Room Temperature Optical Studies of GaAs/AlGaAs Coupled Double Quantum Wells

1987 ◽  
Vol 102 ◽  
Author(s):  
C. Jagannath ◽  
B. Elman ◽  
Emil S. Koteles ◽  
Y. J. Chen ◽  
S. Brown ◽  
...  

ABSTRACTRoom temperature photoreflectance (PR) spectroscopy has been utilized to study the effect of electric fields on the optical properties of GaAs/AlGaAs coupled double quantum wells (CDQWs). The behavior of optical transitions when subjected to electric fields ranging from 0 to 2×105V/cm, was found to be similar to that observed at low temperatures using photoluminescence excitation spectroscopy. Large shifts in the energies of spatially indirect transitions were observed when the CDQW was subjected to modest bias voltages.

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.


1994 ◽  
Vol 49 (8) ◽  
pp. 5434-5437 ◽  
Author(s):  
Shi-rong Jin ◽  
Zhong-ying Xu ◽  
Jin-sheng Luo

1991 ◽  
Vol 228 ◽  
Author(s):  
H. Luo ◽  
N. Samarth ◽  
J. K. Furdyna ◽  
H. Jeon ◽  
J. Ding ◽  
...  

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.


Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 1006
Author(s):  
Hongqiang Li ◽  
Jianing Wang ◽  
Jinjun Bai ◽  
Shanshan Zhang ◽  
Sai Zhang ◽  
...  

The realization of a fully integrated group IV electrically driven laser at room temperature is an essential issue to be solved. We introduced a novel group IV side-emitting laser at a wavelength of 1550 nm based on a 3-layer Ge/Si quantum well (QW). By designing this scheme, we showed that the structural, electronic, and optical properties are excited for lasing at 1550 nm. The preliminary results show that the device can produce a good light spot shape convenient for direct coupling with the waveguide and single-mode light emission. The laser luminous power can reach up to 2.32 mW at a wavelength of 1550 nm with a 300-mA current. Moreover, at room temperature (300 K), the laser can maintain maximum light power and an ideal wavelength (1550 nm). Thus, this study provides a novel approach to reliable, efficient electrically pumped silicon-based lasers.


1999 ◽  
Vol 30 (4-5) ◽  
pp. 433-437 ◽  
Author(s):  
J.M Feng ◽  
M Tateuchi ◽  
K Asai ◽  
M Uwani ◽  
P.O Vaccaro ◽  
...  

1987 ◽  
Vol 102 ◽  
Author(s):  
Y. J. Chen ◽  
Emil S. Koteles ◽  
B. Elman ◽  
C. A. Armiento

ABSTRACTWe present a detailed experimental study of the influence of electric fields on exciton states in a GaAs/AlGaAs coupled double quantum well structure and discuss the advantages of using this novel structure. The coupling of electronic states in the two quantum wells, due to the narrowness of the barrier between them, leads to an enhancement of the quantum-confined Stark effect (by as much as five times that of the single quantum well case). From the measured energies of the exciton transitions, splittings of the levels in a coupled double quantum well structure were derived without recourse to a theoretical model.


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