Investigation of the semiconductor–oxide electrolyte interface in GaAs utilizing electrolyte electroreflectance

Publisher Website
Google Scholar
Abstract
We have investigated the electrolyte electroreflectance (EER) spectra of N–GaAs in the vicinity of the Eo transition (direct gap at k↘=0). A pronounced interference phenomenon sensitive to the dc bias electric field has been observed which we identify with an exciton quenching effect within the semiconductor space–charge region (SCR). We have utilized this excitonic feature to interferometrically probe the dynamic and steady-state properties of the SCR during electrochemical anodization procedures. The same EER spectra also exhibit Franz–Keldysh oscillations, the period of which is explicitly dependent on the ac electric field. Using these phenomena we have shown that the interfacial and oxide electric fields under steady-state conditions are just sufficient to continue growing the oxide in compensation for slow dissolution. If the dc bias voltage is suddenly reduced, the SCR temporarily collapses due to transient effects which we attribute to very slow interface states in the oxide. These techniques are applicable to the study of the SCR in a variety of semiconductor–electrolyte systems as well as in the Schottky barrier configuration.

This publication has 0 references indexed in Scilit: