Ultrafast Phenomena in Freestanding LT-GaAs Devices

M. Marsoa, M. Mikulicsa,b, R. Adama, S. Wuc, X. Zhengc, I. Camarab, F. Siebeb, A. Förstera, R. Güstenb, P. Kordoša and R. Sobolewskic aInstitute of Thin Films and Interfaces, Research Center Jülich, 52425 Jülich, Germany bMax-Planck-Institut für Radioastronomie, 53121 Bonn, Germany cDepartment of Electrical and Computer Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627-0231, USA

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Received: 22 08 2004;

We report on the fabrication and high-frequency performance of our photodetectors and photomixers based on freestanding low-temperature-grown GaAs. The MBE-grown low-temperature GaAs layers are lifted from the native GaAs substrate and transferred on top of variety of host substrates. The freestanding devices exhibit breakdown electrical fields above 200 kV/cm and dark currents below 3×10-7 A at 100 V bias. Device photoresponse shows 0.55 ps wide electrical transients with voltage amplitudes up to 1.3 V, measured using an electro-optical sampling technique with 100 fs wide laser pulses. Photomixing experiments at 460 GHz yield a 9 times higher output power for the freestanding device on Si/SiO2 host substrate compared to the native substrate.

DOI: 10.12693/APhysPolA.107.109 PACS numbers:72.20.Jv, 72.40.+w, 78.30.Fs, 85.60.-q, 85.60.Gz