Manipulating light emission of quantum dots by simultaneously controlling crystal morphology and doping

Abstract

This study reports the feasibility of manipulating light emission of spherical and non-spherical ZnSe quantum dots doped with iodine at the crystal surface or matrix. Experimental results suggested that photoluminescence of both spherical and non-spherical ZnSe quantum dots was significantly dependent on the dopant radial position. On the other hand, the crystal morphology was found to affect the doping state of iodine in the quantum dots. The doped iodine of the spherical and non-spherical quantum dots was mainly at the crystal surface and matrix, respectively. The spherical quantum dots doped with iodine exhibited photoluminescence at about 510 nm, while non-spherical ones showed much longer wavelength ($580 nm) and higher emission efficiency. The results reveal a new way to design luminescent materials via simultaneously controlling crystal morphology and doping.

Investigation of Luminescence Enhancement and Decay of QD-LEDs: Interface Reactions between QDs and Atmospheres

“…Transmission electron microscopy (TEM) and scanning transmission electron microscopy in the annular dark field (STEM-ADF) are employed to analyze the illuminated QDs in oxygen and The phenomenon is reasonable because photo-oxidation would lead to some amorphization of the QD near-surface region, which strongly influences the QD PL properties. 34 For QDs illuminated in wet N 2 and wet O 2 , a slight size decrease is perceived and is attributable to further photo-oxidation of QDs (Figure 3c,d). In addition, a fused-like appearance is observed for QDs illuminated in both H 2 Ocontaining atmospheres, as highlighted by the red squares in Figure 3c.…”

Roles of alcohols and existing metal ions in surface chemistry and photoluminescence of InP cores

“…The photo-excited carriers could delocalize to the lower energy radiative states, and a slight PL redshift is observed. 48,49 As the aging and oxidation process continue, the further blueshifted optical absorption suggests further decrease in InP NC size and a thicker surface oxidation layer, which might lead to further increase in PL intensity. A similar result that described PL enhancement of InP NCs after air exposure was reported previously.…”

Highly fluorescent QD probes labeling hepatocellular carcinoma cells

“…4,5 More importantly, QDs have fewer pitfalls than those found intrinsically in organic uorophores, and have a stronger uores-cence signal compared to organic dyes. Till now, although some studies have been made about QDs, 6,7 further work is necessary before QD probes can be practically applied in clinical practices.…”

“…The highly uorescent quantum dots (QDs) have been widely studied as an ideal candidate for cancer detection due to their unique size-tunable chemical and physical properties. 4,5 More importantly, QDs have fewer pitfalls than those found intrinsically in organic uorophores, and have a stronger uorescence signal compared to organic dyes. Till now, although some studies have been made about QDs, 6,7 further work is necessary before QD probes can be practically applied in clinical practices.…”