Investigation of optical properties of In(Ga)As/GaAs mesa structures with active region based on quantum wells, quantum dots, and quantum well-dots

ABSTRACTIn this paper we studied the thermoelectric power under classically large magnetic field (TPM) in quantum wells (QWs), quantum well wires (QWWS) and quantum dots (QDs) of Bi by formulating the respective electron dispersion laws. The TPM increases with increasing film thickness in an oscillatory manner in all the cases. The TPM in QD is greatest and the least for quantum wells respectively. The theoretical results are in agreement with the experimental observations as reported elsewhere.

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LINEAR AND NONLINEAR INTERSUBBAND OPTICAL ABSORPTION OF FINITE AND INFINITE SEMI-PARABOLIC QUANTUM WELLS

Modern Physics Letters B ◽

10.1142/s0217984911025882 ◽

2011 ◽

Vol 25 (07) ◽

pp. 497-507 ◽

Cited By ~ 1

Author(s):

M. J. KARIMI ◽

A. KESHAVARZ ◽

A. POOSTFORUSH

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Optical Absorption ◽

Quantum Well ◽

Quantum Wells ◽

Resonant Peak ◽

Energy Eigenvalues ◽

Finite Case ◽

Infinite Case ◽

Index Changes

In this work, the optical absorption coefficients and the refractive index changes for the infinite and finite semi-parabolic quantum well are calculated. Numerical calculations are performed for typical GaAs / Al x Ga 1-x As semi-parabolic quantum well. The energy eigenvalues and eigenfunctions of these systems are calculated numerically. Optical properties are obtained using the compact density matrix approach. Results show that the energy eigenvalues and the matrix elements of the infinite and finite cases are different. The calculations reveal that the resonant peaks of the optical properties of the finite case occur at lower values of the incident photon energy with respect to the infinite case. Results indicate that the maximum value of the refractive index changes for the finite case are greater than that of the infinite case. Our calculations also show that in contrast to the infinite case, the resonant peak value of the total absorption coefficient in the case of the finite well is a non-monotonic function of the semi-parabolic confinement frequency.

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Stacked Dual-Band Quantum Well Infrared Photodetector Based on Double-Layer Gold Disk Enhanced Local Light Field

Nanomaterials ◽

10.3390/nano11102695 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2695

Author(s):

Chang Liu ◽

Xuan Zuo ◽

Shaohui Xu ◽

Lianwei Wang ◽

Dayuan Xiong

Keyword(s):

Active Region ◽

Quantum Well ◽

Quantum Wells ◽

Double Layer ◽

Enhancement Factor ◽

Coupling Efficiency ◽

Dual Band ◽

Enhancement Effect ◽

Infrared Photodetector ◽

Quantum Well Infrared Photodetector

We propose a stacked dual-band quantum well infrared photodetector (QWIP) integrated with a double-layer gold disk. Two 10-period quantum wells (QW) operating at different wavelengths are stacked together, and gold nano-disks are integrated on their respective surfaces. Numerical calculations by finite difference time domain (FDTD) showed that the best enhancement can be achieved at 13.2 and 11.0 µm. By integrating two metal disks, two plasmon microcavity structures can be formed with the substrate to excite localized surface plasmons (LSP) so that the vertically incident infrared light can be converted into electric field components perpendicular to the growth direction of the quantum well (EZ). The EZ electric field component can be enhanced up to 20 times compared to the incident light, and it is four times that of the traditional two-dimensional hole array (2DHA) grating. We calculated the enhancement factor and coupling efficiency of the device in the active region of the quantum well. The enhancement factor of the active region of the quantum well on the top layer remains above 25 at the wavelength of 13.2 μm, and the enhancement factor can reach a maximum of 45. Under this condition, the coupling efficiency of the device reaches 2800%. At the wavelength of 11.0 μm, the enhancement factor of the active region of the quantum well at the bottom is maintained above 6, and the maximum can reach about 16, and the coupling efficiency of the device reaches 800%. We also optimized the structural parameters and explored the influence of structural changes on the coupling efficiency. When the radius (r1, r2) of the two metal disks increases, the maximum coupling efficiency will be red-shifted as the wavelength increases. The double-layer gold disk structure we designed greatly enhances the infrared coupling of the two quantum well layers working at different wavelengths in the dual-band quantum well infrared photodetector. The structure we designed can be used in stacked dual-band quantum well infrared photodetectors, and the active regions of quantum wells working at two wavelengths can enhance the photoelectric coupling, and the enhancement effect is significant. Compared with the traditional optical coupling structure, the structure we proposed is simpler in process and has a more significant enhancement effect, which can meet the requirements of working in complex environments such as firefighting, night vision, and medical treatment.

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Optical properties of GaSb-based type II quantum wells as the active region of midinfrared interband cascade lasers for gas sensing applications

Applied Physics Letters ◽

10.1063/1.3157910 ◽

2009 ◽

Vol 94 (25) ◽

pp. 251901 ◽

Cited By ~ 20

Author(s):

M. Motyka ◽

G. Sęk ◽

K. Ryczko ◽

J. Misiewicz ◽

T. Lehnhardt ◽

...

