Modulation Spectroscopy of Layered Structures

1989 ◽  
Vol 160 ◽  
Author(s):  
O.J. Glembocki
Keyword(s):  
Quantum Wells ◽  
Electronic Properties ◽  
Dielectric Function ◽  
Critical Points ◽  
Carrier Density ◽  
Room Temperature ◽  
Layered Structures ◽  
Modulation Spectroscopy ◽  
Optical And Electronic Properties ◽  
Alloy Concentration

AbstractModulation spectroscopies, such as electroreflectance and photoreflectance have become popular as room temperature probes of layered structures. Because of their derivative nature, one observes sharp optical features related to critical points in the dielectric function of the material under study. This allows us to obtain information such as alloy concentration, carrier density, well widths of quantum wells and thicknesses of the constituent layers in superlattices. In this paper, we will review the application of modulation spectroscopy to the study of optical and electronic properties of layered structures.

scholarly journals Carrier-density dependence of the photoluminescence lifetimes in ZnCdSe/ZnSSe quantum wells at room temperature

1999 ◽  
Vol 74 (22) ◽  
pp. 3359-3361 ◽  
Author(s):  
C. Jordan ◽  
J. F. Donegan ◽  
J. Hegarty ◽  
B. J. Roycroft ◽  
S. Taniguchi ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Density Dependence ◽  
Carrier Density ◽  
Room Temperature

Electronic and optical properties of AlN under pressure: DFT calculations

2017 ◽  
Vol 31 (02) ◽  
pp. 1650255
Author(s):  
Sahar Javaheri ◽  
Arash Boochani ◽  
Manuchehr Babaeipour ◽  
Sirvan Naderi
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory ◽  
Zinc Blende ◽  
Rocksalt Phase ◽  
Optical And Electronic Properties ◽  
Theoretical Results

Structural, elastic, optical, and electronic properties of wurtzite (WZ), zinc-blende (ZB), and rocksalt (RS) structures of AlN are investigated using the first-principles method and within the framework of density functional theory (DFT). Lattice parameters, bulk modulus, shear modulus, Young’s modulus, and elastic constants are calculated at zero pressure and compared with other experimental and theoretical results. The wurtzite and zinc-blende structures have a transition to rocksalt phase at the pressures of 12.7 GPa and 14 GPa, respectively. The electronic properties are calculated using both GGA and EV-GGA approximations; the obtained results by EV-GGA approximation are in much better agreement with the available experimental data. The RS phase has the largest bandgap with an amount of 4.98 eV; by increasing pressure, this amount is also increased. The optical properties like dielectric function, energy loss function, refractive index, and extinction coefficient are calculated under pressure using GGA approximation. Inter-band transitions are investigated using the peaks of imaginary part of the dielectric function and these transitions mainly occur from N-2[Formula: see text] to Al-3[Formula: see text] levels. The results show that the RS structure has more different properties than the WZ and ZB structures.

scholarly journals Nanowires by Step Decoration

MRS Bulletin ◽  
1999 ◽  
Vol 24 (8) ◽  
pp. 20-24 ◽  
Author(s):  
F.J. Himpsel ◽  
T. Jung ◽  
A. Kirakosian ◽  
J.-L. Lin ◽  
D.Y. Petrovykh ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Electronic Properties ◽  
Self Assembly ◽  
Room Temperature ◽  
Electronic Materials ◽  
Layer By Layer ◽  
Optimum Thickness ◽  
Single Digit ◽  
Cooperative Phenomenon ◽  
Nanometer Regime

Recent advances in the control of thin films and surfaces have brought an intriguing question within reach: Is it possible to tailor the electronic properties of solids by controlling them layer by layer or row by row? Customized molecules are commonplace in biochemistry. Can the same idea be brought to bear on solids and electronic materials? Electronic properties of semiconductor devices have been controlled by hetero-structures, quantum wells, and super-lattices. Magnetism as a cooperative phenomenon lends itself to manipulation in small structures, where neighbor atoms can be replaced systematically by species with stronger or weaker magnetism. In fact, a class of magnetic/nonmagnetic multilayers termed spin valves has recently been introduced into commercial read heads for magnetically stored data. The optimum thickness of their active region lies in the single-digit-nanometer regime.The smallest nanostructures may be viewed as objects consisting only of interfaces with no bulk behind them. More typically, single-digit-nanometer dimensions are sufficient for realizing the benefits of structuring (e.g., operating a quantum-well device at room temperature). This regime is difficult to reach with lithography methods, particularly when macroscopic amounts are to be fabricated. Self-assembly becomes the method of choice.

scholarly journals Interband transitions inInxGa1−xAs/In0.52Al0.48As single quantum wells studied by room-temperature modulation spectroscopy

1993 ◽  
Vol 47 (12) ◽  
pp. 7198-7207 ◽  
Author(s):  
A. Dimoulas ◽  
J. Leng ◽  
K. P. Giapis ◽  
A. Georgakilas ◽  
C. Michelakis ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Temperature Modulation ◽  
Interband Transitions ◽  
Single Quantum ◽  
Modulation Spectroscopy
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