OPTICAL PROPERTIES OF CdTe/ZnTe ULTRATHIN QUANTUM WELLS GROWN BY ATOMIC LAYER EPITAXY

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1667-1670 ◽  
Author(s):  
M. GARCÍA-ROCHA ◽  
I. HERNÁNDEZ-CALDERÓN
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Diffusion Length ◽  
Substrate Surface ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Low Temperature Photoluminescence

Ultrathin quantum wells (UTQWs) of CdTe within ZnTe barriers were successfully grown by atomic layer epitaxy (ALE) on GaAs(001) substrates. ALE growth of CdTe was performed by alternate exposure of the substrate surface to individual fluxes of Cd and Te. Two different samples with 2-monolayer (ML) (substrate temperature Ts= 270° C ) and 4 ML (Ts = 290° C ) CdTe QWs were grown. Low temperature photoluminescence (PL) experiments exhibited intense and sharp peaks associated to the 2 ML QWs at 2.26 eV. In the case of the nominally 4-ML-thick QW the PL spectrum presented an intense peak around 2.13 eV and two weak features around 2.04 and 1.91 eV. The first peak is attributed to ~ 3 ML QW and the second one to ~ 4 ML QW. The dominance of the 3 ML peak is mainly attributed to Cd loss in the QW due to its substitution by Zn atoms. Due to a high diffusion length of the photogenerated carriers in the barriers, quite weak signals from the ZnTe barriers were observed in both cases. Room temperature (RT) photoreflectance (PR) spectra showed contributions from the CdTe UTQWs, the ZnTe barriers, and the GaAs substrate.

Optical Properties of Doped Cd1−xMnxTe

1986 ◽  
Vol 89 ◽  
Author(s):  
Y. Lansari ◽  
N. C. Giles ◽  
J. F. Schetzina ◽  
P. Becia ◽  
D. Kaiser
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Spectral Range ◽  
Room Temperature ◽  
Far Infrared ◽  
Optical Quality ◽  
Structural Quality ◽  
Reflectance Measurements ◽  
Low Temperature Photoluminescence

AbstractThe introduction of phosphorus and arsenic dopants into bulk Cd1−xMnx Te crystals grown by the Bridgman-Stockbarger technique has been studieA-with respect to the resulting optical properties. Samples with a Mn composition in the range 0.10 < x < 0.30, both as-grown and annealed, were investigated. A combination of room temperature transmittance and reflectance measurements over the spectral range from the ultraviolet to the far infrared has been used to gain information concerning the structural quality of the samples. Low temperature photoluminescence measurements (1.6−5 K) were used to determine optical quality and excitonic energies.

scholarly journals Magnetic, Structural, and Optical Properties of Low Temperature ZnMnO Grown by Atomic Layer Epitaxy

2005 ◽  
Vol 108 (5) ◽  
pp. 915-921 ◽  
Author(s):  
A. Wójcik ◽  
M. Kiecana ◽  
K. Kopalko ◽  
M. Godlewski ◽  
E. Guziewicz ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Structural And Optical Properties

Optical Properties of Mg-GaN, GaN/AlGaN SCH structures, and GaN on ZnO Substrates

1995 ◽  
Vol 395 ◽  
Author(s):  
H. Morkoç ◽  
W. Kim ◽  
Ö. Aktas ◽  
A. Salvador ◽  
A. Botchkarev ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Temperature ◽  
Room Temperature ◽  
Stimulated Emission ◽  
Lattice Match ◽  
Photoluminescence Emission ◽  
Stacking Order ◽  
Near Ultraviolet ◽  
Side Pumping ◽  
Low Temperature Photoluminescence

ABSTRACTGaN films and GaN/AlGaN heterostructures have been gro wn by MBE. GaN films doped with varying levels of Mg indicate effective mass acceptor at low doping concentrations, as determined from strong photoluminescence emission at about 380 nm. As the Mg concentration is increased the photoluminescence emission line red shifts considerably, indicating the formation of Mg-related or induced complexes whose lifetimes are relatively short. GaN/AlGaN separate confinement heterostructures grown on sapphire show strong near ultraviolet stimulated emission at room temperature in a side-pumping configuration. The pumping threshold for stimulated emission at room temperature was found to be ∼90 kW/cm2. Initial GaN films grown on ZnO substrates show the A exciton in low temperature photoluminescence. ZnO is being considered for nitride growth because of its stacking order and close lattice match.

