Abstract
ZnO thin film has been deposited on a sapphire (001) at a temperature of 400 °C using a pulsed laser deposition (PLD) with oxygen pressures of 50, 200, 300 and 500 mTorr. As the oxygen pressure for the thin film deposition increases, the crystallinity of the samples degrades as measured by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). In contrast, the photoluminescence (PL) intensity of ultra-violet (UV) luminescence increases as the oxygen pressure increases up to 300 mTorr. This is probably because the stoichiometry of oxygen-deficient ZnO film is improved by increasing oxygen pressure. According to the results from Hall measurements, the oxygen vacancy as a native donor defect in the ZnO decreases in concentration as the pressure increases. It is concluded that the UV luminescence intensity strongly depends on the stoichiometry in the ZnO film rather than the micro-structural quality of the crystal.
| Original language | English |
|---|---|
| Pages (from-to) | 301-305 |
| Number of pages | 5 |
| Journal | Materials Science and Engineering B: Solid-State Materials for Advanced Technology |
| Volume | 71 |
| Issue number | 1-3 |
| DOIs | |
| Publication status | Published - 2000 Feb 14 |
| Event | The European Materials Research Society 1999 Spring Meeting, Symposium F: Process Induced Defects in Semiconductors - Strasbourg, France Duration: 1999 Jun 1 → 1999 Jun 4 |
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering