Aqueous synthesis of internally doped Cu:ZnSe/ZnS core–shell nanocrystals with good stability

et al. 2015

J Fluoresc

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Controllable doping is an effective way of tuning the properties of semiconductor nanocrystals (NCs). In this work, a simple strategy of fast doping Cu ions into ZnSe NCs under ambient conditions was proposed. The principle of doping is based on hydrazine (N2H4) promoted cation exchange reaction. By direct addition of Cu ion stock solution into the preformed ZnSe NCs, Cu doped ZnSe NCs can be obtained. Furthermore, the emission of doped NCs can be tuned by changing the amount of impurity ion addition. The cation exchange reaction is facilitated by three factors: 1) N2H4 addition, 2) fast impurity ions, and 3) partial stabilizer removal. The proposed cation exchange reaction in aqueous solution could be an alternate route for NC doping as well as synthesis of ionic NCs.

Section: Resultssupporting

confidence: 83%

“…NaHSe solution was prepared by using Se and NaBH 4 according to the reference methods [28,29]. Aqueous ZnSe NCs were synthesized according to the reference method [30,31].…”

Section: Synthesis Of Znse Ncsmentioning

confidence: 99%

Fast Doping of Cu into ZnSe NCs by Hydrazine Promoted Cation Exchange in Aqueous Solution at Room Temperature

Shao

et al. 2015

J Fluoresc

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“…In a previous study , we investigated the mechanism behind the weak stability of Cu:ZnSe QDs and reported the first example of aqueous Cu:ZnSe/ZnS QDs with excellent stability . The key to excellent stability in as‐prepared QDs is the simultaneous preparation of core–shell QDs and internally doped impurities.…”

Section: Introductionmentioning

confidence: 99%

Theoretical and experimental investigation of doping M in ZnSe (M = Cd, Mn, Ag, Cu) clusters: optical and bonding characteristics

et al. 2015

Luminescence

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The optical and bonding characteristics of doping ZnSe quantum dots (QDs) were investigated. Cd-, Mn-, Ag- and Cu-doped ZnSe were synthesized in aqueous solution. Theoretically, the intensity of the Cd-Se bond was similar to that of the Zn-Se bond, which illustrates that Cd can be doped into ZnSe materials at any ratio. We found that Mn-Se bonding was stronger than Zn-Se bonding. Ag-doped ZnSe nanoclusters show the same bonding and configuration as Cu-doped ZnSe. Moreover, Cd can be doped into ZnSe using both the substitution- and vacancy-doping method. For Mn-doped ZnSe clusters, small amounts of Mn impurity lead to stronger bonding with Se, but larger amounts of Mn impurity led to the formation of a Mn-Mn metal bond. The theoretical results show that it is difficult to form a vacancy-doping cluster for Mn-doped ZnSe materials. In experiments, the absorption and photoluminescence (PL) spectral wavelengths of Mn-doped ZnSe nanocrystals were the same as those of pure ZnSe nanocrystals, showing that the Mn impurity is not doped into ZnSe nanocrystals. Ag- and Cu-doped ZnSe nanocrystals have the same PL characteristics. The doping of an impurity is related to the solubility product, and not the bonding intensity.

“…This huge disadvantage makes these internally doped water-soluble Cu:ZnSe QDs impossible to apply in biology. Then, we reported the first example of water-soluble Cu:ZnSe/ZnS QDs with excellent stability [6]. The key for the excellent stability of as-prepared QDs is attributed to the simultaneous preparation of core-shell QDs and internally doped impurities.…”

Section: Introductionmentioning

confidence: 99%

Aqueous Synthesis of Nontoxic Ag2Se/ZnSe Quantum Dots Designing as Fluorescence Sensors for Detection of Ag(I) and Cu(II) Ions

Zhao

et al. 2014

J Fluoresc

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We reported the synthesis of water-soluble and nontoxic Ag(2)Se/ZnSe Quantum Dots (QDs) using for fluorescence sensors. The influences of various experimental conditions including the synthesis pH, types of ligand, feed ratios, and the refluxed time on the growth process and fluorescence of QDs were investigated in detail. Under optimal conditions, Ag(2)Se/ZnSe QDs show a single emission peak around 490 nm with the maximal photoluminescence (PL) quantum yield (QYs) of 13.7 %. As-prepared Ag(2)Se/ZnSe QDs can be used for detection of Ag(II) and Cu(II). The detection limits are 1 × 10(-6) mol/L to 5 × 10(-5) mol/L for Ag (I), and 2 × 10(-6) mol/L to 1.10 × 10(-4) mol/L for Cu(II).