Abstract
We have studied the effects of the two-dimensional electron gas (2DEG) and indium surface segregation in four pseudomorphic AlGaAs/InGaAs/GaAs high electron mobility transistor structures using room-temperature phototransmittance (PT) and photoluminescence (PL) measurements. The PT spectra from the InGaAs modulation-doped quantum well channel can be accounted for by a lineshape function which is the first-derivative of a step-like two-dimensional density of states and a Fermi level filling factor. A detailed lineshape fit makes it possible to evaluate the Fermi energy, and hence the concentration of 2DEG in addition to the energies of the intersubband transitions. The lowest-lying intersubband transition has been confirmed by a comparison of the PT and PL spectra. From the difference of intersubband transition energies, the surface segregation effects of indium atoms are demonstrated.
Original language | English |
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Pages (from-to) | 103-109 |
Number of pages | 7 |
Journal | Semiconductor Science and Technology |
Volume | 14 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1999 Dec 1 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry