Photoluminescence properties: Catalyst-free ZnO nanorods and layers versus bulk ZnO

Abstract

In this contribution, we compare the photoluminescence properties of ZnO nanorods and epilayers with those of bulk ZnO. Owing to the high aspect ratio (length of 4–14μm, diameter of 80–500nm), the characterized ZnO nanorods show very good optical properties. Due to the high surface-to-volume ratio in ZnO nanorods, surface excitons dominate at low temperature. The optical properties of nanorod ensembles improve with increasing nanorod length. The photoluminescence emission from free A excitons was intense in the ZnO layer at 13K.

The Effect of Tensile Strain on Optical Anisotropy and Exciton of <inline-formula> <tex-math notation="TeX">$m$</tex-math></inline-formula>-Plane ZnO

“…The binding energy of DX 1 and DX 2 are found to be 7.0 meV and 9.0 meV, which are both close to the reported activation energy of neutral donor-bound exciton [21]- [23].…”

Zinc related defects in ZnO nanorods

“…It should be mentioned that peaks in the PL spectra of nanorods with energies close to 3.359 eV have been attributed to biexcitons [18,19]. However, the creation of biexcitons requires very high power density of the exciting radiation [20] which was not the case during our measurements.…”

Synthesis and photoluminescence of Sb-induced ZnO nanowires along with islands attached

“…The spectra are shifted in the vertical direction for clarity. dominated emissions at 3.354 eV, 3.324 eV, and 3.259 eV, which are identified as neutral-donor-bound exciton (D 0 X) [19][20][21], neutral-acceptor-bound exciton (A 0 X) [22], and donor-acceptor pair (DAP) [23,24] transitions, respectively. With an increase of the temperature, the DAP emission at 3.259 eV decreases and disappears at temperature above 50 K [23,24].…”