1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Terahertz current oscillations in a gated two-dimensional electron gas with antenna integrated at the channel ends
Rent:
Rent this article for
USD
10.1063/1.4717464
/content/aip/journal/apl/100/20/10.1063/1.4717464
http://aip.metastore.ingenta.com/content/aip/journal/apl/100/20/10.1063/1.4717464
View: Figures

Figures

Image of FIG. 1.
FIG. 1.

(a) Schematics of the epitaxial layers forming the heterostructure together with fabricated ohmic and gate contacts. Two 2DEGs are present in the active InGaAs layer sandwiched between two AlGaAs barriers, and their charge density is modulated the Ti/Au gate electrode evaporated on top of the upper barrier layer. (b) SEM image of the HFET layout with the integrated bow-tie antenna connected to the ends of the transistor channel (source and drain contacts). The arrow indicates the polarization direction of the electric field of the radiation. (c) Transfer characteristics of the HFET. Channel conductance (blue thin line) and mutual transconductance (red thick line) were calculated from the drain current measured in dc with a drain-source voltage of 300 mV.

Image of FIG. 2.
FIG. 2.

(a)–(f) Optical responsivity spectra of the lens-coupled HFET detector calculated from the lock-in signal at the drain port for different values of the dc gate voltage Vg . Data are normalized by the frequency-dependent input radiation power emitted in free-space by a tunable THz source in two available frequency ranges. Note the change of sign in panel (b) due to the crossover between two different detection mechanisms. Inset of panel (a): schematic section of the detector package with Si substrate lens and front-end optics (off-axis parabolic mirror (OPA)). The radiation was linearly polarized along the bow-tie axis so that a THz-oscillating electric field is established along the channel. Inset of panel (d): instantaneous electric field map in the vicinity of the channel calculated in a simplified scheme with an electromagnetic solver (CST microwave studio). A THz-oscillating potential is produced between source and gate and between gate and drain.

Image of FIG. 3.
FIG. 3.

(a),(b) Comparison between experimental responsivity (red circles) at 183 GHz and 255 GHz and that one calculated from dc transport data (blue line) following Eqs. (2) and (3), respectively. Insets: examples of the instantaneous channel potential under the gate U(x) in the case of impedance matching (a) and severe mismatch (b) (full and dashed lines correspond to opposite phases of the oscillation). (c) Root-mean-square detector noise at 1 kHz within 1 Hz bandwidth.

Loading

Article metrics loading...

/content/aip/journal/apl/100/20/10.1063/1.4717464
2012-05-14
2014-04-20
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Terahertz current oscillations in a gated two-dimensional electron gas with antenna integrated at the channel ends
http://aip.metastore.ingenta.com/content/aip/journal/apl/100/20/10.1063/1.4717464
10.1063/1.4717464
SEARCH_EXPAND_ITEM