Controlling Charge-Transfer Processes at Semiconductor/Liquid Junctions

Hikmat S. Hilal, John A. Turner

Research output: Contribution to journalArticlepeer-review

31 Scopus Citations


The interfacial kinetics of charge transfer at n-GaAs/liquid junctions were controlled by anchoring positively charged species, such as tetra(-4-pyridyl)porphyrinatomanganese(III), with the semiconductor surface. Unlike earlier adsorption techniques, the charges have been chemically anchored to the semiconductor surface, in this work, via a ligand. The number of charges per site (attached molecule) ranged from +1 to +5. The positive charges shifted the band-edges towards more positive potential values. The degree of shift increased with surface charge density. In the dark, the flat band potential (measured by Mott-Schottky technique) and the onset potential were shifted by up to 300 mV depending on surface charge density. Relatively less of a shift was observed during illumination of the system. Other surface characteristics, such as conversion efficiency and photoluminescence intensity, have been enhanced. The basis for these shifts and their implications with respect to control of interfacial processes are discussed.

Original languageAmerican English
Pages (from-to)6487-6497
Number of pages11
JournalElectrochimica Acta
Issue number28
StatePublished - 2006

NREL Publication Number

  • NREL/JA-590-41013


  • Band-edges
  • Flat-band potential
  • Metalloporphyrins
  • Open-circuit potential
  • Semiconductor


Dive into the research topics of 'Controlling Charge-Transfer Processes at Semiconductor/Liquid Junctions'. Together they form a unique fingerprint.

Cite this