
TY  - JOUR
A1  - Wood, Annabel 
A1  - Giersig, Michael 
A1  - Hilgendorff, Michael 
A1  - Vilas-Campos, Antonio 
A1  - Liz-Marzán, Luis M. 
A1  - Mulvaney, Paul 
T1  - Size Effects in ZnO: The Cluster to Quantum Dot Transition
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2003
VL  - 56
IS  - 10
SP  - 1051
EP  - 1057
KW  - 
UR  - https://doi.org/10.1071/CH03120 
N2  - The use of tetraalkylammonium hydroxides to prepare ZnO colloids with diameters ranging from 1 to 6 nm is described. The position of the first excitonic transition has been measured by UV-vis spectrometry and correlated with the particle size, which has been measured using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and ultracentrifugation (UC). The exciton transition is first visible at 265&#8211;270 nm corresponding to particle diameters around 1 nm; the exciton absorption band then becomes sharper and narrower, while the band red-shifts only slowly. Based on the sizing data from HRTEM, XRD, and UC, it is concluded that the quantum size effect at sizes less than the Bohr radius is significantly less than predicted from the Kayanuma equation. Based on the blue-shift in the trap emission as a function of nanocrystal size, the effective masses of the electron and hole (me, mh) remain constant in particles down to 1 nm in diameter, with a relative value given by me/(me+mh)=0.55 &#177; 0.04. 
ER  -

