The interfacial structure of InP(100) in contact with HCl and H₂SO₄ studied by reflection anisotropy spectroscopy

Abstract

Electrochemical reflection anisotropy spectroscopy reveals the reversible re-structuring of InP surfaces in contact with low-concentration electrolytes upon applied potentials, while higher concentrations induce non-reversibility.

Experimental and Computational Aspects of Electrochemical Reflection Anisotropy Spectroscopy: A Review

“…The electrochemical measurements were done with a potentiostat (Versa STAT 3F from AMETEK). Further details of the experimental procedure can be found elsewhere [57] …”

“…In Figure (b), the cathodic current for the corresponding CV in the voltage range between −0.4 V to −1.3 V can be ascribed to the reduction of InP into phosphine and metallic In. The latter can then further react with HCl to form an InCl interfacial film starting from potentials lower than −0.4 V vs. (Ag/AgCl) [57] . The cathodic current density starting from around −0.4 V and reaching a plateau at −1.3 V is associated with the hydrogen evolution reaction.…”

“…Therefore, we have chosen InP(100) as a first case study for an electrochemical RAS analysis, as it is available in high single‐crystalline quality, but also subject to rapid electrochemical corrosion. A more detailed investigation with experimental details can be found in our recent publication [57] …”

“…A more detailed investigation with experimental details can be found in our recent publication. [57] Figure 6 (a) presents a 2D color-coded graphic (colorplot) showing continuously acquired RA spectra in situ under CV conditions. The starting point were samples prepared from epiready InP(100) wafers, but without pre-treatment of the surface prior to immersion into the electrolyte.…”

“…Here, the current density is limited in rate by the low overall photocurrent from the incident light of the spectrometer, while below À 1.7 V, the hydrogen production is no longer photo-current limited. [57] This highlights again the challenge that for a semiconductor, the optical probe can impact the photoelectrochemical response of the system under investigation.…”