Exciton diffusion dynamics in quantum nanostructures on V-groove patterned substrates

✍ Scribed by N. Usami; Y. Shiraki; W. Pan; H. Yaguchi; K. Onabe

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 94 KB
• Volume: 23
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1996.0285

✦ Synopsis

Time-resolved photoluminescence (PL) measurements were performed for two different quantum nanostructures on V-groove patterned substrates; SiGe/Si quantum wells (QWs) on V-grooved Si substrates and AlGaAs spontaneous vertical quantum wells on V-grooved GaAs substrates. Anomalous behaviours of the PL, such as the decrease of the decay time of the SiGe (111) QWs and the (111)A AlGaAs layer, were fully explained by taking the exciton diffusion towards the bottom of the V-groove into account, showing that the exciton diffusion driven by the spatial nonuniformity of the alloy compositions and/or geometry of the substrates is a key to controlling the PL properties of the nanostructures.