Influence of Metal Deposition on Electrochemical Impedance Spectra of Porous GaP and GaN Semiconductors

Abstract

A comparative analysis of electrochemical impedance spectroscopy (EIS) characterization is performed in porous GaN and GaP templates with and without metal nanostructured layers deposited by pulsed electroplating. The porous semiconductor templates are produced by electrochemical etching of bulk substrates. The EIS data are interpreted in terms of electrical equivalent circuits (EECs) deduced by fitting the experimental data from Nyquist plots. It is found that the EIS data of porous electrodes without electroplating are best fitted with EECs with both the charge transfer and mass transfer components of the Faradaic impedance, while electroplating reduces the importance of the mass transport component, i. e. of the Warburg impedance, associated with diffusion, in favor of the charge transport phenomena.