Elucidation of the Mechanism of Quantum Dot Arrangement Based on Self-Assembly of an Azobenzene Derivative

The formation of well-defined nanostructures comprising assembled semiconductor quantum dots (QDs) is a challenging research task. Recently, we found that the introduction of pi-conjugated molecules with a self-assembly ability into small CdSe QDs led to the formation of highly ordered QD arrangements. Here, we demonstrate the in-depth coaggregation process of large-sized CdSe QDs and azobenzene derivative 1 possessing an amino group functioning as an adhesive to the QD surface. Upon mixing the above QDs with assembled azobenzene derivative 1 in apolar solvents, linearly arranged QD structures along assembled azobenzene derivative 1 were formed over time. In the formed coaggregates, efficient energy transfer between the arranged QDs occurred, as confirmed by a change in the emission spectra and lifetimes. Analysis of time-dependent emission properties revealed the coaggregation mechanism of QDs and 1.