| 研究実績の概要 |
Aim of this project was to develop methods for efficient utilization of the energy of highly-excited nanoparticles (NPs) such as quantum dots (QDs) and perovskite nanocrystals (PNCs). Highly-excited NPs were generated by high-intensity laser irradiation. However, energy of such NPs is lost by ultrafast radiative and non-radiative recombination of photo-generated charge carriers. Therefore, extraction of absorbed energy towards practical applications is an important challenge. Here we developed photochemical and photophysical methods for extracting the energy of such NPs. At first, a part of the energy absorbed by QDs was extracted by activation of oxygen into singlet oxygen, which was followed by using singlet oxygen as the secondary energy source for chemical reactions. Here, we developed and used two novel singlet oxygen scavengers. Next, we applied highly-excited QDs to DNA molecules, which resulted in electron transfer from DNA to ionized QDs and formation of QD-DNA conjugates. Finally, we investigated stability of photo-generated charge carriers in highly-excited PNCs by preparation of self-assembled PNC structures. When compared with a PNC isolated in a solution, prolonged stability for photo-generated charge carriers was found for self-assembled structures, which is attributed to trapping or hopping of electrons and holes in or among PNCs. Successively, charge carriers in such PNCs were efficiently extracted by employing electron acceptors such as fullerene, which opens a method for efficient utilization of photoactivated PNCs for solar energy harvesting.
|
