Optical tuning of the charge carrier type in the topological regime of InAs/GaSb quantum wells

Knebl, Georg; Pfeffer, P.; Schmid, Sebastian; Kamp, M.; Bastard, G.; Batke, E.; Worschech, L.; Hartmann, Fabian; Höfling, Sven

doi:10.1103/physrevb.98.041301

Cited by 8 publications

(6 citation statements)

References 39 publications

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“…The so called 6.1 Å family, which is comprised of the three semiconductors InAs, GaSb, and AlSb offers a huge flexibility in designing electronic, optical, and optoelectronic devices, such as topological insulators, optical MIR type‐II superlattice photodetectors, and quantum cascade lasers (QCLs), or interband cascade lasers (ICLs), and interband cascade detectors (ICDs) . This flexibility can mainly be attributed to the huge variety of band lineups, bandgap energies, and in particular to the so called InAs/GaSb type‐II broken bandgap alignment.…”

Section: Introductionmentioning

confidence: 99%

p‐Type Doped AlAsSb/GaSb Resonant Tunneling Diode Photodetector for the Mid‐Infrared Spectral Region

Pfenning

Hartmann

Weih

et al. 2018

Advanced Optical Materials

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In a recent publication, we proposed to apply the resonant tunneling diode (RTD) photodetector principle to the mid-infrared (MIR) spectral region, by combining an antimony-based AlSb/ GaSb double barrier quantum well (DBQW) resonant tunneling structure (RTS) with an narrow bandgap absorption region. [17] Hereby, the RTD serves as an internal high-gain amplifier of small optically generated electrical signals. In contrast to, e.g., avalanche photodiodes where the gain is provided via impact ionization processes, the gain of RTD photodetectors originates from the modulation of a larger majority charge carrier tunneling current that is sensitive to small variations of the local electrostatic potential.The so called 6.1 Å family, [18] which is comprised of the three semiconductors InAs, GaSb, and AlSb offers a huge flexibility in designing electronic, optical, and optoelectronic devices, [19] such as topological insulators, [20][21][22][23] optical MIR type-II superlattice photodetectors, [24] and quantum cascade lasers (QCLs), [25][26][27] or interband cascade lasers (ICLs), [27][28][29][30][31] and interband cascade detectors (ICDs). [32,33] This flexibility can mainly be attributed to the huge variety of band lineups, bandgap energies, and in particular to the so called InAs/GaSb type-II broken bandgap alignment. While the InAs/GaSb/AlSb material system has also brought forth a large variety of different resonant tunneling structures, [3,18,34,35] only AlAsSb/GaSb RTDs provide the required energy barriers in both valence and conduction band due to the type-I heterointerface. [36][37][38][39] In another recent publication, we demonstrated that room temperature resonant tunneling of electrons in AlAsSb/GaSb RTDs requires the use of emitter prewells. [40][41][42] Here, we propose to invert the charge carrier polarity within the RTD photodetector, i.e., using p-type instead of n-type doping.Using p-type doping in an RTD photodetector, and therefore hole instead of electron transport, might seem counterintuitive at first, since hole transport usually comes with several disadvantages. Due to their higher effective mass, holes have a lower mobility and a smaller de Broglie wavelength compared to electrons. [43] A lower mobility results in inferior transport properties, a smaller de Broglie wavelength demands a higher quality semiconductor crystal growth. However, and in particular for the GaSb material system, p-type doping may Mid-infrared (MIR) resonant tunneling diode (RTD) photodetectors based on a p-type doped AlAsSb/GaSb double-barrier quantum well (DBQW) are proposed and investigated for their optoelectronic transport properties. At room temperature, a distinct resonant tunneling current with a region of negative differential conductance is measured. The peak-to-valley current ratio (PVCR) is 1.51. To provide photosensitivity within the MIR spectral region, a lattice-matched quaternary low-bandgap GaInAsSb absorption layer with cutoff wavelength of λ = 2.77 μm is integrated near the DBQW. Under illumination with ...

