scholarly journals Room-temperature excitonic absorption in quantum wires

2005 ◽  
Vol 87 (22) ◽  
pp. 223119 ◽  
Author(s):  
Yasushi Takahashi ◽  
Yuhei Hayamizu ◽  
Hirotake Itoh ◽  
Masahiro Yoshita ◽  
Hidefumi Akiyama ◽  
...  
Keyword(s):  
Room Temperature ◽  
Quantum Wires ◽  
Excitonic Absorption

Fractional-dimensional excitonic absorption theory applied toV-groove quantum wires

2004 ◽  
Vol 70 (15) ◽  
Author(s):  
K. F. Karlsson ◽  
M.-A. Dupertuis ◽  
H. Weman ◽  
E. Kapon
Keyword(s):  
Quantum Wires ◽  
Excitonic Absorption ◽  
Absorption Theory

Molecular Beam Epitaxy of Znl-x Cdx Se/ZnSe Heterostructures And Their Optical Properties

1991 ◽  
Vol 228 ◽  
Author(s):  
H. Luo ◽  
N. Samarth ◽  
J. K. Furdyna ◽  
H. Jeon ◽  
J. Ding ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Room Temperature ◽  
Molecular Beam ◽  
Stimulated Emission ◽  
Optically Pumped ◽  
Absorption Coefficients ◽  
Excitonic Absorption ◽  
Lasing Mechanism

ABSTRACTSuperlattices and quantum wells of Znl-xCdxSe/ZnSe, and heterostructures based on ZnSe/CdSe digital alloys have been grown by molecular beam epitaxy (MBE). Their optical properties were studied with particular emphasis on excitonic absorption and photopumped stimulated emission. Excitonic absorption is easily observable up to 400 K, and is characterized by extremely large absorption coefficients (α = 2×105cm−1). Optically pumped lasing action is obtained at room temperature with a typical threshold intensity of 100 kW/cm2. The lasing mechanism in these II-VI quantum wells appears to be quite different from that in the better studied III-V materials: in our case, the onset of stimulated emission occurs before the saturation of the excitonic absorption, and the stimulated emission occurs at an energy lower than that of the excitonic absorption.

Room-Temperature Observation of Excitonic Absorption in GaxIn1-xAs/InP (0.2≤x≤0.47) Quantum Wells Grown by Chemical Beam Epitaxy

1991 ◽  
Vol 30 (Part 2, No. 5B) ◽  
pp. L885-L887 ◽  
Author(s):  
Noriyuki Yokouchi ◽  
Toshikazu Uchida ◽  
Takashi Uchida ◽  
Tomoyuki Miyamoto ◽  
Fumio Koyama ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Chemical Beam Epitaxy ◽  
Excitonic Absorption ◽  
Temperature Observation

Room Temperature Excitonic Absorption in Small Cds Crystallites

1989 ◽  
Vol 164 ◽  
Author(s):  
D.K. Rai ◽  
Binod Kumar
Keyword(s):  
Crystallite Size ◽  
Room Temperature ◽  
Laser Intensity ◽  
Optical Nonlinearities ◽  
Transmitted Intensity ◽  
Crystallite Growth ◽  
Exciton Absorption ◽  
Excitonic Absorption ◽  
Absorption Features ◽  
Cds Crystallites

AbstractThe absorption characteristics of commercial CdS-containing yellow glass which shows constant transmitted intensity over a range of incident CW laser intensity have been studied at room temperature. Although the thick specimen (t>0.6 mm) shows only a broad step-like feature near λ>460 nm, a thin (t-0.09 mm) specimen shows two absorption features which can be interpreted as the first two quantum-confined exciton absorption features corresponding to a crystallite size of -45 Å. The absorption spectrum of a sample (t∼O.6 mm) heated for 15 min. at 700°C shows two new absorption features at 450 nm and 380 nm, which correspond to a much smaller crystallite size of -25 Å. This reduction in size is not inconsistent with estimates made from a well-known model for crystallite growth. Some consequences of these changes in the absorption features on the optical nonlinearities of the glass will be discussed.

Quantum-Confined Electron Transitions in CdSe Nanocrystals

2000 ◽  
Vol 642 ◽  
Author(s):  
D. S. Ginger ◽  
A. S. Dhoot ◽  
C. E. Finlayson ◽  
N. C. Greenham
Keyword(s):  
Room Temperature ◽  
Electron State ◽  
Cdse Nanocrystals ◽  
Size Dependent ◽  
Excitonic Absorption ◽  
Electron Transitions ◽  
Delocalized Electron ◽  
Excitonic Transition ◽  
Dependent Absorption ◽  
Absorption Measurements

ABSTRACTWe present quasi-steady-state photoinduced absorption measurements on thin films of colloidal CdSe nanocrystals. We observe an intense, size-dependent absorption peaking in the mid-infrared when the samples are irradiated with visible light. The absorption is accompanied by a bleach in the visible near the position of the first excitonic absorption and persists with a lifetime of milliseconds at room temperature. We characterize the lifetime of the electron state and its cross-section. We attribute this feature to the 1S-1P transition of a delocalized electron. We report a bleaching of the first excitonic transition in electrically excited nanocrystal-based diode structures, and attribute it to charging of the 1S electron state.

Room temperature emission in narrow (14 nm) quantum wires with strong lateral confinement effects

1996 ◽  
Vol 159 (1-4) ◽  
pp. 455-458 ◽  
Author(s):  
G. Bacher ◽  
M. Illing ◽  
R. Spiegel ◽  
T. Kümmell ◽  
K. Herz ◽  
...  
Keyword(s):  
Room Temperature ◽  
Quantum Wires ◽  
Confinement Effects ◽  
Lateral Confinement
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