Enhancing the Stability of the Electron Density in Electrochemically Doped ZnO Quantum Dots
Solrun Gudjónsdóttir (TU Delft - ChemE/Opto-electronic Materials)
A. J. Houtepen (TU Delft - ChemE/Opto-electronic Materials)
Christel Koopman (Student TU Delft)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Electronic doping of semiconductor nanomaterials can be efficiently achieved using electrochemistry. However, the injected charge carriers are usually not very stable. After disconnecting the cell that is used for electrochemical doping the carrier density drops, typically in several minutes. While there are multiple possible causes for this, we demonstrate here, using n-doped ZnO quantum-dot films of variable thickness that the dominant mechanism is reduction of solvent impurities by the injected electrons. We subsequently investigate two different ways to enhance the doping stability of ZnO QD films. The first method uses preemptive reduction of the solvent impurities; the second method involves a solid covering the QD film, which hinders impurity diffusion to the film. Both methods enhance the doping stability of the QD films greatly