Electrochemical gating: A method to tune and monitor the (opto)electronic properties of functional materials

Abstract

Electrochemical polarization of a crystalline, polymeric or nanoporous system or a single molecule may change the density of charge carriers in a controlled way, and hence the optical and electrical properties. If the system has two contacts, its electronic conductivity can be measured in situ as a function of the charge carrier density that is varied by the electrochemical potential. This is called electrochemical gating. Such investigations can reveal the nature of the charge carriers (mobile or localized) and the mechanism of electronic conduction. Here, we present a brief review of a number of systems including inorganic crystals, polymers, nanoporous quantum-dot solids, and single molecules for which electrochemical gating was used successfully in the study of the electronic properties.

Physical electrochemistry of nanostructured devices

“…8(a). 7,58,79 These regions can be controlled as independent working electrodes. Then it is possible to govern the Fermi level in the film with a bias U 1 D U 2 as in Fig.…”

“…The paper presents an introduction to the subject exposing an array of experimental methods and theoretical concepts that have emerged in recent years while studying such devices, particularly around the subjects of Fermi level displacement and electron transport. Recent reviews on physical properties of DSC, 5,6 electrochemical gating, 7 and the electrochemical determination of the density of states (DOS), 8 describe these related issues in more detail, and in another paper 9 I discuss a broad range of applications of metal-oxide nanoparticles in electrochemical devices. Here, emphasis is made to relating the macroscopic quantities measured by physical-electrochemical methods to the electronic and ionic properties of nanostructured devices and in particular of DSC.…”

Interpretation of electron diffusion coefficient in organic and inorganic semiconductors with broad distributions of states

“…This can be done at steady-state by electrochemical gating, 84,85 or as the low-frequency resistance in impedance spectroscopy (IS). 86 (2) The chemical capacitance is measured as a relation of charge DQ to voltage DV, when the voltage displaces the Fermi level.…”

The Role of Nanostructure in Improving the Performance of Electrodes for Energy Storage and Conversion

“…[146] ECG is a known method to tune and monitor the (opto)-electronic properties of functional materials. [147] Electrochemical interfaces usually consist of a solid-phase electron conductor in contact with an ionic solution. In practice, the solid can be placed as working electrode in a conventional three-electrode electrochemical cell; its electrochemical potential is controlled by applying a voltage (V) with respect to a reference electrode ( Figure 10).…”