Colloidal ZnO nanocrystals in dimethylsulfoxide: a new synthesis, optical, photo- and electroluminescent properties.
Stable colloidal solutions of zinc oxide in dimethylsulfoxide were synthesized via interaction between zinc(II) acetate and tetraalkylammonium hydroxides (alkyl-ethyl, propyl, butyl, and pentyl). Colloids of ZnO emit photoluminescence in a broad band with a maximum at 2.3-2.4 eV with quantum yields of up to 9-10% at room temperature and 15-16% at 80 K. The photoluminescence is supposed to originate from the radiative recombination of conduction band electrons with holes captured by deep traps having corresponding states in the band gap 1.0-1.2 eV above the valence band edge. The size of colloidal ZnO nanocrystals depends on the duration and temperature of the post-synthesis treatment and varies in the range of 3-6 nm. Growth of the ZnO nanocrystals can be terminated at any moment of the thermal treatment by freezing the colloidal solution or by addition of tetraethyl orthosilicate which hydrolyses forming core-shell ZnO@SiO2 particles. ZnO nanocrystals introduced into polyethyleneimine films can be used as an active component of an LED emitting at an applied voltage higher than 13 V.
L V Pysarzhevsky Institute of Physical Chemistry of National Academy of Sciences of Ukraine, Prospekt Nauky 31, 03028 Kyiv, Ukraine.
Y V
YV
Panasiuk
O E
OE
Raevskaya
O L
OL
Stroyuk
S Y
SY
Kuchmiy
V M
VM
Dzhagan
M
M
Hietschold
D R T
DR
Zahn
D015415:Biomarkers / Q000737:chemistry; D002412:Cations; D003102:Colloids / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D006868:Hydrolysis; D008027:Light; D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology; D055668:Photochemical Processes; D011094:Polyethyleneimine / Q000737:chemistry; D012542:Scattering, Radiation; D012821:Silanes / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry*
D015415:Biomarkers; D002412:Cations; D003102:Colloids; D012821:Silanes; C040733:tetraethoxysilane; D011094:Polyethyleneimine; D015034:Zinc Oxide; D004121:Dimethyl Sulfoxide