Paper
26 May 1994 Characterization by line-shape analysis of photoreflectance spectra for modulation-doped strained quantum wells
Godfrey Gumbs, Danghong Huang
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Abstract
The electromodulation method of contactless electroreflectance has been used to characterize strained-layer, modulation-doped Ga1-yAlyAs/InxAs/GaAs quantum wells that contain a 2DEG. Measurements were made over a wide temperature range. A first- principles many-body lineshape model has been developed. We find that manu-body effects play a role at all temperatures, but they are most pronounced at lower temperatures. The thermal broadening of the lineshape of the peaks corresponding to the interband transitions depends sensitively on the Fermi energy EF and the temperature, thereby providing us with a method to determine EF from a detailed lineshape fit. The electron density n2D is in good agreement with the sheet densities obtained from low-temperature Hall measurements. The variations in the quantum well width, alloy composition, and symmetry have been characterized by fitting the lineshapes with appropriate fitting parameters.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Godfrey Gumbs and Danghong Huang "Characterization by line-shape analysis of photoreflectance spectra for modulation-doped strained quantum wells", Proc. SPIE 2141, Spectroscopic Characterization Techniques for Semiconductor Technology V, (26 May 1994); https://doi.org/10.1117/12.176860
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KEYWORDS
Absorption

Excitons

Quantum wells

Modulation

Phonons

Interfaces

Scattering

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