Photoluminescence In Strain Compensated Siisigec Multiple Quantum Wells

1998 ◽  
Vol 533 ◽  
Author(s):  
R. Hartmann ◽  
U. Gennser ◽  
D. Grützmacher ◽  
H. Sigg ◽  
E. Müller ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Band Gap ◽  
Valence Band ◽  
Band Alignment ◽  
Multiple Quantum ◽  
Type I ◽  
Strain Compensation ◽  
Quantum Well States ◽  
Good Agreement

AbstractThe effect of strain compensation on the band gap and band alignment of Si/SiGeC MQWs is studied by photoluminescence (PL) spectroscopy. Evidence for type-I band alignment of strain reduced SiGeC MQWs is found. Values for the conduction and valence band offsets are given. A band gap reduction for exactly strain compensated SiGeC compared to compressive SiGeC is observed. This behavior is interpreted in terms of strain induced splitting and confinement shifts of the quantum well states. A good agreement between the model and the PL data is obtained.

Band Alignment of Si1-xGex And Si1-x-y.GexCy Quantum Wells On Si (001)

1998 ◽  
Vol 533 ◽  
Author(s):  
N. L. Rowell ◽  
R. L. Williams ◽  
G. C. Aers ◽  
H. Lafontaine ◽  
D. C. Houghton ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Applied Stress ◽  
Vapour Deposition ◽  
Stress Condition ◽  
High Vacuum ◽  
Chemical Vapour ◽  
Band Alignment ◽  
Ultra High Vacuum ◽  
Multiple Quantum ◽  
Type I

AbstractRecent low-temperature photoluminescence (PL) studies will be discussed for coherent Si1-xGex. and Si1-xGexCy alloy multiple quantum wells on Si (001) substrates grown by either ultra-high vacuum chemical vapour deposition or solid source molecular beam epitaxy. An in-plane applied-stress technique will be described which removes systematically band edge degeneracies revealing the lower, PL-active CB. Applied-stress data taken with this technique at ultra-low excitation intensity proved intrinsic type II CB alignment in SiGe on Si (001). Apparent type I alignment observed at higher intensity will also be discussed. New applied stress PL results are presented for Si1-x-yGexCy quantum wells under various grown-in stress condition

scholarly journals Effects of Variation of Quantum Well Numbers on Gain Characteristics of Type-I InGaAsP/InP Nano-heterostructure

2017 ◽  
Vol 6 (3) ◽  
pp. 301-310
Author(s):  
S. G. Anjum ◽  
Sandhya K. ◽  
A. B. Khan ◽  
A. M. Khan ◽  
M. J. Siddiqui ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Carrier Density ◽  
Multiple Quantum ◽  
Type I ◽  
Long Distance ◽  
Single Quantum Well ◽  
Lasing Wavelength ◽  
Material Gain ◽  
Distance Communication

This paper reports the effects of variation of number of quantum wells in material gain characteristics and lasing wavelength of step index separately confined type-I InGaAsP/InP lasing nano-heterostructure for different carrier concentrations at room temperature in TE (Transverse Electric) mode of polarization. Peak material gain is found to be highest when the number of quantum well is one in the structure. However, for the case of 3QWs, 5QWs and 7QWs, it is almost same at a particular carrier density. Lasing wavelength at peak material gain considerably increases as the number of quantum well layers vary from single quantum well layer to three quantum well layers in the active region and after that it will remain almost same by any further increase in number of quantum wells for a particular carrier density. Furthermore, negative gain condition in the material gain spectra exists in the case of multiple quantum wells only at carrier concentration of 2×1018/cm3. The results suggest that the proposed nano-heterostructure is highly suitable as a light source in fiber optic links for long distance communication.

X-Ray Scattering (Modeling and Experiment) of InxGa1-xAs/GaAs Multiple Quantum Wells

1987 ◽  
Vol 103 ◽  
Author(s):  
Jichai Jeong ◽  
J. C. Lee ◽  
M. A. Shahid ◽  
T. E. Schlesinger ◽  
A. G. Milnes
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Good Agreement

ABSTRACTX-ray diffraction, transmission electron microscopy (TEM), and photoluminescence measurements have been made on strained InxGa1-xAs/GaAs quantum well structures. The well widths measured from TEM are 187, 115 and 69 Å for an interrupted growth, and 218, 126, 60 Å for a non-interrupted growth. In the measured x-ray diffraction patterns, the Pendellosung fringes due to GaAs barriers are modulated by a broad weak peak mostly coming from the thickest InxGa1-xAs well layer and is fairly symmetric for the noninterrupted sample. For the interrupted quantum well, the x-ray diffraction pattern is less symmetric, since there is further modulation by another broader and weaker peak. This results show that the In content in the InxGa1-xAs well layers are not well controlled for the interrupted quantum well. Using actual thickness measured from TEM, x-ray diffraction patterns are calculated and good agreement is obtained between the measured and the calculated x-ray diffraction patterns. The three strained InxGa1-xAs/Gaks quantum wells grown without interruption produce high intensity and narrow full-width at half-maximum (FWHIM) of 2.9 meV of the photoluminescence peak. The photoluminescence peaks for the interrupted quantum well are relatively broad and asymmetric, and have lower intensities, indicating that better quality InxGa1-xAs/GaAs quantum wells can be grown without interruption.

Recombination and spin dynamics of excitons in thin (Ga,Al)(Sb,As)/AlAs quantum wells with an indirect band gap and type-I band alignment

2020 ◽  
Vol 102 (16) ◽  
Author(s):  
T. S. Shamirzaev ◽  
D. R. Yakovlev ◽  
A. K. Bakarov ◽  
N. E. Kopteva ◽  
D. Kudlacik ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Spin Dynamics ◽  
Band Alignment ◽  
Type I ◽  
Indirect Band Gap

scholarly journals Characterization of band gap in GaAsSb/GaAs heterojunction and band alignment in GaAsSb/GaAs multiple quantum wells

2008 ◽  
Vol 147 (2-3) ◽  
pp. 131-135 ◽  
Author(s):  
T.S. Wang ◽  
J.T. Tsai ◽  
K.I. Lin ◽  
J.S. Hwang ◽  
H.H. Lin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Band Alignment ◽  
Multiple Quantum Wells ◽  
Multiple Quantum

Characterisation of multilayer materials using a position-sensitive atom probe

1990 ◽  
Vol 48 (4) ◽  
pp. 624-625
Author(s):  
RAD Mackenzie ◽  
G D W Smith ◽  
A. Cerezo ◽  
J A Liddle ◽  
CRM Grovenor ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Information ◽  
Chemical Vapour ◽  
Atom Probe ◽  
Organic Chemical ◽  
Growth Stages ◽  
Multiple Quantum ◽  
Quartz Wool ◽  
Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

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