Photoluminescence studies of MBE-grown ZnO and MgZnO epitaxial layers
Journal
Physica Status Solidi (C) Current Topics in Solid State Physics
Journal Volume
6
Journal Issue
12
Pages
2668-2670
Date Issued
2009
Author(s)
Kuok?tis, E.
Karaliunas, M.
Jur?enas, S.
Miasojedovas, S.
Serevi?ius, T.
Ting, S.-Y.
Huang, J.-J.
Abstract
Photoluminescence (PL) and optical gain properties of ZnO and MgZnO epitaxial layers were investigated under different excitation conditions in a wide temperature range. The high-quality layers were grown by molecular beam epitaxy technique. CW laser radiation, nano- and pico-second light pulses were used as photoexcitation source. Spontaneous, stimulated, time-resolved and time-integrated PL of ZnO-based layers are analyzed. The PL of the layers under low excitation is caused by annihilation of free excitons in the near-band-edge region. Increase of excitation in ZnO leads to radiative recombination due to non-elastic collisions of excitons with typical P-line in the spectrum. Under extremely high levels of pumping excitons undergo the Mott transition and broad electron-hole band predominates in the PL spectrum. The latter mechanism is responsible for optical gain of ZnO. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.
Other Subjects
CW-laser; Elastic collision; Electron hole; Excitation conditions; Free excitons; High quality; Latter mechanism; Light pulse; Mott transitions; Near band edge; Optical gain properties; PL spectra; Radiative recombination; Temperature range; Time-resolved; ZnO; Building materials; Crystal growth; Excitons; Insulating materials; Molecular beam epitaxy; Molecular beams; Optical gain; Photoexcitation; Photoluminescence; Pulsed laser applications; Zinc oxide
Type
conference paper