For ZnO nano photocatalyst, its bulk defects possibly act as e-h recombination centers, which will decrease the photocatalytic efficiency. Thus it is important to determine the bulk defect concentration in ZnO quantitatively or qualitatively.
Positron Annihilation Technique，PAT， I think that's one way to measure the density of point defects inside bulk materials.
Ming Xu.... the problem of defects, in particular, acceptor dopants, remains a key challenge.
In this review, defects in ZnO are discussed, with an emphasis on
the physical properties of point defects in bulk crystals. As grown, ZnO is usually n-type, a property that was historically ascribed to native defects.
Electron paramagnetic resonance EPR measurements
on electron-irradiated ZnO show neutral O vacancies and the bulk defect concentration in ZnO.
the native electrical active defects in ZnO by temperature dependent Hall measurement, deep level transient spectroscopy , photoluminescence and positron annihilation spectroscopy. TDH and DLTS measurements are used to identify and characterize the electrical active defects, while PL is a technique to reveal optical active defects.
- Badges
- Science topic