| 研究実績の概要 |
It was proposed that nanostructuring can resolve the bottleneck on the development of thermoelectric materials. This project aims at developing colloidal quantum dot (CQD) assemblies for high-performance thermoelectric (TE) devices. The keys towards the realization are the improvement of the assembly orders of the CQDs in both two-dimensions (2D) and three-dimensions (3D) arrangements; control of electronic coupling between the QDs; and the charge carrier doping on the QD assemblies. We improved the assembly quality, in particular for the 2D assemblies of the QDs. The use of new liquid/air interface assembly to selectively stripped the native ligands, and the development of new ligands to crosslink the QDs, significantly improved the domain size of the assemblies. Systematic investigation of the assembly mechanism and electronic transport were done. Through electrochemical transistor and spectroelectrochemistry measurements, we clarified the electronic energy degeneracy of the QD assemblies and the capability to fill them, electrostatically. Significant carrier doping was demosntrated by modifying the QD surface to form core-shell structure that exclusively select one type of charge transport with enhanced conductivity. These assembly and charge carrier doping strategies are vital for the development of TE materials based on the assemblies of CQDs. Further works proceeds to push more charge carrier doping via chemical means to match the prospect shown by electrostatic doping, in addition to develop well-ordered 3D assemblies required for practical thermoelectric devices.
|
