Optically pumped stimulated emission in ZnO/ZnMgO multiple quantum wells prepared by combinatorial techniques

doi:10.1117/12.424747

	Optically pumped stimulated emission in ZnO/ZnMgO multiple quantum wells prepared by combinatorial techniques
	Sun H.D.2; Makino T.2; Tuan N.T.2; Segawa Y.2; Tang Z.K.3; Wong G.K.L.3; Kawasaki M.1; Ohtomo A.1; Tamura K.1; Koinuma H.1
	2001
Source Publication	Proceedings of SPIE - The International Society for Optical Engineering
ISSN	0277786X
Volume	4281 Pages:68-76
Abstract	High quality ZnO/ZnMgO multi-quantum wells (MQWs) have been prepared on lattice-matched ScAlMgO substrates by laser-MBE method. Nine pixels of MQWs having different well widths were integrated in the same substrate by means of combinatorial masking techniques, which provided excellent specimens to systematically study the dependence of physical properties of MQWs on well widths. Optically pumped stimulated emission spectra were measured in these ZnO/ZnMgO multi-quantum wells by using a tunable pulsed dye laser as excitation source. We investigated the pump-intensity dependence of the stimulated emission spectra from 5 to 300 K. At low temperatures, only one peak in the stimulated emission was observed, which could be assigned to the emission induced by exciton-exciton inelastic scattering (P-band). When the temperature increases above 160 K, there appears an additional peak at the lower energy side of the P-band, which was assigned to electron-hole plasma emission. However, the emission due to the exciton-exciton scattering still remains up to room temperature. The gain spectrum for a multi-quantum well sample has been obtained by variable stripe method at room temperature. At an excitation intensity of about 2 MW/cm, the peak gains for the P-band and electron-hole plasma emission are 239 cm and 380 cm, respectively. The exciton binding energy was deduced from the energy difference between the P-band and free exciton band. The exciton binding energies of these samples having different well widths were found to increase with decreasing the well widths due to the quantum confinement effect. This enhancement of exciton binding energy should be favorable for the stability of exciton states at higher temperatures.
Keyword	Electron-hole plasma Exciton binding energy Exciton-exciton scattering Excitons Gain Laser-MBE Quantum size effect Quantum wells Stimulated emission ZnO
DOI	10.1117/12.424747
URL	View the original
Language	英語
全文获取链接	View Full-Text via DOI View Full-Text via Web of Science View Full-Text via Scopus
引用统计	被引频次[WOS]：1 [WOS记录] [WOS相关记录]
Document Type	Journal article
专题	University of Macau
Affiliation	1.Tokyo Institute of Technology 2.Riken 3.Hong Kong University of Science and Technology
推荐引用方式 GB/T 7714	Sun H.D.,Makino T.,Tuan N.T.,et al. Optically pumped stimulated emission in ZnO/ZnMgO multiple quantum wells prepared by combinatorial techniques[J]. Proceedings of SPIE - The International Society for Optical Engineering,2001,4281:68-76.
APA	Sun H.D..,Makino T..,Tuan N.T..,Segawa Y..,Tang Z.K..,...&Koinuma H..(2001).Optically pumped stimulated emission in ZnO/ZnMgO multiple quantum wells prepared by combinatorial techniques.Proceedings of SPIE - The International Society for Optical Engineering,4281,68-76.
MLA	Sun H.D.,et al."Optically pumped stimulated emission in ZnO/ZnMgO multiple quantum wells prepared by combinatorial techniques".Proceedings of SPIE - The International Society for Optical Engineering 4281(2001):68-76.