Picosecond Electronic Relaxation in CdS/HgS/CdS Quantum Dot Quantum Well Semiconductor Nanoparticles
Title | Picosecond Electronic Relaxation in CdS/HgS/CdS Quantum Dot Quantum Well Semiconductor Nanoparticles |
Publication Type | Journal Article |
Year of Publication | 1996 |
Authors | Kamalov, VF, Little, RB, Logunov, SL, EL-Sayed, MA |
Journal | The Journal of Physical Chemistry |
Volume | 100 |
Issue | 16 |
Pagination | 6381 - 6384 |
Date Published | 1996 |
ISBN Number | 0022-3654 |
Abstract | Subpicosecond photoexcitation of CdS/HgS/CdS quantum dot quantum well nanoparticles at wavelengths shorter than their interband absorption (390 nm) leads to a photobleach spectrum at longer wavelengths (440?740 nm). The photobleach spectrum changes and its maximum red-shifts with delay time. These results are explained by the rapid quenching of the initially formed laser-excited excitons by two types of energy acceptors (traps); one is proposed to be due to CdS molecules at the CdS/HgS interface, and the other trap is that present in the CdS/HgS/CdS well. The results of the excitation at longer wavelengths as well as the formation and decay of the bleach spectrum at different wavelengths support this description.Subpicosecond photoexcitation of CdS/HgS/CdS quantum dot quantum well nanoparticles at wavelengths shorter than their interband absorption (390 nm) leads to a photobleach spectrum at longer wavelengths (440?740 nm). The photobleach spectrum changes and its maximum red-shifts with delay time. These results are explained by the rapid quenching of the initially formed laser-excited excitons by two types of energy acceptors (traps); one is proposed to be due to CdS molecules at the CdS/HgS interface, and the other trap is that present in the CdS/HgS/CdS well. The results of the excitation at longer wavelengths as well as the formation and decay of the bleach spectrum at different wavelengths support this description. |
URL | http://dx.doi.org/10.1021/jp953708m |
Short Title | J. Phys. Chem. |