Enhanced tunability of the multiphoton absorption cross-section in seeded CdSe/CdS nanorod heterostructures
Chou, Kok Loong
Huan, Alfred Cheng Hon
Sum, Tze Chien
Date of Issue2010
School of Physical and Mathematical Sciences
We present a method to separately tune the multiphoton absorption (MPA) and multiphoton excited photoluminescence using semiconductor core/enlarged-shell quantum dots (QDs), where the enlarged shell greatly enhances the MPA cross-sections while varying the core size facilitates emission wavelength selectivity. Following two-photon absorption (2PA) primarily in the shell and ultrafast charge-carrier localization to the core, luminescence occurs. We exemplify the validity of this method with CdSe/CdS nanorod heterostructures and find that the 2PA cross-section is enlarged to ∼ 1.4×10^6 GM for 180 nm nanorods (with 800 nm, 150 fs laser pulse excitation) which is two to four orders larger than that of CdSe QDs.
DRNTU::Engineering::Materials::Microelectronics and semiconductor materials
Applied physics letters
© 2010 American Institute of Physics. This paper was published in Applied Physics Letters and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at: [DOI: http://dx.doi.org/10.1063/1.3479048]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.