Title :
Observation of enhanced bleaching and fast recovery in CdS/sub 0.4/Se/sub 0.6/ nanocrystals
Author :
Young-Nam Hwang ; Cheon Min Kim ; Sae Chae Jeoung ; Dongho Kim ; Seung-Han Park
Author_Institution :
Nat. Creative Res. Initiatives Centre, Korea Stand. Res. Inst., Taejon, South Korea
fDate :
Aug. 30 1999-Sept. 3 1999
Abstract :
Semiconductor nanocrystals have been a subject of increasing interest due to various unique physical properties. Besides the quantum confinement in all three dimensions, various trapping processes are important factors to understand the ultrafast carrier dynamics in nanocrystals. The trapping into the surface states has been suggested to be a possible deactivation channel for the fast carrier relaxation in band-edge photoluminescence. Moreover, it is reported that photodarkening due to two photon absorption has been observed by trapping electrons into the glass electronic states. In our experiment, femtosecond transient absorption of CdS/sub 0.4/Se/sub 0.6/ nanocrystals in a glass matrix (Schott Glass RG630) has been measured to study the trapping effect on the bleaching dynamics.
Keywords :
II-VI semiconductors; cadmium compounds; high-speed optical techniques; nanostructured materials; optical glass; optical saturable absorption; photochromism; photoluminescence; semiconductor doped glasses; CdS/sub 0.4/Se/sub 0.6/ nanocrystals; Schott Glass RG630; band-edge photoluminescence; bleaching dynamics; deactivation channel; enhanced bleaching; fast carrier relaxation; fast recovery; femtosecond transient absorption; glass electronic state; glass matrix; nanocrystals; photodarkening; quantum confinement; surface state trapping; trapping effect; trapping electrons; trapping processes; two photon absorption; ultrafast carrier dynamics; Absorption; Bleaching; Electron traps; Glass; Laser excitation; Nanocrystals; Nonlinear optics; Optical control; Optical scattering; Ultrafast optics;
Conference_Titel :
Lasers and Electro-Optics, 1999. CLEO/Pacific Rim '99. The Pacific Rim Conference on
Conference_Location :
Seoul, South Korea
Print_ISBN :
0-7803-5661-6
DOI :
10.1109/CLEOPR.1999.811565
