Generation of coherent current pulses and delayed switching in relaxation GaAsp+hyphen;ingr;hyphen;ndiodes

摘要

In GaAsp+hyphen;ngr;hyphen;ndiodes prepared from highhyphen;resistivity Crhyphen;doped GaAs, generation of coherent current pulses (CCP) has been observed in the forward bias regionVthquest;VVswand delayed switching in the regionVgsim;Vsw, whereVthis a threshold voltage for the CCP andVswis a threshold voltage for the switching. Coexistence of multiple components of the CCP with different interpulse times and pulse heights has been observed, which indicates that the CCP is caused by the periodic formation and annihilation of the filamentary current path. A doublehyphen;pulse experiment of the delayed switching has been performed using first and second identical pulses with varying pulsehyphen;separation time. For pulse heights slightly larger thanVsw, the delay time of the second pulse (td2) is larger than that of the first pulse (td1). Experimental results show that this peculiar relationtd2gsim;td1is due to an electronic process. These new nonlinear transport phenomena are closely related to each other. A model based on the concept of the relaxation semiconductor is proposed, taking into account the relationship between the dielectric relaxation time and the diffusion length lifetime in a transient state of the system involving two types of defect centers. Numerical estimations based on the model agree with the experimental values.