Observation of a Two-Dimensional Electron Gas in the AlGaN/GaN on SiC Substrates

1996 ◽  
Vol 449 ◽  
Author(s):  
G. C. Chi ◽  
C. F. Lin ◽  
H. C. Cheng ◽  
J. A. Huang ◽  
M. S. Feng ◽  
...  
Keyword(s):  
Electron Gas ◽  
Thick Layer ◽  
Chemical Vapor ◽  
High Electron ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Growth Pressure ◽  
Dimensional Electron Gas ◽  
Gan Film

ABSTRACTGaN/Al0.08 Ga0.92 N heterostructure has been grown on(0001) 6H-SiC substrates using low pressure metalorganic chemical vapor deposition(LP-MOCVD). Triethylgallium (TEGa), trimethylaluminum(TMA) and ammonia(NH3) were used as the Ga, Al and N sources, respectively. The carrier gas is hydrogen(H2)and the growth pressure is kept at 76 torr. Five pairs of GaN/Al0.08 Ga0.92N(100Å/100Å)were used as buffer layer, then follow by an 1.3 μ m GaN film. The 500Å AlGaN bulk structure was grown on the GaN and Finally an 100Å GaN cap layer to prevent the oxidation of AlGaN layer. The full width half maxima(FWHM) of x-ray peak is 115 arc second for the thick layer of GaN (1.3 μ m), this value is smaller than we reported for the GaN on sapphire substrate (It was about 300 arc second). The Hall mobility and sheet carrier concentration are 887 cm2/Vs, 1.0 × 1016cm-2 at 300K and 4661 cm2/Vs, 7.2 × 1012cm-2 at 77K. This high electron mobility is an indication of a two-dimensional electron gas(2DEG) formed at the GaN/AlGaN interface.

High Mobility Two-Dimensional Electron Gas in Modulation-Doped Si/SiGe Heterostructures

1991 ◽  
Vol 220 ◽  
Author(s):  
P. J. Wang ◽  
B. S. Meyerson ◽  
K. Ismail ◽  
F. F. Fang ◽  
J. Nocera
Keyword(s):  
High Vacuum ◽  
Electron Gas ◽  
Ultra High Vacuum ◽  
Threading Dislocation ◽  
High Electron ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Vapor Deposition Technique ◽  
Dimensional Electron Gas

ABSTRACTWe report record-high electron mobilities obtained in the Si/SiGe alloy system via single-junction n-type modulation-doped Si/Si0.7Ge0.9 heterostructurcs grown by the ultra-high vacuum chemical vapor deposition technique. Peak electron mobilities as high as 1,800 cm2/Vs, 9,000 cm2/Vs and 19,000 cm2/Vs were measured at room temperature, 77K and 1.4K, respectively. These high mobilities resulted from excellent Si/SiGe interfacial properties by employing a compositional graded Si/SiGe superlattice prior to the growth of a thick S0.7Ge0.3 buffer, which brought about a dramatic reduction of the threading dislocation density in the active Si channel. Two thin phosphorous-doped layers were incorporated in the SiGe barrier and at its surface to supply electrons to the Si channel and to suppress the surface depletion, respectively. The transport properties of these heterostructurcs were determined to be those of a two dimensional electron gas at Si/SiGe heterointerfaces at low temperatures.

scholarly journals Двумерные триплетные магнитоэкситоны и магнетофермионный конденсат в GaAs/AlGaAs гетероструктурах

2018 ◽  
Vol 60 (8) ◽  
pp. 1597
Author(s):  
Л.В. Кулик ◽  
А.В. Горбунов ◽  
А.С. Журавлев ◽  
В.Б. Тимофеев ◽  
И.В. Кукушкин
Keyword(s):  
Filling Factor ◽  
Electron Gas ◽  
External Electromagnetic Field ◽  
Collective State ◽  
High Electron ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Bose Statistics ◽  
Dimensional Electron Gas

AbstractA fundamentally new collective state, namely, the magnetofermionic condensate, is discovered during photoexcitation of a sufficiently dense gas of long-lived triplet cyclotron magnetoexcitons in a twodimensional Hall insulator with a high electron mobility, a filling factor of ν = 2, and temperatures of T < 1 K. The condensed phase coherently interacts with an external electromagnetic field, exhibits superradiant properties in the recombination of correlated condensate electrons with heavy holes in the valence band, and spreads nondissipatively in the layer of a two-dimensional electron gas to macroscopical large distances, transferring an integer spin. The observed effects are explained in terms of a coherent condensate in a nonequilibrium system of two-dimensional fermions with a fully quantized energy spectrum, in which a degenerate ensemble of long-lived triplet magnetoexcitons obeying the Bose statistics is present.

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