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Structure and photoluminescence of the TiO2 films grown by atomic layer deposition using tetrakis-dimethylamino titanium and ozone.

Jin C, Liu B, Lei Z, Sun J - Nanoscale Res Lett (2015)

Bottom Line: The amorphous TiO2 film crystallizes to anatase TiO2 phase with annealing temperature ranged from 300°C to 1,100°C in N2 atmosphere, while the anatase TiO2 film transforms into rutile phase at a temperature of 1,000°C.Photoluminescence from anatase TiO2 films contains a red band at 600 nm and a green band at around 515 nm.A blue shift of the photoluminescence spectra reveals that the defects of under-coordinated Ti(3+) ions transform to surface oxygen vacancies in the anatase TiO2 film annealing at temperature from 800°C to 900°C in N2 atmosphere.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Weijin Road 94, Tianjin, 300071 China.

ABSTRACT
TiO2 films were grown on silicon substrates by atomic layer deposition (ALD) using tetrakis-dimethylamino titanium and ozone. Amorphous TiO2 film was deposited at a low substrate temperature of 165°C, and anatase TiO2 film was grown at 250°C. The amorphous TiO2 film crystallizes to anatase TiO2 phase with annealing temperature ranged from 300°C to 1,100°C in N2 atmosphere, while the anatase TiO2 film transforms into rutile phase at a temperature of 1,000°C. Photoluminescence from anatase TiO2 films contains a red band at 600 nm and a green band at around 515 nm. The red band exhibits a strong correlation with defects of the under-coordinated Ti(3+) ions, and the green band shows a close relationship with the oxygen vacancies on (101) oriented anatase crystal surface. A blue shift of the photoluminescence spectra reveals that the defects of under-coordinated Ti(3+) ions transform to surface oxygen vacancies in the anatase TiO2 film annealing at temperature from 800°C to 900°C in N2 atmosphere.

No MeSH data available.


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Dependences of the PL intensity and the anatase (101) peak intensity in XRD patterns on the growth temperature.
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Fig4: Dependences of the PL intensity and the anatase (101) peak intensity in XRD patterns on the growth temperature.

Mentions: The change of defects in the TiO2 films was characterized by measuring the room-temperature PL spectra at different growth temperatures. As it was shown in Figure 3, no PL emission was detected from the amorphous TiO2 films grown below 175°C. A green PL band at around 500 nm was observed from the TiO2 films with anatase phase grown at temperatures from 200°C to 300°C. In order to study the correlation between the PL and the structure change in the films, the dependences of PL peak intensity and the intensity of (101) anatase peak from the XRD patterns on the growth temperature are plotted together in Figure 4. The PL intensity increases with increasing substrate temperature, reaches a maximum at 250°C, and then decreases strongly at higher growth temperature, which is similar to the growth temperature dependence of the (101) anatase peak intensity in the XRD patterns. This similarity indicates that the defects related to the green PL band are probably located on the (101) oriented surface of the anatase TiO2 crystals. Finally, the strong quenching of the PL intensity at growth temperature over 250°C is probably due to the degradation of the anatase crystallinity by CVD, which causes an increase of the non-radiative recombination centers in the films.Figure 3


Structure and photoluminescence of the TiO2 films grown by atomic layer deposition using tetrakis-dimethylamino titanium and ozone.

Jin C, Liu B, Lei Z, Sun J - Nanoscale Res Lett (2015)

Dependences of the PL intensity and the anatase (101) peak intensity in XRD patterns on the growth temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385123&req=5

Fig4: Dependences of the PL intensity and the anatase (101) peak intensity in XRD patterns on the growth temperature.
Mentions: The change of defects in the TiO2 films was characterized by measuring the room-temperature PL spectra at different growth temperatures. As it was shown in Figure 3, no PL emission was detected from the amorphous TiO2 films grown below 175°C. A green PL band at around 500 nm was observed from the TiO2 films with anatase phase grown at temperatures from 200°C to 300°C. In order to study the correlation between the PL and the structure change in the films, the dependences of PL peak intensity and the intensity of (101) anatase peak from the XRD patterns on the growth temperature are plotted together in Figure 4. The PL intensity increases with increasing substrate temperature, reaches a maximum at 250°C, and then decreases strongly at higher growth temperature, which is similar to the growth temperature dependence of the (101) anatase peak intensity in the XRD patterns. This similarity indicates that the defects related to the green PL band are probably located on the (101) oriented surface of the anatase TiO2 crystals. Finally, the strong quenching of the PL intensity at growth temperature over 250°C is probably due to the degradation of the anatase crystallinity by CVD, which causes an increase of the non-radiative recombination centers in the films.Figure 3

Bottom Line: The amorphous TiO2 film crystallizes to anatase TiO2 phase with annealing temperature ranged from 300°C to 1,100°C in N2 atmosphere, while the anatase TiO2 film transforms into rutile phase at a temperature of 1,000°C.Photoluminescence from anatase TiO2 films contains a red band at 600 nm and a green band at around 515 nm.A blue shift of the photoluminescence spectra reveals that the defects of under-coordinated Ti(3+) ions transform to surface oxygen vacancies in the anatase TiO2 film annealing at temperature from 800°C to 900°C in N2 atmosphere.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Weijin Road 94, Tianjin, 300071 China.

ABSTRACT
TiO2 films were grown on silicon substrates by atomic layer deposition (ALD) using tetrakis-dimethylamino titanium and ozone. Amorphous TiO2 film was deposited at a low substrate temperature of 165°C, and anatase TiO2 film was grown at 250°C. The amorphous TiO2 film crystallizes to anatase TiO2 phase with annealing temperature ranged from 300°C to 1,100°C in N2 atmosphere, while the anatase TiO2 film transforms into rutile phase at a temperature of 1,000°C. Photoluminescence from anatase TiO2 films contains a red band at 600 nm and a green band at around 515 nm. The red band exhibits a strong correlation with defects of the under-coordinated Ti(3+) ions, and the green band shows a close relationship with the oxygen vacancies on (101) oriented anatase crystal surface. A blue shift of the photoluminescence spectra reveals that the defects of under-coordinated Ti(3+) ions transform to surface oxygen vacancies in the anatase TiO2 film annealing at temperature from 800°C to 900°C in N2 atmosphere.

No MeSH data available.


Related in: MedlinePlus