Effect of different migration energy for reaction atoms on growth orientation and optical absorption characteristics of cubic MgZnO thin films under different pressure by PLD method

摘要

Mg_(1-x)Zn_xO thin films were deposited under different pressures during the growth process, which is modulated by different Ar/O_2 flow ratio. When growth pressure increases, the growth orientation of MgZnO thin film changed from (200) to (111) because of the decrease in migration energy of reactive Mg, Zn and O atoms from MgZnO target material. The band gap of MgZnO thin films decreased when growth pressure increased from 2 Pa to 6 Pa, which is reason from more Zn atoms combined with O atoms in (111) orientation MgZnO crystal lattice in MgZnO thin film deposited at higher pressures. But when the growth pressure increased from 6 Pa to 7 Pa, the band gap value of MgZnO thin films increased because less Zn atoms than Mg atoms combined with O atoms in MgZnO crystal lattice at higher pressures with the same (111) orientation.