scholarly journals Comparison of Optical Properties of CdTe/CdMnTe Quantum Wells Grown by Molecular Beam and Atomic Layer Epitaxy

1996 ◽  
Vol 90 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
M. Godlewski ◽  
K. Kopalko ◽  
T. Wojtowicz ◽  
G. Karczewski ◽  
J. Kossut ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy

Optical Properties for ZnSe Epilayer Obtained From Photoluminescience Measurement

2006 ◽  
Vol 321-323 ◽  
pp. 1306-1308
Author(s):  
Sang Youl Lee ◽  
Kwang Joon Hong
Keyword(s):  
Optical Properties ◽  
Binding Energy ◽  
Low Temperature ◽  
Gaas Substrate ◽  
Exciton Peak ◽  
Neutral Donor ◽  
Hot Wall Epitaxy ◽  
Neutral Acceptor ◽  
Low Temperature Photoluminescence ◽  
Zn Vacancy

The ZnSe epilayers were grown on the GaAs substrate by hot wall epitaxy. After the ZnSe epilayers treated in the vacuum-, Zn-, and Se-atmosphere, respectively. The defects of the epilayer were investigated by means of the low-temperature photoluminescence measurement. The dominant peaks at 2.7988 eV and 2.7937 eV obtained from the PL spectrum of the as-grown ZnSe epilayer were found to be consistent with the upper and the lower polariton peak of the exciton, I2 (Do, X), bounded to the neutral donor associated with the Se-vacancy. This donorimpurity binding energy was calculated to be 25.3 meV. The exciton peak, I1 d, at 2.7812 eV was confirmed to be bound to the neutral acceptor corresponded with the Zn-vacancy.

Quantum islands formation and optical properties of CdZnTe/ZnTe quantum wells grown by atomic layer epitaxy

2005 ◽  
Vol 242 (9) ◽  
pp. 1824-1828 ◽  
Author(s):  
E. M. Larramendi ◽  
O. de Melo ◽  
I. Hernández-Calderón
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy

Optical properties of Zn(S,Se) sawtooth superlattices grown by atomic layer epitaxy

1996 ◽  
Vol 80 (4) ◽  
pp. 2363-2366 ◽  
Author(s):  
Hiroyuki Fujiwara ◽  
Toshiyuki Nabeta ◽  
Isamu Shimizu ◽  
Takashi Yasuda
Keyword(s):  
Optical Properties ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy

Optical properties of quantum wells grown upon gas source molecular‐beam epitaxy low‐temperature buffers

1991 ◽  
Vol 69 (11) ◽  
pp. 7942-7944 ◽  
Author(s):  
K. T. Shiralagi ◽  
R. A. Puechner ◽  
K. Y. Choi ◽  
R. Droopad ◽  
G. N. Maracas
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Gas Source

Impurity and Stoichiometry Control in Atomic Layer Epitaxy

1992 ◽  
Vol 262 ◽  
Author(s):  
H. Yokoyama ◽  
K. Ikuta ◽  
N. Inoue
Keyword(s):  
Point Defects ◽  
Resonant Tunneling ◽  
Room Temperature ◽  
Defect Density ◽  
Atomic Layer ◽  
Negative Resistance ◽  
Atomic Layer Epitaxy ◽  
Tunneling Diode ◽  
Order Of Magnitude ◽  
Stoichiometry Control

ABSTRACTWe investigate the intrinsic point defects in epilayers grown by atomic layer epitaxy (ALE). Ga vacancies and antisite As atoms in the epilayers are detected by photoluminescence spectroscopy. This shows that the ALE epilayer was grown under As-rich conditions. We propose increasing the TMG flux to reduce the number of point defects. With this method, the number of point defects in ALE epilayers can be decreased to less than that in conventionally grown epilayers. Moreover, it is'found that these point defects are formed by the incomplete Ga coverage, not by the steric hindrance as previously suggested. The carbon concentration is decreased by one order of magnitude by using nitrogen instead of hydrogen as the carrier gas. As an application of this low defect density, we fabricated a GaAs/AlAs resonant tunneling diode and observed the negative resistance at room temperature.

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