Hot carrier injection of photogenerated electrons at indium phosphide–electrolyte interfaces

Cooper, Gerald R.; Turner, John A.; Parkinson, B. A.; Nozik, Arthur J.

doi:10.1063/1.331928

Cited by 67 publications

(49 citation statements)

References 16 publications

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“…This is unlike at aqueous electrolyte interfaces with highly doped SrTiO 3 , Si, and InP where large light induced changes occur in C(V) at similar fluences. 50,57,58 Therefore, the TGS technique employed acts as a weak probe for the interfacial carrier diffusivity, without substantially altering the surface species during the measurement.…”

Section: Steady-state Photo-electrochemistrymentioning

confidence: 99%

Transient optical diffraction of GaN/aqueous interfaces: Interfacial carrier mobility dependence on surface reactivity

Doan

Pollock

Cuk

2016

Chemical Physics Letters

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While charge transport and surface reactivity have thus far been treated as independent phenomena, the interfacial carrier mobility could be highly dependent on reaction intermediates that carry localized charge and can hop from site to site along the surface. Here, we demonstrate the use of surface sensitive transient optical grating spectroscopy to measure this lateral, interfacial carrier diffusivity at surfaces with different reactivity. We find that for n-GaN, for which substantial charge transfer occurs during equilibration with the water oxidation reaction, the interfacial hole diffusivity increases from air by a factor greater than two under 0.1 M HBr and 0.1 M Na 2 SO 4 aqueous electrolytes.

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Section: Steady-state Photo-electrochemistrymentioning

confidence: 99%

Transient optical diffraction of GaN/aqueous interfaces: Interfacial carrier mobility dependence on surface reactivity

Doan

Pollock

Cuk

2016

Chemical Physics Letters

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“…The data were modeled to a series RC circuit, and the total measured capacitance was assumed to be equal to Csc (22). Values of Csc were recorded at 100 mV intervals using a cyclic staircase potential program with the step time equal to 10s, which was superimposed upon an ac signal with a frequency of 5 kHz and an amplitude of 20 mV peak to peak.…”

Section: /Cse 'Z = (2/eeeond)(e -Efb --Kbt/e)mentioning

confidence: 99%

The Effects of Surface Energetics on the Cyclic Voltammetry of Metallocenes at Nonilluminated n ‐ InP Electrodes

Koval

Austermann

1985

J. Electrochem. Soc.

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Electron transfer processes at n-type InP electrodes of moderate to low doping density were investigated by monitoring the cyclic voltammetric dark currents of a series of metallocenes in acetonitrile solutions. The formal reduction. potentials of the metallocenes span the bandgap of InP, allowing a comparison of the cyclic voltammetric response as a function of the formal reduction potential and the energetic condition of the electrode surface. The energetic condition of the electrode surface during the cyclic voltammetry experiments was monitored by measurements of the capacitance of the space charge region. A simple chemical etching and electrochemical cycling procedure yielded reproducible surface energetics. The n-InP/acetonitrile interface in the depletion condition responded ideally to changes in electrode potential, as evidenced by linear Mott-Schottky plots, over a range of about 0.9V. It was possible to achieve an accumulation condition at negative potentials, but the interface could not be inverted at positive potentials. The n-InP/acetonitrile interface is less susceptible to surface oxidation than is the p-InP/acetonitrile interface. For each metallocene + 1/0 couple, the reversibility of cyclic voltammetric (CV) waves at n-InP was dependent on the doping density of the electrode (ND) and the proximity of the formal reduction potential (E ~ to the conduction bandedge (EcB). Couples with E ~ located negative of EcB displayed nearly reversible CV waves. Couples with E ~ located in the bandgap were reduced irreversibly at overvoltages of 400-500 mV. A couple with E ~ located slightly positive of EcB yielded a partially reversible CV wave at moderate ND, but the wave became irreversible at low ND. Oxidation of couples with E ~ positive of -0.5V vs. E ~ for ferricenium/ferrocene was not observed.The kinetics of electron transfer processes at semiconductor electrode/solution interfaces have not received as much attention experimentally as redox processes at metal electrode/solution interfaces (1-13). We have previously reported our investigation of electron transfer processes at p-InP electrodes in acetonitrile solutions (1). Herein, we extend our study to electron transfer processes at the n-InP/acetonitrile interface.The purpose of this study is to investigate the ways that heterogeneous charge transfer kinetics at semiconductor electrodes are affected by various combinations of the formal reduction potentials of solution species and the energetic condition of the electrode surface. Our approach has been to measure cyclic voltammetric dark currents in acetonitrile solutions for ferricenium § cobalticenium +, and a number of their derivatives (Fig. 1) at n-InP electrodes of moderate to low doping density. Abbreviated designations and formal reduction potentials, E ~ for the metallocenes are listed in Table I. The reasons behind our choices of InP as the electrode material and the series of metallocenes as solution redox probes have been discussed before (1).The specific knowledge of the energetics of the ...

