TY - JOUR
T1 - Effect of compressive stress inducing a band gap narrowing on the photoinduced activities of sol-gel TiO films
AU - Ghazzal, M.N.
AU - Chaoui, N.
AU - Genet, M.
AU - Gaigneaux, E.M.
AU - Robert, D.
PY - 2011/11/30
Y1 - 2011/11/30
N2 - TiO thin films grown on different kinds of substrates were obtained by sol-gel process. X-ray diffraction revealed that the TiO lattice parameter c decreased continuously, indicating a continuous variation in the compressive stress, a negligible compressive stress of the film grown onto Soda-Lime Glass (SLG), medium compressive stress of the film grown onto BoroSilicate Glass (BSG) and large compressive stress of the film deposited onto the Quartz Substrate (QS). UV-Vis absorbance spectra exhibited a red-shift of the absorbance edge of the TiO films suggesting a lowering of the band gap, which is a direct consequence of the increase of the compressive stress. X-ray photoelectron spectroscopy revealed that the surface composition of titania films was similar except for sodium-ion concentration. The rate observed during the photo-oxydation of the stearic acid on TiO /QS was twice as high as that of TiO /BSG and about 1000 times superior to that of TiO /SLG. The photoinduced wettability shows an identical dependence of the compressive stress. According to these results, the compressive stress could be used to tune the band gap of the titanium oxide in order to enhance the photoinduced properties.
AB - TiO thin films grown on different kinds of substrates were obtained by sol-gel process. X-ray diffraction revealed that the TiO lattice parameter c decreased continuously, indicating a continuous variation in the compressive stress, a negligible compressive stress of the film grown onto Soda-Lime Glass (SLG), medium compressive stress of the film grown onto BoroSilicate Glass (BSG) and large compressive stress of the film deposited onto the Quartz Substrate (QS). UV-Vis absorbance spectra exhibited a red-shift of the absorbance edge of the TiO films suggesting a lowering of the band gap, which is a direct consequence of the increase of the compressive stress. X-ray photoelectron spectroscopy revealed that the surface composition of titania films was similar except for sodium-ion concentration. The rate observed during the photo-oxydation of the stearic acid on TiO /QS was twice as high as that of TiO /BSG and about 1000 times superior to that of TiO /SLG. The photoinduced wettability shows an identical dependence of the compressive stress. According to these results, the compressive stress could be used to tune the band gap of the titanium oxide in order to enhance the photoinduced properties.
UR - http://www.scopus.com/inward/record.url?scp=81855163373&partnerID=8YFLogxK
U2 - 10.1016/j.tsf.2011.08.097
DO - 10.1016/j.tsf.2011.08.097
M3 - Article
AN - SCOPUS:81855163373
SN - 0040-6090
VL - 520
SP - 1147
EP - 1154
JO - Thin Solid Films
JF - Thin Solid Films
IS - 3
ER -