Room temperature exciton formation in SnO2 nanocrystals in SiO2:Eu matrix: quantum dot system, heat-treatment effect.
SnO2 nanocrystals in SiO2:Eu matrix have been prepared at a relatively low temperature of 170 degrees C for 4 h. Selective transition probability of Eu3+ emission could be done after a suitable excitation wavelength. The room temperature exciton formation at 285 nm for as-prepared nanoparticles is observed and this gives the Bohr's radius of 1.4 nm. Exciton formation disappears for the nanoparticles heated at 500 and 900 degrees C. This is related to the increase in particle size with heat-treatment. A wide-band-gap (4.35 eV) quantum dots is obtained and will be important in photonics and UV-lasing application.
Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Raghumani Singh
RS
Ningthoujam
Rajesh Kumar
RK
Vatsa
Ajayan
A
Vinu
Katsuhiko
K
Ariga
Avesh Kumar
AK
Tyagi