Influence of a Strong Electric Field on the Carrier Capture by Nonradiative Deep‐Level Centers in GaAs

Abstract

The techniques of capacitance spectroscopy are used to measure directly electron and hole capture cross-sections of deep levels in a neutral material at zero electric field and in the depletion layer with a strong electric field. The data show that if at zero electric field the electron capture crosssections onto the centers are thermally activated and described by the theory of nonradiative multiphonon capture, then in a strong electric field (P z lo4 V/cm) the capture cross-sections increase to the limiting large value (a Y lOV14 to 10-12 cmz) and are only little dependent on temperature. It is shown that an electric field causes a simultaneous increase of the electron and hole capture cross-sections of the level EL2 by five orders of magnitude at low temperatures (27 Y Y 90 K).

An extended drift-diffusion model of semi-insulating n-GaAs Schottky-barrier diodes

“…This mechanism is found to be at the basis of the electrical behaviour of this device by controlling the nearly saturated value of the electric field at the Schottky barrier and thus originating the extension of the depletion region at increasing bias. The evidence of the influence of electric field on the carrier capture by deep traps in GaAs has been qualitatively substantiated by other authors [26][27][28][29]. However, in view of the recent data of [17] the quantitative field dependence of the capture cross-section still remains an intriguing problem which needs further investigation.…”

Analysis of uniformity of as prepared and irradiated SI GaAs radiation detectors

“…There are some indications that the electron and the hole capture cross section of some deep trapping centres, (Ec-0.76 eV) for electrons and (E,+0.56 eV) for holes, increases with increasing electric field [23].…”

A study of the electric field transient at the Au/semi-insulating GaAs contact under an alternating current square-pulse bias

“…The constancy of the electric field has been attributed to the enhancement of the electron capture cross-section of the deep donor EL2 [9][10][11]. Direct observation of enhancement of the EL2 capture cross-section at high electric field (∼10 kV cm −1 ) was reported by Prints and Parsey [12], and by Prinz and Rechkunov [13]. As the electron-phonon coupling of EL2 is strong, there is a large Frank-Condon shift in the ionization process EL2 0 → EL2 + .…”