As we know, Zn thin films deposited on glass is opaque to visible light. However by doping (or maybe alloying) with oxygen, the transparency of the Zn is improves. How this can happen?
Zinc is a metal and it is opaque whereas ZnO (obtained by oxidation of zinc) is a semiconductor material with its band gap in the UV. Since it absorbs in the UV and not in the visible region it is transparent.
The answer for Dr. Ravi is very right, also this mean the material which have more energy gap exhibit more transparent, and vice verse. with best regards
But I am confused how the oxygen can make the Zn thin films transparent? Is the oxygen vary the structural properties of the Zn that makes in transparent?