By increasing the dopant from 0 to 30 atomic percent (at.%), a decrementvalue in the cutoff is observed, where the absorption edge shifts continuously to the shorter wavelength side, towards300 nm. This resulted in a significant bandgap increment from 3.28 to 3.57 eV. However, the transmittance of the thinfilm at 350-800 nm gradually downgraded, from 93 to 80 % which is most probably due to the grain size that becomesbigger, and it also affected the electrical properties. The decrement from 45 to 0.05 mA at +10 V was observed in theI-V characteristics, concluding the significant relationship; where higher optical bandgap materials will exhibit lowerconductivity. These findings may be useful in optoelectronics devices.