Theoretical and experimental investigations of subpicosecond photoconductivity

Monte Carlo methods are used to study photoconductive transients in gallium arsenide. It is demonstrated that working with presently established ranges for the Γ‐L coupling coefficient, the existence of a velocity overshoot at moderate fields cannot be exactly predicted. The role of negative velocity electrons in the initial transient for short wavelength excitation is also demonstrated. Details of an actual experiment are described and evaluated against a model which incorporates the Monte Carlo simulation into a transmission line structure with a frequency‐dependent characteristic impedance. The results demonstrate that an appropriately designed experiment can observe subpicosecond carrier transport transients.

[1]  H. Cox,et al.  Dispersion of the saturated current in GaAs from dc to 1200 GHz , 1983 .

[2]  R. Grondin,et al.  Transport correlation coefficients and photoconductive switching , 1988 .

[3]  W. Shockley.  Currents to Conductors Induced by a Moving Point Charge , 1938 .

[4]  D. E. Aspnes,et al.  GaAs lower conduction-band minima: Ordering and properties , 1976 .

[5]  J. Wilkins,et al.  Small‐signal ac conductivity and velocity overshoot in semiconductor materials , 1982 .

[6]  W. Wiegmann,et al.  Hot electron spectroscopy , 1984 .

[7]  A. E. Iverson,et al.  Overshoot in the response of a photoconductor excited by subpicosecond pulses , 1988 .

[8]  Jeffrey Frey,et al.  Electron velocity in Si and GaAs at very high electric fields , 1980 .

[9]  Gerard Mourou,et al.  Picosecond Electronics and Optoelectronics , 1989 .

[10]  Gerard Mourou,et al.  Propagation model for ultrafast signals on superconducting dispersive striplines , 1988 .

[11]  D. Kleinman,et al.  Cerenkov Radiation from Femtosecond Optical Pulses in Electro-Optic Media , 1984, Topical Meeting on Ultrafast Phenomena.

[12]  P. Lugli,et al.  Transient hot-phonon effects on the velocity overshoot of GaAs: a Monte Carlo analysis , 1988 .

[13]  J. G. Ruch,et al.  Electron dynamics in short channel field-effect transistors , 1972 .

[14]  T. H. Windhorn,et al.  High field temperature dependent electron drift velocities in GaAs , 1982 .

[15]  Karl Hess,et al.  Theory of high-field transport of holes in GaAs and InP , 1984 .

[16]  M. Heiblum,et al.  dc performance of ballistic tunneling hot‐electron transfer amplifiers , 1986 .

[17]  R. Hammond.  Electron velocity overshoot observed in an impulse-excited GaAs photoconductor , 1985 .

[18]  S. Ramo.  Currents Induced by Electron Motion , 1939, Proceedings of the IRE.

[19]  R. A. Logan,et al.  Picosecond nonequilibrium carrier transport in GaAs , 1981 .

[20]  Gerard Mourou,et al.  Subpicosecond photoconductivity overshoot in gallium arsenide observed by electro‐optic sampling , 1988 .

[21]  E. Kane,et al.  Band structure of indium antimonide , 1957 .

[22]  Capasso,et al.  Direct subpicosecond measurement of carrier mobility of photoexcited electrons in gallium arsenide. , 1987, Physical review letters.

[23]  D. Auston,et al.  Impulse response of photoconductors in transmission lines , 1983 .

[24]  David J. Erskine,et al.  Ultrafast relaxation dynamics of photoexcited carriers in GaAs and related compounds , 1985 .

[25]  Mohamed A. Osman,et al.  Electron‐hole interaction and high‐field transport of photoexcited electrons in GaAs , 1987 .

[26]  Mohamed A. Osman,et al.  Monte Carlo investigation of the electron-hole-interaction effects on the ultrafast relaxation of hot photoexcited carriers in GaAs. , 1987 .

[27]  H D Rees,et al.  A reappraisal of instabilities due to the transferred electron effect , 1973 .

[28]  P. Kocevar,et al.  Electronic power transfer in pulsed laser excitation of polar semiconductors , 1983 .

[29]  Gerard Mourou,et al.  Subpicosecond electrical sampling , 1983 .

[30]  David J. Jones,et al.  Electron-relaxation effects in transferred-electron devices revealed by new simulation method , 1972 .

[31]  G. Bernstein,et al.  Fabrication of ultra-short gate MESFETs and BlochFETS by electron beam lithography , 1986 .

[32]  J. East,et al.  Effects of transient carrier transport in millimeter-wave GaAs diodes , 1984, IEEE Transactions on Electron Devices.

[33]  H. Grubin,et al.  CARRIER-CARRIER INTERACTION AND INTERVALLEY TRANSFER EFFECTS ON THE ULTRAFAST RELAXATION OF PHOTOEXCITED ELECTRONS IN GaAs , 1988 .

[34]  H. Rees.  Time response of the high-field electron distribution function in GaAs , 1969 .

[35]  Tsang,et al.  Determination of intervalley scattering rates in GaAs by subpicosecond luminescence spectroscopy. , 1987, Physical review letters.