Student projects
Below is a list of available project for bachelor and master students. If you are interested, please contact the supervisor mentioned with the project.
The available projects change rapidly, so not all project may still be available and new projects may be possible.
Light emitting electrochemical cells made of QDs
A novel way of producing light is via light emitting electrochemical cells. Here electrons and holes are injected electrochemically at two different electrodes, and form a pin junction where they recombine and emit light. We have recently been one of the first groups to show that this can be done using quantum dots of CdSe/CdS/ZnS. We wish to consolidate these results, improve the efficiency, and especially show that this also works for non toxic QD like InP/ZnSe/ZnS and ZnSe/ZnS (see project above). This work involves some synthesis and surface treatments of QDs, but especially the formation of thin films via spin coating and completion of LEC devices using thermal evaporation of metal contacts.
Contact: Hua Chen (H.Chen-4@tudelft.nl)
Predicting charge transfer in quantum dots
Quantum dots (QDs) are semiconductor nanoparticles with interesting optoelectronic properties, particularly for applications related to photoelectrochemical energy conversion and photocatalytic devices. These devices can convert sunlight into electrical and chemical energy; when light is adsorbed, electron–hole pairs are produced in the QDs and transferred into redox molecules, producing a chemical change and an electrical current.
In theory, the electron transfer rate constant depends on the free energy; the Marcus model predicts an initial increase in the electron transfer with the free energy followed by a decrease as the free energy is further increased. Such device would therefore reach a maximum efficiency at the inflection point. The experimental relationship between the electron transfer rate constant and the free energy is however still not clear, the maximum rate constant is unknown, and the Marcus model has yet not been proven for electron transfer within QDs to redox molecules.
With this project you will put to test one of the most important theories of redox chemistry, the Marcus theory (1992 Nobel Prize in Chemistry), for the specific case of electron transfer within QDs to redox molecules. The work is multidisciplinary, involving areas from organic and inorganic synthesis to ultrafast spectroscopy and spectroelectrochemistry, and therefore we can accommodate your research area of preference.
Supervisor and contact: Yan Vogel (Y.B.Vogel@tudelft.nl).