High efficiency and nearly cubic power dependence of below-band-edge photoluminescence in water-soluble, copper-doped ZnSe/ZnS quantum dots.
Three-photon absorption (3PA) and three-photon-excited photoluminescence (3PE-PL) of ZnSe/ZnS and copper-doped ZnSe/ZnS core-shell quantum dots (QDs) in aqueous solutions have been unambiguously determined by Z-scan and 3PE-PL measurements with 200-fs laser pulses at 1000 nm. The 3PA cross-section is as high as 3.5 x 10(-77) cm6 s2 photon(-2) for 4.1 nm-sized, copper-doped ZnSe/ZnS QDs, while their below-band-edge PL is found to be nearly cubic dependent on the excitation intensity, with efficiency enhanced by approximately 20 fold compared to the undoped ZnSe/ZnS QDs.
Xing
Guichuan
G
Department of Physics, National University of Singapore, Singapore 117542.
Ji
Wei
W
Zheng
Yuangang
Y
Ying
Jackie Y
JY
D003198:Computer Simulation; D017076:Computer-Aided Design; D003300:Copper / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008163:Luminescent Measurements / Q000295:instrumentation*; D008962:Models, Theoretical; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry* / Q000528:radiation effects; D012680:Sensitivity and Specificity; D013440:Sulfides / Q000737:chemistry* / Q000528:radiation effects; D014867:Water / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry* / Q000528:radiation effects
D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D014867:Water; D003300:Copper; C031238:zinc sulfide; C044696:zinc selenide