Thickness-dependent stress relaxation and its unreported effect on optical band gap of Al-doped ZnO thin films have been investigated. The thinnest film (∼84 nm) had a stress of -8.39× 109 Nm-2, carrier concentration of 1.73× 1019 cm-3 and optical band gap of 3.69 eV, a value significantly higher than the reported ones. With increase in thickness, magnitude of the stress decreased, and correspondingly a redshift of fundamental absorption band edge was observed. A linear dependence of optical band gap on stress in the films with a coefficient of 54.6 meV/GPa has been observed.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)