Band edge alignment of pseudomorphic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>GaAs</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>y</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>Sb</mml:mi><mml:mi>y</mml:mi></mml:msub></mml:mrow></mml:math>on GaAs

Wang, J.-B.; Johnson, Shane; Chaparro, S. A.; Ding, Ding; Cao, Yu; Sadofyev, Yu. G.; Zhang, Yong-Hang; Gupta, J. A.; Guo, Chengchen

doi:10.1103/physrevb.70.195339

Cited by 58 publications

(29 citation statements)

References 25 publications

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“…Fundamental issues regarding their growth process, energy level structure, and optical properties in addition to their technological applications in photodetection and photovoltaics have been already investigated in different configurations such as quantum dots ͑QDs͒, 1-5 quantum wells 6 ͑QWs͒ or ternary compounds. 7 In this work, we present various results regarding the GaSb/ GaAs QDs system, which extend and complete previous works.The QDs studied here were grown by solid source molecular beam epitaxy on a n-type GaAs͑001͒ substrate after deposition of a n-type GaAs buffer layer ͑Si: 1 ϫ 10 18 cm −2 ͒. The QDs were nucleated at 480°C, using a growth rate of 0.1 ML/ s. The formation of the GaSb QDs was detected by the change of the reflection high energy electron diffraction pattern after the deposition of 1.3 ML of GaSb.…”

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confidence: 62%

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Optical investigation of type II GaSb∕GaAs self-assembled quantum dots

Alonso-Álvarez¹,

Alén²,

García³

et al. 2007

Applied Physics Letters

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We have studied the emission and absorption properties of type II GaSb/ GaAs quantum dots embedded in a p-i-n photodiode. The excitation power evolution provides clear signatures of the spatially separated confinement of electrons and holes in these nanostructures. We have estimated the confinement potential for the holes to be ϳ500 meV, leading to an intense room temperature emission assisted by recapture processes from the wetting layer. Photocurrent measurements show strong absorption in the wetting layer and in the quantum dots at room temperature which are important for photodetection applications based in this system. © 2007 American Institute of Physics. ͓DOI: 10.1063/1.2827582͔In recent years, GaSb/ GaAs structures have aroused great interest due to their type II band alignment and intrinsically different behavior compared to the well known InAs/ GaAs system. Fundamental issues regarding their growth process, energy level structure, and optical properties in addition to their technological applications in photodetection and photovoltaics have been already investigated in different configurations such as quantum dots ͑QDs͒, 1-5 quantum wells 6 ͑QWs͒ or ternary compounds. 7 In this work, we present various results regarding the GaSb/ GaAs QDs system, which extend and complete previous works.The QDs studied here were grown by solid source molecular beam epitaxy on a n-type GaAs͑001͒ substrate after deposition of a n-type GaAs buffer layer ͑Si: 1 ϫ 10 18 cm −2 ͒. The QDs were nucleated at 480°C, using a growth rate of 0.1 ML/ s. The formation of the GaSb QDs was detected by the change of the reflection high energy electron diffraction pattern after the deposition of 1.3 ML of GaSb. The GaSb layer, with a nominal thickness of 2 ML, was then exposed to Sb flux for 20 s and then annealed for 20 s without an Sb flux to limit the amount of Sb segregated during capping. The GaAs capping was done at 0.4 ML/ s in two steps. In the first step, a 10 nm thick GaAs layer was grown at the temperature of QD nucleation to avoid their destabilization. In the second one, a 40 nm thick GaAs layer was deposited at 570°C. During growth, the As and Sb beam equivalent pressures were 1.0ϫ 10 −5 and 1.9ϫ 10 −6 mbar, respectively. This scheme was repeated six times, with a 3 min growth interruption under an As 4 flux to lower the substrate temperature before the nucleation of the next QD layer. On top, a p-type 300 nm thick GaAs layer ͑Be: 1 ϫ 10 18 cm −2 ͒ was grown at 580°C. Finally, standard optical lithography and wet etching techniques were used to define mesas and metal Ohmic contacts. Figure 1͑a͒ shows the photoluminescence ͑PL͒ spectra recorded at 20 K as a function of excitation power at 532 nm. We can clearly identify two bands centered at 1.32 and 1.05 eV. The narrow high energy band corresponds to the wetting layer ͑WL͒ recombination and dominates the spectrum at low temperatures. Its peak energy position is compatible with a GaSb WL thickness of 0.7 nm, 2 which is larger than the total amount of GaSb deposited ͑0.57 nm͒...

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confidence: 62%

supporting

confidence: 62%

Optical investigation of type II GaSb∕GaAs self-assembled quantum dots

Alonso-Álvarez¹,

Alén²,

García³

et al. 2007

Applied Physics Letters

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“…GaAsSb and GaSb growth are also used for manufacturing photoconductive THz emitters [118][119][120], THz laser [121] and double HBT structure [122]. GaAsSb/GaAs quantum wells have attracted attention for their potential applications in electronic and optoelectronic devices, and these structures have been fabricated and evaluated in several reports [123][124][125][126][127][128][129][130][131]. In addition, an undoped GaAsSb quantum well was grown by MLE on undoped semi-insulating (100), (111)A, (111)B and (110) GaAs substrates using trimethylantimonide [132].…”

Section: Gaassb Quantum Well and Gasb Dot Growth For Thz Devicesmentioning

confidence: 99%

Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

Ohno

Oyama

2012

Science and Technology of Advanced Materials

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In this article we review the fundamental properties and applications of sidewall GaAs tunnel junctions. Heavily impurity-doped GaAs epitaxial layers were prepared using molecular layer epitaxy (MLE), in which intermittent injections of precursors in ultrahigh vacuum were applied, and sidewall tunnel junctions were fabricated using a combination of device mesa wet etching of the GaAs MLE layer and low-temperature area-selective regrowth. The fabricated tunnel junctions on the GaAs sidewall with normal mesa orientation showed a record peak current density of 35 000 A cm −2 . They can potentially be used as terahertz devices such as a tunnel injection transit time effect diode or an ideal static induction transistor.

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“…The devices were measured as-cleaved with different cavity lengths. Further details on the growth and fabrication can be found in [6,7]. Temperature dependence measurements over the range of 60-300 K were performed with a standard closed cycle cryostat set-up.…”

Section: Laser Structure and Experimentsmentioning

confidence: 99%

Improved performance of GaAsSb/GaAs SQW lasers

Hossain

Jin

Sweeney

et al. 2010

Novel in-Plane Semiconductor Lasers IX

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This paper reports the improvements and limitations of MBE grown 1.3μm GaAsSb/GaAs single QW lasers. At room temperature, the devices show a low threshold current density (J th ) of 253 Acm -2 , a transparent current density of 98 Acm -2 , an internal quantum efficiency of 71%, an optical loss of 18 cm -1 and a characteristic temperature (T 0 ) = 51K. The defect related recombination in these devices is negligible and the primary non-radiative current path has a stronger dependence on the carrier density than the radiative current contributing to ~84% of the threshold current at RT. From high hydrostatic pressure dependent measurements, a slight decrease followed by the strong increase in threshold current with pressure is observed, suggesting that the device performance is limited to both Auger recombination and carrier leakage.

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Band edge alignment of pseudomorphicGaAs1−ySbyon GaAs

Cited by 58 publications

References 25 publications

Optical investigation of type II GaSb∕GaAs self-assembled quantum dots

Optical investigation of type II GaSb∕GaAs self-assembled quantum dots

Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

Improved performance of GaAsSb/GaAs SQW lasers

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