Calculation of strain compensation thickness for III–V semiconductor quantum dot superlattices

Polly, Stephen J.; Bailey, Christopher G.; Grede, Alex J.; Forbes, David V.; Hubbard, Seth M.

doi:10.1016/j.jcrysgro.2016.08.050

Cited by 17 publications

(8 citation statements)

References 20 publications

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“…The detailed description of substrate treatment and the GaSb buffer layer deposition procedure can be found elsewhere [14], [15]. The LWIR range was reached by growing 9.99 nm period "Ga-free" T2SLs (InAs 7.58 nm/InAsSb 2.41 nm, x Sb = 0.38), where the layer thicknesses were simulated according to the approach given by Polly et al [16].…”

Section: Sample Preparation and Device Structurementioning

confidence: 99%

Demonstration of the Longwave Type-II Superlattice InAs/InAsSb Cascade Photodetector for High Operating Temperature

Gawron

Kubiszyn

Michalczewski

et al. 2022

IEEE Electron Device Lett.

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This letter presents InAs/InAsSb-based superlattice (SL) long wavelength (8-12 μm) range (LWIR) cascade photodetector operating at temperatures > 190 K. The design of the detector resolves the problem of the low quantum efficiency (QE ) and resistance of the traditional photovoltaic detectors optimized for high temperature (HOT) conditions. The device was deposited by molecular beam epitaxy (MBE) on GaAs substrates with type-II InAs/InAsSb superlattice (T2SLs) absorbers. The constituent stages of the cascade are connected by the low resistance tunnel junctions. Detectivity (D * ) of the unbiased device reaches ∼ 6.7 × 10 8 cmHz 1/2 /W at 210 K, λ = 10 μm.

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Section: Sample Preparation and Device Structurementioning

confidence: 99%

Demonstration of the Longwave Type-II Superlattice InAs/InAsSb Cascade Photodetector for High Operating Temperature

Gawron

Kubiszyn

Michalczewski

et al. 2022

IEEE Electron Device Lett.

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“…Here 𝐶 12 𝑆𝐿 and 𝐶 11 𝑆𝐿 are the weighted averages of the elastic constants of the individual unstrained CdTe and ZnCdSe layers given by 18 :…”

Section: Growthmentioning

confidence: 99%

Advanced material system for the design of an intermediate band solar cell: Type-II CdTe quantum dots in a ZnCdSe matrix

Deligiannakis

Ranepura

Kuskovsky

et al. 2019

Journal of Applied Physics

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We explore CdTe fractional monolayer quantum dots (QDs) in a ZnCdSe host matrix for potential application in an intermediate band solar cell device. Careful consideration has been taken during the initiation of the growth process of QDs by migration enhanced epitaxy, in order to avoid the formation of undesirable interfacial layers that can form due to the lack of common anion between the two materials. A superlattice structure of 100 periods of alternating QD and spacer layers is analyzed by high resolution X-ray diffraction (XRD) and photoluminescent (PL) spectroscopy. Simple arguments are used following continuum elastic theory to deduce the size of the dots and the strain within the superlattice from XRD data. This is further verified using PL and used in the energy calculations that yield the values of the intermediate band energy. The results suggest that the optimized materials are highly suitable for these high efficiency solar cells.

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“…The SBQW region is inserted into the junction depletion region, surrounded on both sides by intrinsic layers of GaAs without intentional doping. The In x Ga 1-x As quantum wells are also undoped and strain balanced with GaAs 0.90 P 0.10 barrier layers [18], [19]. Thin 1 nm GaAs transition layers are inserted at each As-P interface in the well region.…”

Section: Device Structures and Experimental Detailsmentioning

confidence: 99%

Impact of Well Number on High-Efficiency Strain-Balanced Quantum-Well Solar Cells

Welser

Polly

Bogner

et al. 2023

IEEE J. Photovoltaics

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The addition of lower energy-gap InGaAs quantum wells to the depletion region of GaAs solar cells is an established approach to enhance photovoltaic performance by extending infrared collection. However, maintaining a high open-circuit voltage (V oc ) when including quantum wells has proven more challenging. In this article, we report on high-efficiency (η > 23.5% AM0) strainbalanced quantum well (SBQW) solar cells with increased current output and efficiency while maintaining the same high open-circuit voltage of baseline devices without quantum wells (V oc > 1.02 V). The single-junction GaAs-based device structures discussed herein employ a radiation-tolerant, n-i-p front-junction architecture and include both an InGaP heterojunction (HJ) emitter and in most cases an underlying AlGaAs distributed Bragg reflector.The impact of well number on photovoltaic device characteristics is described using an analytical model that assumes current collection, radiative recombination, and nonradiative recombination all increase with well number and are additive to the baseline cell. The highest V oc and efficiency SBQW devices employ shallow 9.2 nm In 0.07 Ga 0.93 As quantum wells and 11.5 nm GaAs 0.90 P 0.10 barrier layers to maintain strain balancing. Increasing the indium composition in the wells from 7% to 10% to form deeper wells requires a thicker strain-balancing barrier layer and results in an apparent increase in radiative recombination and decreased V oc . Single-junction high-efficiency SBQW device performance is also demonstrated in thinner base-layer structures with graded HJs-device structures suitable for inclusion in radiation-tolerant multi-junction structures.

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Calculation of strain compensation thickness for III–V semiconductor quantum dot superlattices

Cited by 17 publications

References 20 publications

Demonstration of the Longwave Type-II Superlattice InAs/InAsSb Cascade Photodetector for High Operating Temperature

Demonstration of the Longwave Type-II Superlattice InAs/InAsSb Cascade Photodetector for High Operating Temperature

Advanced material system for the design of an intermediate band solar cell: Type-II CdTe quantum dots in a ZnCdSe matrix

Impact of Well Number on High-Efficiency Strain-Balanced Quantum-Well Solar Cells

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