Keyword(s):

Optical Properties ◽

Active Region ◽

Quantum Wells ◽

Gas Sensing ◽

Type Ii ◽

Sensing Applications ◽

Type Ii Quantum Wells ◽

Interband Cascade Lasers ◽

Cascade Lasers

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Multi-quantum-well quantum dots with stable dual emission

Nanoscale ◽

10.1039/c9nr00177h ◽

2019 ◽

Vol 11 (17) ◽

pp. 8475-8484 ◽

Cited By ~ 3

Author(s):

Weishuo Xing ◽

Xinsu Zhang ◽

Chong Geng ◽

Yangyang Xie ◽

Yuchen Deng ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Well ◽

Quantum Wells ◽

Excitation Power ◽

Dual Emission ◽

Multi Quantum Well ◽

Exciton Distribution

MQW-QDs with stable dual emission versus excitation power are achieved via balancing exciton distribution in adjacent quantum wells.

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1.5 micron InAs quantum dot lasers based on metamorphic InGaAs/GaAs heterostructures.

MRS Proceedings ◽

10.1557/proc-794-t7.2/z7.2 ◽

2003 ◽

Vol 794 ◽

Author(s):

V.M. Ustinov ◽

A.E. Zhukov ◽

A.R. Kovsh ◽

N.A. Maleev ◽

S.S. Mikhrin ◽

...

Keyword(s):

Quantum Dots ◽

Active Region ◽

Quantum Wells ◽

Gaas Substrate ◽

Room Temperature ◽

Internal Quantum Efficiency ◽

Characteristic Temperature ◽

Optical Loss ◽

Threshold Current ◽

Temperature Threshold

ABSTRACT1.5 micron range emission has been realized using the InAs quantum dots embedded into the metamorphic InGaAs layer containing 20% of InAs grown by MBE on a GaAs substrate. Growth regimes were optimized to reduce significantly the density of dislocations propagating into the active layer from the lattice mismatched interface. 2 mm long InGaAs/InGaAlAs lasers with 10 planes of quantum dots in the active region showed threshold current density about 1.4 kA/cm2 with the external differential efficiency as high as 38%. Lasing wavelength depends on the optical loss being in the 1.44–1.49 micron range at room temperature. On increasing the temperature the wavelength reaches 1.515 micron at 85C while the threshold current characteristic temperature of 55–60K was estimated. High internal quantum efficiency (η>60%)and low internal losses (α=3–4 cm ) were realized. Maximum room temperature output power in pulsed regime as high as 5.5 W for 100 micron wide stripe was demonstrated. Using the same concept 1.3 micron InGaAs/InGaAlAs quantum well lasers were fabricated. The active region contained quantum wells with high (∼40%) indium content which was possible due to the intermediate InGaAs strain relaxation layer. 1 mm stripe lasers showed room temperature threshold current densities about 3.3 kA/cm (λ=1.29 micron) and 400 A/cm2 at 85K. Thus, the use of metamorphic InGaAs layers on GaAs substrate is a very promising approach for increasing the emission wavelength of GaAs based lasers.

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Optical properties of CdTe∕ZnTe quantum dots sandwiched between two quantum wells with ZnTe separation barriers

Applied Physics Letters ◽

10.1063/1.2385114 ◽

2006 ◽

Vol 89 (18) ◽

pp. 181929 ◽

Cited By ~ 9

Author(s):

H. S. Lee ◽

H. L. Park ◽

T. W. Kim

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Quantum Wells

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Modeling of elastic, piezoelectric and optical properties of vertically correlated GaN/AlN quantum dots

MRS Proceedings ◽

10.1557/proc-831-e11.14 ◽

2004 ◽

Vol 831 ◽

Cited By ~ 1

Author(s):

Sławomir P. Łepkowski ◽

Grzegorz Jurczak ◽

Paweł Dłużewski ◽

Tadeusz Suski

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Quantum Dot ◽

Quantum Wells ◽

Electrostatic Potential ◽

Barrier Width ◽

Base Diameter ◽

Transition Energies ◽

Band Transition ◽

Hexagonal Pyramid

ABSTRACTWe theoretically investigate elastic, piezoelectric and optical properties of wurtzite GaN/AlN quantum dots, having hexagonal pyramid-shape, stacked in a multilayer. We show that the strain existing in quantum dots and barriers depends significantly on the distance between the dots i.e. on the width of AlN barriers. For typical QDs, having the base diameter of 19.5nm, the drop of the electrostatic potential in the quantum dot region slightly decreases with decreasing of the barrier width. This decrease is however much smaller for QDs than for superlattice of GaN/AlGaN quantum wells, with thickness similar to the height of QDs. Consequently, the band-to-band transition energies in the vertically correlated GaN/AlN QDs show unexpected, rather weak dependence on the width of AlN barriers. Increasing the QD base diameter leads to stronger decreasing dependence of the band-to-band transition energies vs. the width of AlN barriers, similar to that observed for superlattieces of QWs.

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Structural and Optical Properties of Nitride-Based Heterostructure and Quantum-Well Structure

MRS Proceedings ◽

10.1557/proc-449-1143 ◽

1996 ◽

Vol 449 ◽

Cited By ~ 39

Author(s):

H. Amano ◽

T. Takeuchi ◽

S. Sota ◽

H. Sakai ◽

I. Akasaki

Keyword(s):

Optical Properties ◽

Quantum Well ◽

Quantum Wells ◽

Stark Effect ◽

Compressive Strain ◽

Ternary Alloys ◽

Luminescence Properties ◽

Structural And Optical Properties ◽

Quantum Confined Stark Effect ◽

Quantum Well Structure

ABSTRACTStructural and optical properties of nitride based heterostructure and quantum well structure were investigated. Both AIGaN and GaInN ternary alloys are found to grow coherently on the underlying GaN layer. Compressive strain of GaInN is found to cause quantum confined Stark effect, thus affects the luminescence properties of nitride-based quantum wells.

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