Triplet-Exciton Energy Transfer from Semiconductor Nanocrystals Demonstrated Using Spectroscopy

Researchers at North Carolina State University, led by Prof. Felix Castellano, have shown for the first time that the photogenerated triplet exciton in semiconductor nanocrystals can be harvested by surface bound molecular acceptors, exhibited by a six-order magnitude increase in the lifetime of the originally prepared excited state. The research publication, featured in Science (1) and titled “Direct Observation of Triplet Energy Transfer from Semiconductor Nanocrystals,” highlights the use of carefully constructed materials and multiple spectroscopic techniques to measure and characterize the triplet exciton energy transfer from cadmium selenide (CdSe) semiconductor nanocrystals, prepared by Prof. Mikhail Zamkov and his group at Bowling Green State University, and surface bound 9-anthacenecarboxylic acid (ACA).

To observe the lifetime differences of CdSe nanocrystals and the CdSe-ACA energy transfer construct, the researchers utilized aTransient Absorption Spectrometer and MiniTau Fluorescence Lifetime spectrometer (Edinburgh Instruments); these instruments allowed for the detailed measurements of the lifetime increases associated with the triplet exciton energy transfer. Prof. Castellano, said that the results generated in this project on nanosecond and longer time scales were highly reproducible, and reliable.

Reference

• C. Mongrin, S. Garakyaraghi, N. Razgoniaeva, M. Zamkov, and F.N. Castellano, Science, 351, 369–372 (2016)