1. Delta-doped GaAs/AlAs multiple quantum wells: Study by optical and terahertz techniques
- Author
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B. Sherliker, Bronislovas Čechavičius, G. Krivaitė, J. Kavaliauskas, Edmund H. Linfield, Gintaras Valušis, Matthew P. Halsall, Paul Harrison, Dalius Seliuta, and Suraj P. Khanna
- Subjects
Photocurrent ,Materials science ,Condensed matter physics ,Terahertz radiation ,Surface photovoltage ,Exciton ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Molecular physics ,Spectral line ,Gallium arsenide ,chemistry.chemical_compound ,chemistry ,Electric field ,Quantum well - Abstract
Photoreflectance (PR) and differential surface photovoltage (DSPV) spectroscopies were employed to characterize optically Be and Si δ‐doped GaAs/AlAs multiple quantum wells. The surface electric field strength was estimated from the Franz‐Keldysh oscillations clearly visible in PR spectra. Line shape analysis of DSPV spectra allowed one to estimate interband excitonic transition energies and broadening parameters for a large number of QW‐related subbands; reasonable agreement was found between experimental and calculated transition energies. The interface quality and the main factors responsible for exciton line broadening were evaluated from spectroscopic data. These MQW structures were also studied as selective THz sensors by spectral photocurrent measurements at low temperatures.
- Published
- 2007
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