CdSe nanoclusters

Leung K, Pokrant S and Whaley K B 1998 Exciton fine structure in CdSe nanoclusters Phys. Rev. B 57 12 291... 

Detailed analysis of x-ray diffractometry reveals the local structure of semiconductor clusters. Bawendi et al. (21) applied the method to CdSe nanoclusters of 3.5-4.0 nm. They concluded that these clusters have a mixture of crystalline structures intermediate between zincblende and wurtzite, on the basis of detailed simulation studies taking the thermal fluctuation into account. Conventional diffractometry could overlook the coexistence of wurtzite component. 

The effect of temperature on deep trap emission is similar to that observed for bandgap emission, with the intensity of the emission decreasing as the temperature increases. This can be explained by the involvement of nonradiative recombination processes dominating at higher temperature. Nonradiative relaxation in CdSe nanoclusters has been assigned to the involvement of a multiphonon relaxation mechanism mediated by a vibrational mode of the surface phenylse-lenolate ligands. ... 

CdSe nanocluster-adenine complexes UV-Vis B3LYP/6-31U-l-G , LanL2DZ 193... 

Fig. 7 Middle CD spectra of L-Cys-CdSe (red curves) and D-Cys-CdSe (blue curves) and DFT optimized geometries of (left) L-Cys-(CdSe)i3 and (right) D-Cys-(CdSe)i3 nanoclusters. Reprinted with Permission from Balaz et a/. Copyright 2013 American Chemical Society.

Fig. 5.2 (a) Typical absorption spectrum of CdSe nanocrystal QDs (Data from Jorge et al. 2007. Published by MDPI. Open access.), (b) Photoluminescence spectra of ZnS nanoparticles and ZnS nanoclusters in zeolite Y (X =280 nm) (Reprinted with permission from Chen et al. 1997, Copyright 1997 American Institute of Physics)... 

In the field of bio-nanotechnology, dendritic disulfides made from biocompatible L-lysine building-blocks were also found as useful ligands for the controlled assembly of gold nanoparticles [66] with anion sensing properties [67]. The synthesis of CdSe dendron stabilized nanoclusters with high stability and biocompatibility (box-nanocrystals) is also noteworthy [68]. 

Many II-VI semiconductor materials crystallize either in the cubic zinc-blende or in the hexagonal wurtzite structure often there is a competition between these two modifications as in ZnS, ZnSe, CdS, and CdSe. Although nanocrystallites have not yet completed their evolution into bulk solids, several experimental studies suggest that they have the same stoichiometry and crystal structure as the bulk material. In this section, we will discuss the structural, electronic and optical properties of some representative II-VI and III-V bulk-like viz. zinc-blende and wurtzite semiconductor nanoclusters. ... 

---