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“…They encompass fundamental investigations of semiconductor-electrolyte junctions, 1,2 the first light-assisted water splitting, 3 photoemission from metals into solution, 4,5 hot electron processes 6,7 and the first carbon dioxide reduction at illuminated semiconductors. 8,9 The conceptual basis of energy conversion at the solid-liquid junction was provided by Gerischer in 1975 when the rectifying nature of the semiconductor-redox electrolyte contact was outlined.…”

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confidence: 99%

Semiconductor Surface Transformations for Photoelectrochemical Energy Conversion

Lewerenz¹

2014

J. Electrochem. Soc.

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The issue of photoelectrode stability, while simultaneously maintaining efficient operation in aqueous solutions, is addressed for energy converting half cells and complete photoelectrocatalytic structures. The historical development of stability concepts, their realization and recent advances are described. Examples are presented that span the time from the inception of photoelectrochemical energy conversion to present day's renewed interest in storable solar energy. The application of (photo)corrosion processes for in-situ synthesis of protective coatings is described and chemical and electronic analyses of the interphases formed are given. Future development and innovation routes will be discussed. The early days of light-induced processes at the solid-electrolyte interface were characterized by a series of fascinating effects. They encompass fundamental investigations of semiconductor-electrolyte junctions, 1,2 the first light-assisted water splitting, 3 photoemission from metals into solution, 4,5 hot electron processes 6,7 and the first carbon dioxide reduction at illuminated semiconductors. 8,9 The conceptual basis of energy conversion at the solid-liquid junction was provided by Gerischer in 1975 when the rectifying nature of the semiconductor-redox electrolyte contact was outlined.1 The elegance of formation of a conformal contact, simply by immersion of the samples into solution, was, however, neutralized by interfacial reactivity that gives rise to photocorrosion. 10,11 In the early assessment of stability of semiconductors at electrolyte junctions, thermodynamic decomposition potentials were introduced and their energy relation relative to the semiconductor band edges was analyzed.10,12 It soon turned out that stability is a predominant and major issue in photoelectrochemical energy conversion in both the photovoltaic and photoelectrocatalytic modes. Early development of stable photoelectrodes, based on the group VIb transition metal dichalcogenides, [13][14][15] which are also characterized by high absorptivity, was compromised by the problem of scalable preparation of efficient electrodes. Technologically advanced semiconductors from the III-V and II-VI groups typically showed rather high conversion efficiencies [16][17][18] but, also, often pronounced photocorrosion.19 A promising approach for stabilization was developed by the Bell Laboratories group where ∼ 10% efficient InP photocathodes had been operated for extended time in aqueous solution. 20The employed conditioning method resulted in the formation of interfacial films 21 that enabled electron transfer but that blocked access of solution components to the absorber surface thereby suppressing the corrosion reactions.In this text, fundamental aspects and recent developments and advances of this method will be outlined and discussed. Basic concepts on stability and photocorrosion are presented first, followed briefly by a discussion of carrier transport across interfacial films. A subsequent section describes the chronological development of ...

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Hot carrier injection of photogenerated electrons at indium phosphide–electrolyte interfaces

Cited by 67 publications

References 16 publications

Transient optical diffraction of GaN/aqueous interfaces: Interfacial carrier mobility dependence on surface reactivity

Transient optical diffraction of GaN/aqueous interfaces: Interfacial carrier mobility dependence on surface reactivity

The Effects of Surface Energetics on the Cyclic Voltammetry of Metallocenes at Nonilluminated n ‐ InP Electrodes

Semiconductor Surface Transformations for Photoelectrochemical Energy Conversion

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