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Section: Introductionmentioning

confidence: 99%

p‐Type Doped AlAsSb/GaSb Resonant Tunneling Diode Photodetector for the Mid‐Infrared Spectral Region

Pfenning

Hartmann

Weih

et al. 2018

Advanced Optical Materials

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“…[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] Many optical experiments have also been carried out in the InAs/GaSb quantum well systems. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] In the earlier experiments, the quantum well had a high electron density. In recent years, as the material growth technology progresses, the sample quality increases greatly.…”

Section: Introductionmentioning

confidence: 96%

“…In the case of a perpendicular magnetic field, or of a tilted magnetic field, the magneto-optical properties of the InAs/GaSb quantum well have been investigated, both experimentally and theoretically. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][37][38][39][40][41] There were also some theoretical study on the transport property of the InAs/GaSb quantum well in the presence of an in-plane magnetic field based on a generalized or extended two-dimensional topological insulator model. [42][43][44] Our theoretical result shows that, as the strength of the in-plane magnetic field increases, the de-polarization effect originated from the electron-electron interaction in the InAs/GaSb quantum well becomes more important, and the in-plane optical response of the quantum well becomes asymmetrical.…”

Section: Introductionmentioning

confidence: 99%

Optical response of an inverted InAs/GaSb quantum well in an in-plane magnetic field*

Wu¹

2019

Chinese Phys. B

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The optical response of an inverted InAs/GaSb quantum well is studied theoretically. The influence of an in-plane magnetic field that is applied parallel to the quantum well is considered. This in-plane magnetic field will induce a dynamical polarization even when the electric field component of the external optical field is parallel to the quantum well. The electron–electron interaction in the quantum well system will lead to the de-polarization effect. This effect is found to be important and is taken into account in the calculation of the optical response. It is found that the main feature in the frequency dependence of the velocity–velocity correlation function remains when the velocity considered is parallel to the in-plane magnetic field. When the direction of the velocity is perpendicular to the in-plane magnetic field, the de-polarization effect will suppress the oscillatory behavior in the corresponding velocity–velocity correlation function. The in-plane magnetic field can change the band structure of the quantum well drastically from a gapped semiconductor to a no-gapped semi-metal, but it is found that the distribution of the velocity matrix elements or the optical transition matrix elements in the wave vector space has the same two-tadpole topology.

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“…Thus, in contrast to the prototypal TI based on HgTe/CdTe quantum wells, a tuning between a trivial and topological phase by a dual gating approach in InAs/GaSb BQWs makes the material system interesting for potential device applications [2] such as topological transistors. However, despite extensive studies on InAs/GaSb BQWs and indications for helical edge transport a fully convincing demonstration of these helical edge states is still elusive [3][4][5][6][7][8][9]. By adding another InAs-layer to the BQW, a symmetrical InAs/GaSb/InAs trilayer quantum well (TQW) can be formed [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Voltage control of the quantum scattering time in InAs/GaSb/InAs trilayer quantum wells

et al. 2023

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We study the evolution of the quantum scattering time by gate voltage training in the topological insulator based on InAs/GaSb/InAs trilayer quantum wells. Depending on the minimal gate voltage applied during a gate voltage sweep cycle, the quantum scattering time can be improved by 50 % from 0.08 ps to 0.12 ps albeit the transport scattering time is rather constant around 1.0 ps. The ratio of the quantum scattering time versus transport scattering time scales linearly with the charge carrier density and varies from 10 to 30, indicating Coulombic scattering as the dominant scattering mechanism. Our findings may enable to improve bulk and edge properties of topological insulators based on InAs/GaSb quantum well heterostructures solely by means of an electric field rather than temperature which opens the paths towards their application for macroscopic devices.

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Optical tuning of the charge carrier type in the topological regime of InAs/GaSb quantum wells

Cited by 8 publications

References 39 publications

p‐Type Doped AlAsSb/GaSb Resonant Tunneling Diode Photodetector for the Mid‐Infrared Spectral Region

p‐Type Doped AlAsSb/GaSb Resonant Tunneling Diode Photodetector for the Mid‐Infrared Spectral Region

Optical response of an inverted InAs/GaSb quantum well in an in-plane magnetic field*

Voltage control of the quantum scattering time in InAs/GaSb/InAs trilayer quantum wells

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