Electrochemical techniques for the elucidation of the interface structure of the n-InP/aqueous electrolyte junction

Iranzo-Marín, F.; Debiemme‐Chouvy, Catherine; Herlem, M.; Sculfort, J. L.; Etchéberry, Arnaud

doi:10.1016/0022-0728(93)02996-u

Cited by 12 publications

(18 citation statements)

References 20 publications

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“…In aqueous media, the high chemical stability of a bare InP surface provided reproducible interfacial capacitance. 14,23 As was shown in the inset graph of Figure 1, the average change of the flatband potential was reported against the pH. A quasi Nernstian variation of the flatband potential on undoped n-InP was also observed in the whole range of pH (Fig.…”

Section: Resultsmentioning

confidence: 73%

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Photopotential Measurements on Undopedn-InP at Open Circuit Potential According to the Aqueous pH

Meldeje¹,

Gonçalves²,

Simon³

et al. 2018

J. Electrochem. Soc.

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In this work we studied some fundamental concepts of n-InP interfacial properties based on acid-base equilibrium in the dark and also after the surface illumination at open circuit voltage (Voc). The variation of the flatband potential on undoped n-InP semiconductor was investigated according to aqueous pH. This study was complemented by the effect of the illumination at Voc conditions through photopotential measurements. The impact of the surface lighting on acid-base equilibrium was analyzed by in-situ interfacial capacitance measurements in the dark and by ex-situ X-ray photoelectron spectrometry. The fundamental properties of many semiconductor/electrolyte systems were monitored by the flatband potential position (E FB ). 1,2Its position governed the interfacial characteristics and controlled the electrochemical properties. A classical way of measuring the variation of the flatband potential position was to change the pH of the medium. Many semiconductors were actually sensitive to the variation of acid-base equilibrium.3-12 For III-V semiconductors such as binary (GaAs 3,5 or GaP 6,7 ) or ternary 8 compounds, the acid-base equilibrium was complicated by the specific adsorption sites which induced localized charges on the surface. 13 Previous works have shown a quasi Nernstian variation of the flatband potential on n-InP for (100) 14 and (111) faces 13 over the whole pH range in aqueous medium and also in non aqueous medium such as acetonitrile 15 and liquid ammonia. 16Acid-base equilibrium was studied in the dark from interfacial capacitance measurements in the depletion region avoiding faradaic transfer at the interface semiconductor/electrolyte. This included changing the voltage of the semiconductor artificially through the use of a potentiostat. The band bending owing to electron depletion in the semiconductor (SC) changed depending on the voltage. In the depletion region the Boltzmann relation described the distribution of electrons in the space charge region and the electric field was determined by Gauss'law. Poisson's equation could be solved within that region to give the Mott-Schottky equation that links the reverse square of the capacitance (C) to the interfacial polarization (E). 17 Under depletion conditions the flatband potential was actually deduced from C −2 = f(E) straight line which extrapolation gave E FB for a zero value of C −2 . There are other ways to evaluate the flatband potential such as measuring the photopotential at the open circuit voltage (Voc). As a function of radiation intensity the photopotential was the change in the Fermi level due to the promotion of electrons to the conduction band, and it reached theoretically a maximum at the flatband potential. 13,18 In this paper acid-base equilibrium were further discussed on undoped nInP in which the low doping level led to a space charge region strongly different as compared to high doped n-InP. 9,[13][14][15][16]18 This was particularly true in terms of surface electrical field, charge, capacitance, layer of the space charge re...

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Section: Resultsmentioning

confidence: 73%

“…Just before experiment the surface is dipped in 2 M HCl solution then washed in pure water and dried under argon. 14 In-situ capacitance experiments were performed in aqueous media using a classical three-electrodes configuration. A platinum electrode was used as counter electrode.…”

Section: Methodsmentioning

confidence: 99%

Photopotential Measurements on Undopedn-InP at Open Circuit Potential According to the Aqueous pH

Meldeje¹,

Gonçalves²,

Simon³

et al. 2018

J. Electrochem. Soc.

Self Cite

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“…5 [7]. In opposite, InP, presents an "unexpected" slope of 40 mV [3] if we consider the whole pH range. Two nernstian V fb behaviors were nevertheless observed for limited ranges of pH (0-4) and (8)(9)(10)(11)(12)(13)(14) while in the neutral pH range a non-nernstian variation was still detected.…”

Section: Introductionmentioning

confidence: 87%

“…Two nernstian V fb behaviors were nevertheless observed for limited ranges of pH (0-4) and (8)(9)(10)(11)(12)(13)(14) while in the neutral pH range a non-nernstian variation was still detected. These behaviors revealed that a pure nernstian evolution depends essentially on the pH stability of the surface chemistry which supports the acid-base equilibrium [3]. According to the pH ranges, two different chemical compositions of InP surface were indeed determined by XPS chemical analyses.…”

Section: Introductionmentioning

confidence: 99%

“…In the literature, lot of examples of acid-base equilibrium at the semiconductor interface are related to an oxide (or hydroxide) surface [1][2][3][4][5][6] interface in aqueous solvents. This is obviously the case of semiconductor oxides like ZnO, TiO 2 , SnO 2 , WO 3 , where the interaction of their surfaces sites with H 3 O + or OH − , modified the structure of the electrical double layer as the pH of the solution change [1].…”

Section: Introductionmentioning

confidence: 99%

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