TITLE

Pulsed terahertz time domain spectroscopy of vertically structured photoconductive antennas

AUTHOR(S)
Faulks, R.; Rihani, S.; Beere, H. E.; Evans, M. J.; Ritchie, D. A.; Pepper, M.
PUB. DATE
February 2010
SOURCE
Applied Physics Letters;Feb2010, Vol. 96 Issue 8, p081106
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We present a terahertz (THz) photoconductive emitter structure, which employs a n-doped layer underneath a low-temperature-grown GaAs region to enable the THz transient to couple vertically through a defined mesa. A nonlinear bias dependence is observed, yielding an order in magnitude improvement in power for a mesa device with a 100 μm2 area over a conventional planar control reference device at 32 V and 5 mW illumination power. We relate the bias dependence of the THz signal to the breakdown voltage observed in the current-voltage characteristic. Reducing the antenna gap size through reducing the thickness of the low temperature-GaAs region below 1 μm shows a large improvement in the bandwidth of the device, with an enhancement of the normalized intensity between 0.2 to 2 THz for a bow-tie antenna geometry.
ACCESSION #
48352181

 

Related Articles

  • Structure investigation of low-temperature-grown GaAsSb, a material for photoconductive terahertz antennas. Sigmund, J.; Sydlo, C.; Hartnagel, H. L.; Benker, N.; Fuess, H.; Rutz, F.; Kleine-Ostmann, T.; Koch, M. // Applied Physics Letters;12/19/2005, Vol. 87 Issue 25, p252103 

    The formation of precipitates after an annealing process in low-temperature-grown GaAs0.6Sb0.4 is observed. We use high-resolution transmission electron microscopy for a detailed structure investigation and demonstrate the functionality of the material, which has a band gap of 0.86 eV, for...

  • Photoconductivity in confined gallium. Fedotov, V. A.; Woodford, M.; Jean, I.; Zheludev, N. I. // Applied Physics Letters;2/18/2002, Vol. 80 Issue 7, p1297 

    We report on the observation of photoconductivity in elemental gallium confined at an interface with glass. The effect is associated with a fully reversible light-induced structural transformation in the metal, which affects a surface layer only a few nanometers thick. The effect has the...

  • Polarity replication across m-plane GaN/ZnO interfaces. Kobayashi, Atsushi; Ohnishi, Tsuyoshi; Lippmaa, Mikk; Oda, Yasuhiro; Ishii, Akira; Ohta, Jitsuo; Oshima, Masaharu; Fujioka, Hiroshi // Applied Physics Letters;10/31/2011, Vol. 99 Issue 18, p181910 

    We have investigated the crystal plane alignment at m-plane GaN/ZnO heterointerfaces prepared by a room temperature epitaxial growth technique. Coaxial impact-collision ion scattering spectroscopy was used to show that the +c directions for GaN and ZnO are aligned at the GaN/ZnO ([formula])...

  • Gallium implantation induced deep levels in n-type 6H-SIC. Gong, M.; Fung, S. // Journal of Applied Physics;1/1/1999, Vol. 85 Issue 1, p105 

    Presents information on a study which observed two gallium-acceptor levels in the Ga-implanted p+n diodes using deep level transient spectroscopy. Experimental procedure; Results and discussion; Conclusion.

  • Effect of Ga content on defect states in CuIn1-xGaxSe2 photovoltaic devices. Heath, J. T.; Cohen, J. D.; Shafarman, W. N.; Liao, D. X.; Rockett, A. A. // Applied Physics Letters;6/17/2002, Vol. 80 Issue 24, p4540 

    Defects in the band gap of Culn[sub 1-χGa[sub χ]Se[sub 2] have been characterized using transient photocapacitance spectroscopy. The measured spectra clearly show response from a band of defects centered around 0.8 eV from the valence band edge as well as an exponential distribution of...

  • Optical antenna: Towards a unity efficiency near-field optical probe. Grober, Robert D.; Schoelkopf, Robert J. // Applied Physics Letters;3/17/1997, Vol. 70 Issue 11, p1354 

    Demonstrates the use of an antenna to realize a near-field optical probe that combines spatial resolution well below the diffraction limit with transmission efficiency approaching unity. Components of the probe; Advances of the antennae and the electric dipole aspects over the traditional...

  • Generation of terahertz radiation using zinc oxide as photoconductive material excited by ultraviolet pulses. Ono, Shingo; Murakami, Hidetoshi; Quema, Alex; Diwa, Gilbert; Sarukura, Nobuhiko; Nagasaka, Ryujiro; Ichikawa, Yo; Ogino, Hiraku; Ohshima, Eriko; Yoshikawa, Akira; Fukuda, Tsuguo // Applied Physics Letters;12/26/2005, Vol. 87 Issue 26, p261112 

    Terahertz (THz) radiation generated from photoconductive antenna fabricated on a single crystal zinc oxide (ZnO) is presented. The THz-radiation power is saturated at bias voltages above 800 V/cm and the obtained spectrum extends up to 1 THz. Moreover, ZnO is found to be highly transparent in...

  • Competition between electronic and vibrational predissociation dynamics of the HeBr2 and NeBr2 van der Waals molecules. Taylor, Molly A.; Pio, Jordan M.; van der Veer, Wytze E.; Janda, Kenneth C. // Journal of Chemical Physics;3/14/2010, Vol. 132 Issue 10, p104309 

    Direct measurements of the lifetimes of He79Br2 and Ne79Br2 B-state vibrational levels 10≤ν′≤20 have been performed using time-resolved optical pump-probe spectroscopy. The values do not obey the energy gap law for direct vibrational predissociation. For both molecules, the...

  • The effect of photon energy and temperature on the persistent tunneling photoconductivity effect in Al/δ(Si)-GaAs structures. Kotel’nikov, I.N.; Dizhur, S.E.; Feiginov, M.N.; Mordovets, N.A. // Semiconductors;Jul2006, Vol. 40 Issue 7, p818 

    The phenomenon of persistent tunneling photoconductivity was studied using the tunneling spectroscopy technique at liquid-helium temperature: the separation between the unoccupied levels in a δ-doped layer at the GaAs surface decreased after illumination. This decrease was due to an increase...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics