| 291. |
- Svensson, Johannes, et al.
(författare)
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Diameter-Dependent Photocurrent in InAsSb Nanowire Infrared Photodetectors.
- 2013
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 13:4, s. 1380-1385
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Tidskriftsartikel (refereegranskat)abstract
- Photoconductors using vertical arrays of InAs/InAs1-xSbx nanowires with varying Sb composition x have been fabricated and characterized. The spectrally resolved photocurrents are strongly diameter dependent with peaks, which are red-shifted with diameter, appearing for thicker wires. Results from numerical simulations are in good agreement with the experimental data and reveal that the peaks are due to resonant modes that enhance the coupling of light into the wires. Through proper selection of wire diameter, the absorptance can be increased by more than 1 order of magnitude at a specific wavelength compared to a thin planar film with the same amount of material. A maximum 20% cutoff wavelength of 5.7 μm is obtained at 5 K for a wire diameter of 717 nm at a Sb content of x = 0.62, but simulations predict that detection at longer wavelengths can be achieved by increasing the diameter. Furthermore, photodetection in InAsSb nanowire arrays integrated on Si substrates is also demonstrated.
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| 292. |
- Svensson, Johannes, et al.
(författare)
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III-V Nanowire Complementary Metal-Oxide Semiconductor Transistors Monolithically Integrated on Si
- 2015
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 15:12, s. 7898-7904
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Tidskriftsartikel (refereegranskat)abstract
- III-V semiconductors have attractive transport properties suitable for low-power, high-speed complementary metal oxide-semiconductor (CMOS) implementation, but major challenges related to cointegration of III-V n- and p-type metal-oxide-semiconductor field-effect transistors (MOSFETs) on low-cost Si substrates have so far hindered their use for large scale logic circuits. By using a novel approach to grow both InAs and InAs/GaSb vertical nanowires of equal length simultaneously in one single growth step, we here demonstrate n- and p-type III-V MOSFETs monolithically integrated on a Si substrate with high I-on/I-off ratios using a dual channel, single gate-stack design processed simultaneously for both types of transistors. In addition, we demonstrate fundamental CMOS logic gates, such as inverters and NAND gates, which illustrate the viability of our approach for large scale III-V MOSFET circuits on Si.
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| 293. |
- Thompson, Michael D, et al.
(författare)
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Low Leakage-Current InAsSb Nanowire Photodetectors on Silicon.
- 2016
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 16:1, s. 182-187
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Tidskriftsartikel (refereegranskat)abstract
- Axially doped p-i-n InAs0.93Sb0.07 nanowire arrays have been grown on Si substrates and fabricated into photodetectors for shortwave infrared detection. The devices exhibit a leakage current density around 2 mA/cm(2) and a 20% cutoff of 2.3 μm at 300 K. This record low leakage current density for InAsSb based devices demonstrates the suitability of nanowires for the integration of III-V semiconductors with silicon technology.
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| 294. |
- Timm, Rainer, et al.
(författare)
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Interface composition of InAs nanowires with Al2O2 and HfO2 thin films
- 2011
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 99:22, s. 1-222907
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedVertical InAs nanowires (NWs) wrapped by a thin high-kappa dielectric layer may be a key to the next generation of high-speed metal-oxide-semiconductor devices. Here, we have investigated the structure and chemical composition of the interface between InAs NWs and 2 nm thick Al(2)O(3) and HfO(2) films. The native oxide on the NWs is significantly reduced upon high-kappa deposition, although less effective than for corresponding planar samples, resulting in a 0.8 nm thick interface layer with an In-/As-oxide composition of about 0.7/0.3. The exact oxide reduction and composition including As-suboxides and the role of the NW geometry are discussed in detail.
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| 295. |
- Troian, Andrea, et al.
(författare)
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InAs-oxide interface composition and stability upon thermal oxidation and high-k atomic layer deposition
- 2018
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Defects at the interface between InAs and a native or high permittivity oxide layer are one of the main challenges for realizing III-V semiconductor based metal oxide semiconductor structures with superior device performance. Here we passivate the InAs(100) substrate by removing the native oxide via annealing in ultra-high vacuum (UHV) under a flux of atomic hydrogen and growing a stoichiometry controlled oxide (thermal oxide) in UHV, prior to atomic layer deposition (ALD) of an Al2O3 high-k layer. The semiconductor-oxide interfacial stoichiometry and surface morphology are investigated by synchrotron based X-ray photoemission spectroscopy, scanning tunneling microscopy, and low energy electron diffraction. After thermal oxide growth, we find a thin non-crystalline layer with a flat surface structure. Importantly, the InAs-oxide interface shows a significantly decreased amount of In3+, As5+, and As0 components, which can be correlated to electrically detrimental defects. Capacitance-voltage measurements confirm a decrease of the interface trap density in gate stacks including the thermal oxide as compared to reference samples. This makes the concept of a thermal oxide layer prior to ALD promising for improving device performance if this thermal oxide layer can be stabilized upon exposure to ambient air.
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| 296. |
- Wallentin, Jesper, et al.
(författare)
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Hard X-ray Detection Using a Single nm Diameter Nanowire
- 2014
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 14:12, s. 7071-7076
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Tidskriftsartikel (refereegranskat)abstract
- Submicron sized sensors could allow higher resolution in X-ray imaging and diffraction measurements, which are ubiquitous for materials science and medicine. We present electrical measurements of a single 100 nm diameter InP nanowire transistor exposed to hard X-rays. The X-ray induced conductance is over 5 orders of magnitude larger than expected from reported data for X-ray absorption and carrier lifetimes. Time-resolved measurements show very long characteristic lifetimes on the order of seconds, tentatively attributed to long-lived traps, which give a strong amplification effect. As a proof of concept, we use the nanowire to directly image an X-ray nanofocus with submicron resolution.
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| 297. |
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| 298. |
- Wernersson, Lars-Erik
(författare)
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Electron microscopy studies of nanowires
- 2007
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Ingår i: Book of abstracts: Aminoff Symp: Carbon nanotubes - with an eye on the nanoworld, Stockholm, Sweden (2007), invited.
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Konferensbidrag (refereegranskat)
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| 299. |
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| 300. |
- Wernersson, Lars-Erik
(författare)
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High-performance InAs NW MISFETs
- 2007
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Ingår i: Book of abstracts: 8th Sweden-Japan Intl Workshop on Quantum Nanoelectronics, Lund, Sweden (2007), invited.
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Konferensbidrag (refereegranskat)
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