A quantitative study of Fermi level pinning at a semiconductor-electrolyte interface

Semiconductor Electrodes: XLII . Evidence for Fermi Level Pinning from Shifts in the Flatband Potential of p‐Type Silicon in Acetonitrile Solutions with Different Redox Couples

“…These measurements of the flatband potential of p-Si in MeCN via capacitance-potential plots provide clear evidence of the Fermi level pinning model previously proposed. The shifts in the fiatband potential clearly parallel the shifts in the potential for the onset of the photocurrent and the observed cyclic voltammetric behavior for p-Si in CH3CN obtained in earlier studies (3,4). If only the oxidized form of the couple is present, the dark C-V behavior is similar to that for a solution in the absence of redox couples.…”

“…The concept of Fermi level pinning (FLP) was recently suggested to explain the relative independence of the open-circuit photopotential (Voc) at the semiconductor electrode in the presence of redox couples whose standard potentials span a range of potentials greater than the bandgap, Eg (1)(2)(3)(4). This behavior is different from that expected for the ideal semiconductor/electrolyte junction, where Voc = Vredox --VFB (Vredox is the potential of the solution redox couple and VFB is the flatband potential of the semiconductor in the absence of redox couple).…”

Open‐Circuit Photopotentials at Doped α ‐ Fe2 O 3 Electrodes in Aqueous Solution

“…The bulk properties of CuHCF, a PB analog, have been well studied and documented. Infrared, visible and ultraviolet spectroscopic (8)(9)(10), and x-ray crystallographic (11) data as well as physical properties of stability, solubility, and ion permeability (12) have been tabulated.…”

“…The model describing this behavior assumes pinning of the Fermi level in the semiconductor due to a high density of surface states around a certain potential. Studies dealing with the semiconductor/liquid junction were carried out mainly on nonoxide semiconductors (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) and the Fermi level pinning model was usually employed, in accordance with results obtained at the semiconductor/metal interfaces (6-8, 10 and references therein) for similar materials. However, fewer studies have been carried out on oxide semiconductors in contact with solution.…”

Semiconductor Ultramicroelectrodes: Platforms for Studying Charge-Transfer Processes at Semiconductor/Liquid Interfaces

“…The topic of semiconductor electrochemistry has been critical to advancing fundamental electrochemical concepts, including the nature of charged solid/liquid interfaces, heterogeneous reaction kinetics, photochemical processes, and corrosion/passivation . Semiconductor electrochemistry also is at the heart of many long-standing applied technologies such as semiconductor wet etching, − ion-sensitive field effect transistor sensors, , and photoelectrochemical energy conversion strategies. − Paradoxically, though, the ability to interpret readily, quantitatively, and unambiguously even the most basic voltammetric responses for charge transfer between a semiconductor electrode and a dissolved redox species is still a challenge. − …”