CdTe—CdSe nanocrystals

Peng ZA, Peng XG (2001) Eormation of high-quahty CdTe, CdSe, and CdS nanocrystals using CdO as precursor. J Am Chem Soc 123 183-184... 

CdSe and CdTe nanocrystals can be prepared without precursor injection.71 The method involves refluxing the cadmium precursor with Se or Te in octadecene. CdSe nanocrystals have also been synthesized using elemental selenium dispersed in octadecene... 

Batvendi et al. first made monodisperse CdSe nanocrystals by rapid injection of a tri-n-octylphosphine (TOP) solution containing dimethylcadmium and tri-n-octylphosphine selenide into a hot solution of TOP and TOP oxide [47]. By a simple extension of this technique, CdTe and CdS nanocrystals can also be obtained... 

In bulk (or dispersed) heterojunctions, nanocrystals are blended into the polymer to create a heterogeneous composite with a high interface surface area. In this hybrid solar cell concept, photo induced charge separation is favored between high electron affinity inorganic semiconductors and relatively low ionization potential polymer. The maximum power conversion efficiency has reached 2.8 % under AM 1.5 illumination condition by using the composite of tetrapods of CdSe nanocrystals and MDMO-PPV [4], while the PCE of the device based on the composite of CdTe nanorods and MEH-PPV is only 0.052 % in similar conditions [5]. 

In type II (Figure 3.7b) core-shell nanocrystals, the VB or CB is either lower in energy or higher in energy. Therefore, localizing the hole in the core material and delocalizing the electron in shell as in the case of CdTe/ CdSe and CdSe/ZnTe [111]. 

Pseudo steady-state titration was found to be a valuable method for the determination of stability of colloidal nanocrystals upon change of the pH in the solutions [56]. CdSe nanocrystals coated with hydrophilic deprotonated thiol (thiolate) ligands were studied systematically. For comparison, CdTe and CdS nanocrystals coated with the same types of ligands were also examined. The results showed... 

CdTe/CdSe Core/Shell Nanocrystals Probed by 2DPE... 

The reactions used for synthesis of II-VI (CdSe, CdTe), III-V (InP, InAs), and IV-VI (PbS, PbSe, PbTe) semiconductor nanocrystals are outlined by Schemes 3-5.4,17,30-32 The syntheses are carried out at high temperatures, and in the presence of long-chain alkylphosphines (trioctylphosphine,TOP), alkyl-phosphine oxides (trioctylphosphine oxide, TOPO), alkylamines (hexadecyl-amine, HD A), and alkylphosphonic acids as the stabilizing agents. 

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