title: Modulation spectroscopy study of the effects of growth interruptions on the interfaces of GaAsSb/GaAs multiple quantum wells.
abstract: The effects of growth interruption times combined with Sb exposure of GaAsSb/GaAs multiple quantum wells (MQWs) have been investigated by using phototransmittance (PT), contactless electroreflectance (CER) and wavelength modulated surface photovoltage spectroscopy (WMSPS). The features originated from different portions of the samples, including interband transitions of MQWs, interfaces and GaAs, are observed and identified through a detailed comparison of the obtained spectra and theoretical calculation. A red-shift of the interband transitions and a broader lineshape of the fundamental transition are observed from samples grown under Sb exposure compared to the reference sample grown without interruption. The results can be interpreted in terms of both increases in Sb content and mixing of Sb in the GaAs interface layers. An additional feature has been observed below the GaAs region in the samples with Sb treatment. The probable origin of this additional feature is discussed.
authors.affiliation: Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors.forename: H P
authors.initials: HP
authors.lastname: Hsu
authors.forename: P
authors.initials: P
authors.lastname: Sitarek
authors.forename: Y S
authors.initials: YS
authors.lastname: Huang
authors.forename: P W
authors.initials: PW
authors.lastname: Liu
authors.forename: J M
authors.initials: JM
authors.lastname: Lin
authors.forename: H H
authors.initials: HH
authors.lastname: Lin
authors.forename: K K
authors.initials: KK
authors.lastname: Tiong