An explanation for anomalous donor activation energies in Al0.35Ga0.65As
- 15 July 1982
- journal article
- research article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 41 (2) , 189-191
- https://doi.org/10.1063/1.93457
Abstract
Transport properties of Si‐doped Al0.35Ga0.65 As epitaxial layers grown by molecular beam epitaxy were studied and the activation energy of the Si donors determined. Previously reported values for the Si‐donor activation energy for x = 0.35 have varied considerably and values as high as 100 meV have been suggested. For x values above and below x = 0.35, the activation energies reported are much lower, and show better consistency. Anomalously high activation energies for Se (300 meV) and Te (150 meV) doped AlxGa1−x As near the direct‐indirect transition have also been reported. In this letter, a possible explanation for these anomalies in previous results based on the modulation doping effect is described. Results obtained for layers grown so as to avoid modulation doping indicate the activation energy of Si in Al0.35Ga0.65 As is less than 14 meV. When modulation doping effects were not suppressed, apparent activation energies as high as 125 meV were obtained. Finally, electron mobilities in samples not displaying modulation doping effects for an electron concentration of 6.5×1017 cm−3 were approximately 1 100 cm2/Vs.Keywords
This publication has 17 references indexed in Scilit:
- Donor energy level for Se in Ga1−xAlxAsApplied Physics Letters, 1982
- Interfacial properties of (Al,Ga)As/GaAs structures: Effect of substrate temperature during growth by molecular beam epitaxyJournal of Applied Physics, 1982
- Short-wavelength continuous 300-K photopumped AlxGa1−xAs-GaAs quantum well heterostructure laser (λ≳7270 Å)Applied Physics Letters, 1982
- Dependence of the structural and optical properties of GaAs-Ga1−xAlxAs multiquantum-well structures on growth temperatureApplied Physics Letters, 1981
- An Anomaly in the Relation of Hall Coefficient to Resistivity in n-Type AlxGa1-xAsJapanese Journal of Applied Physics, 1981
- Transport properties of Sn-doped AlxGa1−xAs grown by molecular beam epitaxyJournal of Applied Physics, 1980
- Electron transport and band structure ofalloysPhysical Review B, 1980
- Electron mobilities in modulation-doped semiconductor heterojunction superlatticesApplied Physics Letters, 1978
- Te and Ge — doping studies in Ga1−xAlxAsJournal of Electronic Materials, 1975
- Phase equilibria in the system Al–Ga–As–Sn and electrical properties of Sn-doped liquid phase epitaxial AlxGa1−xAsJournal of Applied Physics, 1973