Temperature dependence of excitonic absorption spectra in ZnO/Zn0.88Mg0.12O multiquantum wells grown on lattice-matched substrates

• Main Authors: Sun, Handong, Makino, T., Tuan, N. T., Segawa, Y., Kawasaki, M., Ohtomo, A., Tamura, K., Koinuma, H.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2009
• Subjects: DRNTU::Science::Physics::Optics and light
• Online Access: https://hdl.handle.net/10356/101293; http://hdl.handle.net/10220/6155; http://scitation.aip.org.ezlibproxy1.ntu.edu.sg/getabs/servlet/GetabsServlet?prog=normal&id=APPLAB000078000017002464000001
• Institution: Nanyang Technological University

The excitonic properties of high-quality ZnO/Zn0.88Mg0.12O multiquantum wells grown by laser-molecular-beam epitaxy were investigated using temperature-dependent optical absorption spectra from 5 K to room temperature. The strength of exciton-longitudinal-optical (LO) –phonon coupling was deduced from the temperature dependence of the linewidth of the fundamental excitonic peak. Effective reduction of the exciton (LO) -phonon coupling with decreasing the well width was observed, which is consistent with the confinement-induced enhancement of the exciton binding energy. The thermal shift of the lowest excitonic energy is independent of well width, indicating that the strain effect is negligible for this material.