Related Experiment Video
Updated: May 9, 2026

Ambient Method for the Production of an Ionically Gated Carbon Nanotube Common Cathode in Tandem Organic Solar Cells
Published on: November 5, 2014
Radical formation at the gallium nitride nanowire-electrolyte interface by photoactivated charge transfer
J M Philipps1, G M Müntze, P Hille
1I. Physikalisches Institut, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Gießen, Germany. jan.m.philipps@physik.uni-giessen.de
Abstract:
We investigated the transfer of photogenerated charge carriers from GaN nanowires into a surrounding electrolyte by electron paramagnetic resonance (EPR) and fluorescence spectroscopy. Using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap we find that the formation of hydroxyl radicals dominates in acidic, neutral and moderately basic environments, while in an electrolyte with a pH of 13.5 the superoxide formation becomes detectable. We explain the two processes considering the redox potentials for radical formation in the electrolyte as well as the positions of the conduction and valence bands. The role of surface band bending and surface states in the semiconductor is discussed.
Related Concept Videos
Radical Formation: Addition
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an unpaired...
Radical Formation: Overview
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the latter, also known...
Radical Formation: Abstraction
Even though homolysis produces radicals, it is different from radical...
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Radical Reactivity: Nucleophilic Radicals
Radical Reactivity: Overview

