| 1. |
- Borg, Mattias, et al.
(författare)
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InAs/GaSb Heterostructure Nanowires for Tunnel Field-Effect Transistors.
- 2010
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 10:Online August 24, 2010, s. 4080-4085
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Tidskriftsartikel (refereegranskat)abstract
- InAs/GaSb nanowire heterostructures with thin GaInAs inserts were grown by MOVPE and characterized by electrical measurements and transmission electron microscopy. Down-scaling of the insert thickness was limited because of an observed sensitivity of GaSb nanowire growth to the presence of In. By employing growth interrupts in between the InAs and GaInAs growth steps it was possible to reach an insert thickness down to 25 nm. Two-terminal devices show a diode behavior, where temperature-dependent measurements indicate a heterostructure barrier height of 0.5 eV, which is identified as the valence band offset between the InAs and GaSb. Three-terminal transistor structures with a top-gate positioned at the heterointerface show clear indications of band-to-band tunnelling.
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| 2. |
- Dey, Anil, et al.
(författare)
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High Current Density InAsSb/GaSb Tunnel Field Effect Transistors
- 2012
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Ingår i: Device research conference. - 1548-3770. ; , s. 205-206
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Konferensbidrag (refereegranskat)abstract
- Steep-slope devices, such as tunnel field-effect transistors (TFETs), have recently gained interest due to their potential for low power operation at room temperature. The devices are based on inter-band tunneling which could limit the on-current since the charge carriers must tunnel through a barrier to traverse the device. The InAs/GaSb heterostructure forms a broken type II band alignment which enables inter-band tunneling without a barrier, allowing high on-currents. We have recently demonstrated high current density (Ion,reverse = 17.5 mA/µm) nanowire Esaki diodes and in this work we investigate the potential of InAs/GaSb heterostructure nanowires to operate as TFETs. We present device characterization of InAs 0.85 Sb 0.15 /GaSb nanowire TFETs, which exhibit record-high on-current levels.
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| 3. |
- Dey, Anil, et al.
(författare)
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High-Current GaSb/InAs(Sb) Nanowire Tunnel Field-Effect Transistors
- 2013
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 34:2, s. 211-213
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Tidskriftsartikel (refereegranskat)abstract
- We present electrical characterization of GaSb/InAs(Sb) nanowire tunnel field-effect transistors. The broken band alignment of the GaSb/InAs(Sb) heterostructure is exploited to allow for interband tunneling without a barrier, leading to high ON-current levels. We report a maximum drive current of 310 μA/μm at Vds = 0.5 V. Devices with scaled gate oxides display transconductances up to gm = 250 mS/mm at Vds = 300 mV, which are normalized to the nanowire circumference at the axial heterojunction.
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| 4. |
- Ganjipour, Bahram, et al.
(författare)
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Carrier control and transport modulation in GaSb/InAsSb core/shell nanowires
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 101:10
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Tidskriftsartikel (refereegranskat)abstract
- We report transport studies of GaSb/InAs core/shell nanowires. It is shown that with increasing InAs shell thickness, it is possible to tune the carrier concentrations and transport in the structures from p-type (core-dominated) to n-type (shell dominated). For nanowires with an intermediate shell thickness (5-7 nm), we show that the transport is ambipolar, such that an applied top-gate potential can provide further control of carrier type and transport path. In this range, the nature of the GaSb-InAs junction also changes from broken gap (semimetal) to staggered (narrow bandgap) with a small decrease in shell thickness. From a device point of view, we demonstrate that the presence of a thin (<3 nm) InAs shell improves p-type GaSb nanowire transistor characteristics. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4749283]
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| 5. |
- Ganjipour, Bahram, et al.
(författare)
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Electrical properties of GaSb/InAsSb core/shell nanowires
- 2014
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 25:42
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Tidskriftsartikel (refereegranskat)abstract
- Temperature dependent electronic properties of GaSb/InAsSb core/shell and GaSb nanowires have been studied. Results from two-probe and four-probe measurements are compared to distinguish between extrinsic (contact-related) and intrinsic (nanowire) properties. It is found that a thin (2-3 nm) InAsSb shell allows low barrier charge carrier injection to the GaSb core, and that the presence of the shell also improves intrinsic nanowire mobility and conductance in comparison to bare GaSb nanowires. Maximum intrinsic field effect mobilities of 200 and 42 cm(2) Vs(-1) were extracted for the GaSb/InAsSb core/shell and bare-GaSb NWs at room temperature, respectively. The temperature-dependence of the mobility suggests that ionized impurity scattering is the dominant scattering mechanism in bare GaSb while phonon scattering dominates in core/shell nanowires. Top-gated field effect transistors were fabricated based on radial GaSb/InAsSb heterostructure nanowires with shell thicknesses in the range 5-7 nm. The fabricated devices exhibited ambipolar conduction, where the output current was studied as a function of AC gate voltage and frequency. Frequency doubling was experimentally demonstrated up to 20 kHz. The maximum operating frequency was limited by parasitic capacitance associated with the measurement chip geometry.
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| 6. |
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| 7. |
- Ganjipour, Bahram, et al.
(författare)
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GaSb nanowire single-hole transistor
- 2011
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 99:26
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Tidskriftsartikel (refereegranskat)abstract
- We present an experimental study of single hole transistors (SHTs) made from p-type GaSb nanowires. Closely spaced source-drain electrodes are fabricated onto GaSb nanowires to define a SHT within a GaSb nanowire. Room temperature back-gate transfer characteristics show typical hole transport behavior. The fabricated devices are characterized by transport measurements at 1.5 K, where periodic conductance oscillations due to Coulomb blockade are observed and a charging energy of 5 meV is determined. (C) 2011 American Institute of Physics. [doi:10.1063/1.3673328]
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| 8. |
- Ganjipour, Bahram, et al.
(författare)
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High current density Esaki tunnel diodes based on GaSb-InAsSb heterostructure nanowires
- 2011
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 11:10, s. 4222-4226
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Tidskriftsartikel (refereegranskat)abstract
- We present electrical characterization of broken gap GaSb-InAsSb nanowire heterojunctions. Esaki diode characteristics with maximum reverse current of 1750 kA/cm2 at 0.50 V, maximum peak current of 67 kA/cm2 at 0.11 V, and peak-to-valley ratio (PVR) of 2.1 are obtained at room temperature. The reverse current density is comparable to that of state-of-the-art tunnel diodes based on heavily doped p-n junctions. However, the GaSb-InAsSb diodes investigated in this work do not rely on heavy doping, which permits studies of transport mechanisms in simple transistor structures processed with high-κ gate dielectrics and top-gates. Such processing results in devices with improved PVR (3.5) and stability of the electrical properties.
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| 9. |
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| 10. |
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