Abstract
The thermal stability of ZnO/Zn(1-x)Cd(x)O/ZnO double heterostructures grown by pulsed-laser deposition was studied by annealing them for 30 min in air at temperatures from 620 to 970 degrees C. In photoluminescence spectroscopy measurements on the as-grown samples emission with energies between 3.122 and 3.044 eV were observed, corresponding approximately to Cd-contents between 2.7% and 3.6%. Due to the annealing a monotonic blue-shift of the Zn(1-x)Cd(x)O-related luminescence was found with increasing annealing temperature. The shift was small for annealing temperatures of up to 720 degrees C, thus a stability of the heterostructures up to this temperature was concluded. The underlying diffusion process was investigated to determine the diffusion coefficient for the different annealing temperatures. The temperature dependence of the diffusion coefficient shows an activation enthalpy in the range between 2.1 and 3.5 eV, depending on the growth conditions. (C) 2011 Elsevier B.V. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 13-17 |
| Number of pages | 5 |
| Journal | Journal of Crystal Growth |
| Volume | 328 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Aug 2011 |
Keywords
- Luminescence
- Defects
- Diffusion
- Physical vapor deposition processes
- Semiconducting II-VI-materials
- VAPOR-PHASE EPITAXY
- ZNO THIN-FILMS
- DEFECT STRUCTURE
- ALLOY-FILMS
- ZINC-OXIDE
- PHOTOLUMINESCENCE
- DIFFUSION
- COPPER