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Mechanism of Radiation Coupling to Plasma Wave Field Effect Transistor Sub-THz Detectors

100%

Sakowicz M., Łusakowski J., Karpierz K., Grynberg M., Gwarek W., Knap W., Boubanga S.

Acta Physica Polonica A

2008

vol. 114

issue 5

1337-1342

Detection of 100 GHz and 285 GHz electromagnetic radiation by GaAs/AlGaAs field effect transistors with the gate length of 150 nm was investigated at 300 K as a function of the angleαbetween the direction of linear polarization of the radiation and the symmetry axis of the field effect transistors. The angular dependence of the detected signal was found to be Acos²(α-α₀)+C. A response of the transistor chip (including bonding wires and the substrate) to the radiation was numerically simulated. Calculations confirmed experimentally observed dependences and allowed to investigate the role of bonding wires and contact pads in coupling of the radiation to the transistor channel.

Spectroscopy of Be Acceptor Ground State in GaAs/AlGaAs Heterostructure

100%

Łusakowski J., Buczko R., Sakowicz M., Friedland K., Hey R., Ploog K.

Acta Physica Polonica A

2007

vol. 112

issue 2

209-213

Photoluminescence measurements were carried out on Be δ-doped GaAs/Al_{0.33}Ga_{0.67}As heterostructure at 1.6 K in magnetic fields (B) up to 4 T. Luminescence originating from recombination of a two-dimensional electron gas and photoexcited holes localized on Be acceptors was analyzed. The degree of circular polarization (γ_C) of the luminescence from fully occupied Landau levels was determined as a function of B and the two-dimensional electron gas concentration, n_s. At B constant,γ_C decreased with the increase in n_s. The intensity of the optical transition considered was calculated with taking into account s- and d-like parts of the acceptor envelope function. It is shown that the presence of the d-like part explains the observed γ_C(n_s) dependence quantitatively. This shows that polarization spectroscopy on acceptorδ-doped heterostructures enables one to test experimentally the contribution of the L>0 component of the envelope in a shallow acceptor description.

Terahertz Detection by the Entire Channel of High Electron Mobility Transistors

68%

Sakowicz M., Łusakowski J., Karpierz K., Knap W., Grynberg M., Köhler K., Valusis G., Gołaszewska K., Kamińska E., Piotrowska A., Caban P., Strupiński W.

Acta Physica Polonica A

2008

vol. 114

issue 5

1343-1348

GaAs/AlGaAs and GaN/AlGaN high electron mobility transistors were used as detectors of THz electromagnetic radiation at liquid helium temperatures. Application of high magnetic fields led to the Shubnikov-de Haas oscillations of the detection signal. Measurements carried out with a simultaneous modulation of the intensity of the incident THz beam and the transistor gate voltage showed that the detection signal is determined by the electron plasma both in the gated and ungated parts of the transistor channel. This result is of importance for understanding the physical mechanism of the detection in high electron mobility transistors and for development of a proper theoretical description of this process.

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3 Acta Physica Polonica A

2 2008

1 2007

3 Sakowicz M.

3 Łusakowski J.

2 Grynberg M.

2 Karpierz K.

2 Knap W.

1 Boubanga S.

1 Buczko R.

1 Caban P.

1 Friedland K.

1 Gołaszewska K.

1 Gwarek W.

1 Hey R.

1 Kamińska E.

1 Köhler K.

1 Piotrowska A.

1 Ploog K.

1 Strupiński W.

1 Valusis G.

Search results

Mechanism of Radiation Coupling to Plasma Wave Field Effect Transistor Sub-THz Detectors

Spectroscopy of Be Acceptor Ground State in GaAs/AlGaAs Heterostructure

Terahertz Detection by the Entire Channel of High Electron Mobility Transistors