| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1495477 | Optical Materials | 2012 | 4 Pages |
The crystal structure and morphology of ZnO, grown on silicon substrate by two-step method, were measured by X-ray diffraction and field emission scanning electron microscopy. The results reveal that the sample is mainly composed of ZnO nanorods and preferentially oriented in the c-axis direction. The photoluminescence properties of the ZnO nanorods were investigated over the temperatures from 10 K to 297 K. There exist three emission bands in near band-edge, green–yellow–orange–red and near-infrared, respectively. Donor bound exciton (D0X) and its phonon replicas emission peaks were observed in low temperature photoluminescence (PL). The D0X and its phonon replicas peak intensity decreased with the increase of temperature and disappeared when the temperature increased up to 87 K. The decay in the D0X and its phonon replicas emission peak intensity stemmed from the thermal dissociation of D0X to free exciton. Temperature-dependent second-order diffraction of the near band-edge emissions were investigated in detail.
► D0X and its phonon replicas emission peaks were observed in low temperature PL. ► The NIR emissions correspond to the second-order diffraction of the NBE emission. ► NBE and NIR emission mechanism were investigated.
