Room-temperature luminescence of excitons in ZnO/(Mg,Zn)O multiple-quantum wells on lattice-matched substrates
We report on the optical properties of ZnO/(Mg, Zn)O multiple quantum wells (MQWs) on lattice-matched ScAlMgO4 substrates fabricated by laser molecular-beam epitaxy. As the well layer thickness decreased down to 7 Å, the photoluminescence (PL) and absorption peaks showed a systematic blueshift, cons...
| Main Authors: | , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2009
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/101295 http://hdl.handle.net/10220/6145 http://scitation.aip.org.ezlibproxy1.ntu.edu.sg/getabs/servlet/GetabsServlet?prog=normal&id=APPLAB000077000007000975000001 |
| Summary: | We report on the optical properties of ZnO/(Mg, Zn)O multiple quantum wells (MQWs) on lattice-matched ScAlMgO4 substrates fabricated by laser molecular-beam epitaxy. As the well layer thickness decreased down to 7 Å, the photoluminescence (PL) and absorption peaks showed a systematic blueshift, consistent with the quantum-size effect. Moreover, a bright PL of free excitons could be observed even at room temperature. As a result, the PL could be tuned in the energy range of 3.3–3.6 eV by choosing the appropriate barrier height and well layer thickness. The widest tunability on the room-temperature luminescence of the excitons could be attained on the basis of the ZnO quantum structure. These favorable properties could not be attained in the MQWs on lattice-mismatched sapphire substrates. |
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