Study of reaction coupling and interfacial kinetics at semiconductor electrodes by band edge shift measurements

Allongue, P.; Blonkowski, S.; Lincot, Daniel

doi:10.1016/0022-0728(91)85399-a

Cited by 27 publications

(24 citation statements)

References 53 publications

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“…Jung and Kolb assumed jph,O = 10-l A/cm2 for mathematical simulations of experimentally observed sub-band-gap photocurrent curves at rutheniummodified electrode^.^^ This value can also be estimated from the band edge shift measurements of Allongue et al 54 Reichman used jph,o = lops Ncm2 for calculations of the photocurrentvoltage behavior. Jung and Kolb assumed jph,O = 10-l A/cm2 for mathematical simulations of experimentally observed sub-band-gap photocurrent curves at rutheniummodified electrode^.^^ This value can also be estimated from the band edge shift measurements of Allongue et al 54 Reichman used jph,o = lops Ncm2 for calculations of the photocurrentvoltage behavior.…”

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confidence: 99%

Computer simulation of the photoluminescence decay at the GaAs-electrolyte junction. 1. The influence of the excitation intensity at the flat band condition

Krueger¹,

Jung²,

Gajewski³

1994

J. Phys. Chem.

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The influence of excitation intensity, surface recombination velocity, and photocunent on the time-resolved photoluminescence (PL) at the nlGaAs-electrolyte junction under flat band conditions was investigated using computer simulations. The mathematical background of the two-dimensional semiconductor analysis package (TOSCA) will be presented. We will show that the effects may be characterized qualitatively by exponential fit function(s), although in most cases the simulated PL decay is nonexponential. For a free carrier concentration no = 5 x 1017 cmP3, under the conditions of low injection density (pi) and with flat bands, both the surface recombination and the photocurrent lead to a remarkable decrease in the PL decay time either for surface recombination velocities SO > lo3 cm/s or for exchange photocurrent densities j@,O > lo-'' A/cm2. Under the conditions chosen in this work, the PL decay time approximated by the monoexponential decay time T decreases to a minimum value in Tfin = 1.64 ns when SO I lo6 cm/s or jph,O L lov8 A/cm2. This minimum indicates that the diffusion of the minority carriers toward the surface where they immediately nonradiatively vanish by means of surface recombination and/or charge transfer, respectively, is limited by the thermal velocity. In both cases, diffusion competes effectively against bulk recombination. For injection levels (p,/no) > 0.1, the PL decay time decreases with increasing injection density because the quadratic recombination process dominates. At high injection densities, the surface recombination velocity may not remain constant during the PL decay, but instead varies as a function of time S(t); S may decrease from its maximum value (SO) by up to 1 order of magnitude during the PL decay. The results will be discussed in relation to experimental results published previously by other groups.

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confidence: 99%

Computer simulation of the photoluminescence decay at the GaAs-electrolyte junction. 1. The influence of the excitation intensity at the flat band condition

Krueger¹,

Jung²,

Gajewski³

1994

J. Phys. Chem.

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“… 41 These models exclusively focus on hole-induced decomposition (anodic decomposition) and also take into account the charge carrier generation and recombination (surface or bulk) processes. As multiple participating species 42 , 43 and interdependent steps 44 can be involved in the overall reaction scheme, it often becomes complex. Models rely on the description of the stepwise breaking of the back-bonds of surface atoms (following charge carrier generation).…”

Section: General Considerationsmentioning

confidence: 99%

“…Generally, the stabilization efficiency of a given redox pair is light intensity dependent. 44 , 58 , 59 As the light intensity increases, the branching ratio between photocorrosion and the redox reaction shifts in favor of the decomposition process. In comparison, the stabilization efficiency of redox couples in the case of layered 2D materials was independent from the light intensity.…”

Section: General Considerationsmentioning

confidence: 99%

“…The stabilization effect of redox couples can also be included in kinetic models, as either competing reactions for surface charge carriers or reactants that regenerate the partially broken surface bonds. Generally, the stabilization efficiency of a given redox pair is light intensity dependent. ,, As the light intensity increases, the branching ratio between photocorrosion and the redox reaction shifts in favor of the decomposition process. In comparison, the stabilization efficiency of redox couples in the case of layered 2D materials was independent from the light intensity .…”

Section: General Considerationsmentioning

confidence: 99%

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Photocorrosion at Irradiated Perovskite/Electrolyte Interfaces

Samu

Janáky

2020

J. Am. Chem. Soc.

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Metal−halide perovskites transformed optoelectronics research and development during the past decade. They have also gained a foothold in photocatalytic and photoelectrochemical processes recently, but their sensitivity to the most commonly applied solvents and electrolytes together with their susceptibility to photocorrosion hinders such applications. Understanding the elementary steps of photocorrosion of these materials can aid the endeavor of realizing stable devices. In this Perspective, we discuss both thermodynamic and kinetic aspects of photocorrosion processes occurring at the interface of perovskite photocatalysts and photoelectrodes with different electrolytes. We show how combined in situ and operando electrochemical techniques can reveal the underlying mechanisms. Finally, we also discuss emerging strategies to mitigate photocorrosion (such as surface protection, materials and electrolyte engineering, etc.).

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“…[23] They concluded that the photocorrosion current varied between al inear (in 0.5 m H 2 SO 4 )a nd aq uadratic (in 1 m KOH) dependence on charge density.A llongue et al showedt hat surface effects may strongly affect the reaction scheme of photocorrosion by using band-edge shift measurements coupled with stabilizationm easurements on n-GaAs photoanodes in contact with various redox solutions. [24] Allongue and Blonkowski proposed and experimentally validated a reactionm odel fort he photocorrosion reaction of III-V compounds,w hich quantitatively represented the Ta fel plots of current versus band displacement. [25] They described photocorrosion as an initial hole capture process on ac ation site, which becomes an anion site through liberation of the cation, and a chemicalr eactions tep that occurs before as econd hole capture proceeds to dissolve the anion-related defect.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Competition between Water‐Splitting and Photocorrosion Reactions in Photoelectrochemical Devices

Nandjou

Haussener

2019

ChemSusChem

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Semiconductor photocorrosion is a major challenge for the stability of photoelectrochemical water‐splitting devices. Usually, photocorrosion is studied on the basis of thermodynamic aspects, by comparing the redox potentials of water to the self‐decomposition potentials of the semiconductor or analyzing the equilibrium phases at given electrolyte conditions. However, that approach does not allow for a prediction of the decomposition rate of the semiconductor or the branching ratio with the redox reaction. A kinetic model has been developed to describe detailed reaction mechanisms and investigate competition between water‐splitting and photocorrosion reactions. It is observed that some thermodynamically unstable semiconductors should photocorrode in a few minutes, whereas others are expected to operate over a period of years as a result of their extremely low photocorrosion current. The photostability of the semiconductor is mainly found to depend on surface chemical properties, catalyst activity, charge carrier density, and electrolyte acidity.

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Study of reaction coupling and interfacial kinetics at semiconductor electrodes by band edge shift measurements

Cited by 27 publications

References 53 publications

Computer simulation of the photoluminescence decay at the GaAs-electrolyte junction. 1. The influence of the excitation intensity at the flat band condition

Computer simulation of the photoluminescence decay at the GaAs-electrolyte junction. 1. The influence of the excitation intensity at the flat band condition

Photocorrosion at Irradiated Perovskite/Electrolyte Interfaces

Kinetic Competition between Water‐Splitting and Photocorrosion Reactions in Photoelectrochemical Devices

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