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- Balocco, C, et al.
(författare)
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Microwave detection at 110 GHz by nanowires with broken symmetry
- 2005
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 5:7, s. 1423-1427
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Tidskriftsartikel (refereegranskat)abstract
- By using arrays of nanowires with intentionally broken symmetry, we were able to detect microwaves up to 110 GHz at room temperature. This is, to the best of our knowledge, the highest speed that has been demonstrated in different types of novel electronic nanostructures to date. Our experiments showed a rather stable detection sensitivity over a broad frequency range from 100 MHz to 110 GHz. The novel working principle enabled the nanowires to detect microwaves efficiently without a dc bias. In principle, the need for only one high-resolution lithography step and the planar architecture allow an arbitrary number of nanowires to be made by folding a linear array as many times as required over a large area, for example, a whole wafer. Our experiment on 18 parallel nanowires showed a sensitivity of approximately 75 mV dc output/mW of nominal input power of the 110 GHz signal, even though only about 0.4% of the rf power was effectively applied to the structure because of an impedance mismatch. Because this array of nanowires operates simultaneously, low detection noise was achieved, allowing us to detect -25 dBm 110 GHz microwaves at zero bias with a standard setup.
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| 2. |
- Song, AM, et al.
(författare)
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Diode-like characteristics of nanometer-scale semiconductor channels with a broken symmetry
- 2004
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Ingår i: Proceedings of the Eleventh International Conference on Modulated Semiconductor Structures (Physica E: Low-dimensional Systems and Nanostructures). - : Elsevier BV. - 1386-9477. ; 21:2-4, s. 1116-1120
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Konferensbidrag (refereegranskat)abstract
- We present a new type of nanometer-scale semiconductor nonlinear device, called self-switching device (SSD). The device was realized by simply etching insulating grooves into a semiconductor, between which a narrow channel with a broken symmetry was formed. Because of the asymmetry in the channel boundary, an applied voltage V not only changes the potential profile along the channel direction, but also either widens or narrows the effective channel width depending on the sign of V. This results in a diode-like current-voltage characteristic but without the use of any doping junction or barrier structure. The turn-on voltage can also be widely tuned from virtually 0 to more than 10 V by simply adjusting the channel width. Furthermore, only one lithography step was needed to fabricate SSDs. We used two different material systems, InGaAs-InP and InGaAs-InAlAs, to realize SSDs and the results at room temperature were compared. We also show that by adding a third terminal to an SSD as a gate, the turn-on voltage of the device could be tuned by the gate bias and the device functions either as a tunable diode or as a transistor. (C) 2003 Elsevier B.V. All rights reserved.
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