We have observed enhanced biexcitonic effect in CdS0.6Se0.4 nanocrystals by means of femtosecond two-photon pump-probe spectroscopy. In contrast to a weak biexcitonic photoinduced absorption in the presence of |1Se1Sh〉 or |1Pe1Ph〉 excitons due to one-photon excitation, we have found a pronounced photoinduced absorption arising from a strong Coulomb coupling between a |1Se1Sh〉 exciton and a two-photon excited |1Se1Ph〉 exciton. We have also theoretically shown that |1Se1Sh;1Se1Ph〉 biexcitons have a large binding energy compared with |1Se1Sh;1Se1Sh〉 and |1Se1Sh;1Pe1Ph〉 biexciton states.
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2001 Jul 15|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics