QUENCHING OF PERSISTENT PHOTOCONDUCTIVITY AND DECREASE OF ELECTRON-CONCENTRATION BY HIGH ELECTRIC-FIELDS IN GAAS DELTA-DOPED BY SN ON VICINAL SUBSTRATE STRUCTURES

This paper reports the measurements of high electric field transport a nd the persistent photoconductivity in delta-doped by Sn on vicinal an d singular substrate GaAs structures. Transport properties of the hot electron gas were measured in the temperature range 4.2 K < T < 300 K at high electric fields up to E = 10(4) V/cm in darkness and under ill umination using a pulse technique. Dependence of the current density J (E) showed an anisotropy in [110] and [(1) over bar 10] directions in GaAs(delta-Sn) on vicinal substrate structures and histeresis in elect ric field at low temperatures. In GaAs(delta-Sn) on singular substrate structures the anisotropy of conductivity is small. The persistent ph otoconductivity was observed with well defined threshold T-c approxima te to 240 K in GaAs(delta-Sn) on vicinal substrate structures. At T = 4.2 K by applying a high voltage the persistent photoconductivity may be quenched and the resistance of the sample increased by an order of magnitude. The high conductivity state arises again due to illuminatio n of the sample or due to heating to temperatures above approximate to 240 K.