Regensburg 2000 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 38: Poster III: Transporteigenschaften (1-14), Optische Eigenschaften (15-31), Grenz-/Oberfl
ächen (32-44), Heterostrukturen (45-57), Bauelemente (58-67), Gitterdynamik (68-69), Diamant (70), Raster-Tunnel-Mikroskopie (71)

HL 38.17: Poster

Donnerstag, 30. März 2000, 14:00–19:00, B

Near-zone field enhanced ponderomotive action of FIR laser radiation on the tunnel current through a Schottky barrier — •E. Zepezauer¹, A. Ya. Shul’man², S. D. Ganichev^1,3, I. N. Kotel’nikov², E. M. Dizhur⁴, A. B. Ormont², Yu. V. Fedorov², and W. Prettl¹ — ¹Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, Germany — ²Institute for Radioengineering and Electronics, RAS, Moscow, Russia — ³A. F. Ioffe Physicotechnical Institute, RAS, St. Petersburg, Russia — ⁴Institute for High Pressure Physics, RAS, Troitsk, Russia

Far infrared (FIR) high-power pulsed laser radiation incident normal to the surface of GaAs/metal heterostructures with a self-consistent tunnel Schottky barrier gives rise to a change in the tunnel conductance. We show that the observed photoresistive effects are caused by ponderomotive forces of the radiation field on the free electron plasma in the junctions. At low power levels the change of the tunnel conductance rises linearly with increasing intensity, and proceeds into a strongly superlinear dependence at high intensities. It is shown that this superlinearity is a result of an enhancement of the local radiation field in the near-zone of diffraction by inhomogeneities at the metal-semiconductor interface and depends strongly on the surface roughness of the metal electrode. Furthermore the experimental results are compared to a nonlinear extension of the theory of electron redistribution due to the radiation pressure.[1]

[1] A. Ya. Shul’man et.al.; phys. stat. sol. (a) 175, 289 (1999)