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Effects of doping and annealing on properties of ZnO films grown by atomic layer deposition.

Wang A, Chen T, Lu S, Wu Z, Li Y, Chen H, Wang Y - Nanoscale Res Lett (2015)

Bottom Line: Annealing introduces O vacancies, decreases Zn interstitials, and results in weakening and blue-shifting of the UV emission which is sensitive to annealing atmosphere.It also introduces non-radiative centers and weakens the UV emission.Annealing has little effect on photoluminescence of the doped films, but it degrades undoped and doped ZnO film conductivity dramatically; and the degradation depends on the annealing ambient.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Beijing Normal University, Beijing, 100875 China.

ABSTRACT
Undoped and Al-doped ZnO films were synthesized by atomic layer deposition at 150°C and then annealed at 350°C in different atmospheres. Effects of doping and annealing on the film growth mode and properties were investigated. The undoped film has strong UV emission and weak Zn interstitial emission. Annealing introduces O vacancies, decreases Zn interstitials, and results in weakening and blue-shifting of the UV emission which is sensitive to annealing atmosphere. Al doping induces the film growing with its c-axis parallel to the substrate surface. It also introduces non-radiative centers and weakens the UV emission. Al doping widens the film bandgap, which has a quadratic dependence on Al content. Al doping decreases the film resistivity to 5.3 × 10(-3) Ω · cm. Annealing has little effect on photoluminescence of the doped films, but it degrades undoped and doped ZnO film conductivity dramatically; and the degradation depends on the annealing ambient.

No MeSH data available.


Related in: MedlinePlus

SEM images. (a) As-grown ZnO and (b) 3 at.% Al-doped ZnO films. High resolution images are also inserted; (c) undoped and (d) 3 at.% Al-doped films annealed in air; (e) undoped and (f) 3 at.% Al-doped ZnO film annealed in Ar.
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Fig3: SEM images. (a) As-grown ZnO and (b) 3 at.% Al-doped ZnO films. High resolution images are also inserted; (c) undoped and (d) 3 at.% Al-doped films annealed in air; (e) undoped and (f) 3 at.% Al-doped ZnO film annealed in Ar.

Mentions: The morphology of the films was observed by SEM. Typical images of undoped and 3 at.% Al-doped films are shown in Figure 3a,b. All films are comprised of uniform elongated grains. Otherwise, some grains of the undoped ZnO film have an inclination angle with the substrate surface. However, the grain sizes are much smaller and the elongated grains are mainly parallel to the substrate surface in Al-doped films. This demonstrates that Al doping would result in ZnO grains growing preferentially with c-axis parallel to the substrate surface. And it is consistent with that indicated in XRD spectra in Figure 1.Figure 3


Effects of doping and annealing on properties of ZnO films grown by atomic layer deposition.

Wang A, Chen T, Lu S, Wu Z, Li Y, Chen H, Wang Y - Nanoscale Res Lett (2015)

SEM images. (a) As-grown ZnO and (b) 3 at.% Al-doped ZnO films. High resolution images are also inserted; (c) undoped and (d) 3 at.% Al-doped films annealed in air; (e) undoped and (f) 3 at.% Al-doped ZnO film annealed in Ar.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385034&req=5

Fig3: SEM images. (a) As-grown ZnO and (b) 3 at.% Al-doped ZnO films. High resolution images are also inserted; (c) undoped and (d) 3 at.% Al-doped films annealed in air; (e) undoped and (f) 3 at.% Al-doped ZnO film annealed in Ar.
Mentions: The morphology of the films was observed by SEM. Typical images of undoped and 3 at.% Al-doped films are shown in Figure 3a,b. All films are comprised of uniform elongated grains. Otherwise, some grains of the undoped ZnO film have an inclination angle with the substrate surface. However, the grain sizes are much smaller and the elongated grains are mainly parallel to the substrate surface in Al-doped films. This demonstrates that Al doping would result in ZnO grains growing preferentially with c-axis parallel to the substrate surface. And it is consistent with that indicated in XRD spectra in Figure 1.Figure 3

Bottom Line: Annealing introduces O vacancies, decreases Zn interstitials, and results in weakening and blue-shifting of the UV emission which is sensitive to annealing atmosphere.It also introduces non-radiative centers and weakens the UV emission.Annealing has little effect on photoluminescence of the doped films, but it degrades undoped and doped ZnO film conductivity dramatically; and the degradation depends on the annealing ambient.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Beijing Normal University, Beijing, 100875 China.

ABSTRACT
Undoped and Al-doped ZnO films were synthesized by atomic layer deposition at 150°C and then annealed at 350°C in different atmospheres. Effects of doping and annealing on the film growth mode and properties were investigated. The undoped film has strong UV emission and weak Zn interstitial emission. Annealing introduces O vacancies, decreases Zn interstitials, and results in weakening and blue-shifting of the UV emission which is sensitive to annealing atmosphere. Al doping induces the film growing with its c-axis parallel to the substrate surface. It also introduces non-radiative centers and weakens the UV emission. Al doping widens the film bandgap, which has a quadratic dependence on Al content. Al doping decreases the film resistivity to 5.3 × 10(-3) Ω · cm. Annealing has little effect on photoluminescence of the doped films, but it degrades undoped and doped ZnO film conductivity dramatically; and the degradation depends on the annealing ambient.

No MeSH data available.


Related in: MedlinePlus