TERAHERTZ EMITTERS AND DETECTORS BASED ON SiGe NANOSTRUCTURES

2004 ◽  
Vol 03 (01n02) ◽  
pp. 171-176
Author(s):  
J. KOLODZEY ◽  
T. N. ADAM ◽  
R. T. TROEGER ◽  
P.-C. LV ◽  
S. K. RAY ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Silicon Germanium ◽  
Molecular Beam ◽  
Heavy Hole ◽  
State Transitions ◽  
Intersubband Transitions ◽  
Boron Doped ◽  
Different Types ◽  
Device Applications ◽  
Dopant Atoms

Terahertz (THz) electroluminescence was produced by three different types of sources: intersubband transitions in silicon germanium quantum wells, resonant state transitions in boron-doped strained silicon germanium layers, and hydrogenic transitions from dopant atoms in silicon. The devices were grown by molecular beam epitaxy, fabricated by dry etching, and characterized by infrared spectroscopy. The absorption of THz was observed in silicon germanium quantum wells at energies corresponding to heavy hole and light hole intersubband transitions. These results suggest that SiGe nanotechnology is attractive for THz device applications.

TERAHERTZ EMISSION FROM ELECTRICALLY PUMPED SILICON GERMANIUM INTERSUBBAND DEVICES

2007 ◽  
Vol 17 (01) ◽  
pp. 115-120
Author(s):  
N. Sustersic ◽  
S. Kim ◽  
P.-C. Lv ◽  
M. Coppinger ◽  
T. Troeger ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Silicon Germanium ◽  
Heavy Hole ◽  
Light Hole ◽  
Spectral Lines ◽  
Intersubband Transitions ◽  
Terahertz Emission ◽  
Drive Current ◽  
Quantum Well Width

In this paper, we report on current pumped THz emitting devices based on intersubband transitions in SiGe quantum wells. The spectral lines occurred in a range from 5 to 12 THz depending on the quantum well width, Ge concentration in the well, and device temperature. A time-averaged power of 15 nW was extracted from a 16 period SiGe/Si superlattice with quantum wells 22 Å thick, at a device temperature of 30 K and a drive current of 550 mA. A net quantum efficiency of approximately 3 × 10-4 was calculated from the power and drive current, 30 times higher than reported for comparable quantum cascades utilizing heavy-hole to heavy-hole transitions and, taking into account the number of quantum well periods, approximately four times larger than for electroluminescence reported previously from a device utilizing light-hole to heavy-hole transitions.

Photoreflectance study of hydrogenated (InGa)(AsN)/GaAs heterostructures

2002 ◽  
Vol 744 ◽  
Author(s):  
M. Geddo ◽  
G. Guizzetti ◽  
R. Pezzuto ◽  
A. Polimeni ◽  
M. Capizzi ◽  
...  
Keyword(s):  
Binding Energy ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Heavy Hole ◽  
Energy Transition ◽  
Blue Shift ◽  
Spectral Features ◽  
Single Quantum ◽  
Electron Effective Mass ◽  
Gaas Substrates

ABSTRACTWe report on photoreflectance measurements performed in the 0.8–1.6 eV photon energy range in as grown and hydrogenated InxGa1-xAs1-yNy/GaAs single quantum wells grown on GaAs substrates by molecular beam epitaxy. In the hydrogenated samples, a blue-shift of all the QW spectral features and a surprising change with temperature in the nature of the lowest energy transition are found. These features are related to the interaction of H with N atoms. An increase in the binding energy of the heavy-hole exciton upon N introduction into the InxGa1-xAs lattice has been measured also and explained in terms of an increase in the electron effective mass.

Electron Transport in InAs/AlSb Quantum Wells: Interface Sequencing Effects

1989 ◽  
Vol 145 ◽  
Author(s):  
Gary Tuttle ◽  
Herbert Kroemer ◽  
John H. English
Keyword(s):  
Electron Transport ◽  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Electron Mobility ◽  
Molecular Beam ◽  
Antisite Defect ◽  
The Other ◽  
Defect Model ◽  
Bottom Interface ◽  
Different Types

AbstractWe present data on electron transport in AlSb/InAs/AlSb quantum wells grown by molecular beam epitaxy. Because both anion and cation change across an InAs/Alsb interface, it is possible to grow such wells with two different types of interfaces, one with an InSb-like bond configuration, the other AlAs-like. Electron mobility and concentration were found to depend very strongly on the manner in which the quantum well's interfaces were grown, with high mobilities seen only if the bottom interface is InSb-like. An As-on-Al sites antisite defect model is postulated for bottom AlAs-like interfaces.

Inter-Sub-Level Spectroscopy of P-Type Modulation-Doped Ge Quantum Dots

1999 ◽  
Vol 571 ◽  
Author(s):  
J. L. Liu ◽  
W. G. Wu ◽  
G. Jin ◽  
Y. H. Luo ◽  
S. G. Thomas ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Molecular Beam ◽  
Heavy Hole ◽  
Infrared Detector ◽  
Infrared Range ◽  
Mid Infrared ◽  
Boron Doped ◽  
Ge Quantum Dots ◽  
P Type

ABSTRACTInter-sub-level transitions in p-type modulation-doped Ge quantum dots are observed. The structure is grown by molecular beam epitaxy and consists of 30 periods of Ge quantum dots separated by 6 nm boron-doped Si layers. An absorption peak in the mid-infrared range is observed at room temperature by Fourier transform infrared spectroscopy, and is attributed to the transition between the first two heavy hole states of the Ge quantum dots. This study suggests the possible use of modulation-doped Ge quantum dots for improved infrared detector application.

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