Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5369038 | Applied Surface Science | 2009 | 5 Pages |
This study examined the role of hydrogen impurities in highly oriented ZnO thin films. Hydrogen intentionally incorporated was found to play an important role as a donor in n-type conduction, improving the free carrier concentration. The increase in the conductivity of ZnO thin films was attributed to the two centers assigned to isolated hydrogen atoms in the anti-bonding sites as well as bond-centered interstitial hydrogen located between the Zn-O bonds and Zn vacancy passivated by one or two hydrogen atoms. Micro Raman spectroscopy showed two additional modes at approximately 501 and 573Â cmâ1. These two peaks were attributed to damage to the crystal lattice, which could be explained by the optical-phonon branch at the zone boundary and host lattice defects, such as vacancy clusters, respectively.