Niobium Doped Ti O, (Nb:Ti02) Effects of Doping Concentration on the Optical Properties of Ti O2
Date
28-04-14Author
Ajuoga, P
Ogacho, A
Mwabora, J
Aduda, B
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
The optical band gaps and crystal structure were inve stig ated on niobium doped TiO~ (for atomic niobium
concentrations ranging from 0.02 -0.06 at. % in the composite) prepared by high temperature diffusion
method. The Nb:Ti02 films displayed an enhanced visible light absorption \\ ith a red shift of I S.l I1Ill of
the optical absorption edge from 39~ nrn for pure TiCh film to 4 J 2:2 nrn for 0.04 at % niobium
concentration representing a band gap lowering of 0 J S J eV due to the donor -t , pe behavior or niobium.
:\s the niobium concentration increased. the enhancement in light absorption at the inve sug ated
• onccmration range goes through a maximum at 004 at. ';0 ofNbS- with ill In nnurn band gap of3 !Ji/t'V
Despite higher rutilization. at the doping temperature of 850°C used. cr:~t," sizes (39-43 nm ) obtained
lrorn :\-ray diffraction spectra depicted a significant increase in surface areas which is anribured t()
rciardat ion of anatase - rutile phase transformation caused bv NbTiO? m auix