Limits...
Synthesis and characterization of zinc oxide thin films for optoelectronic applications

View Article: PubMed Central - PubMed

ABSTRACT

Micro-ring structured zinc oxide (ZnO) thin films were prepared on glass substrates by spray pyrolysis and their structural, morphological, optical and electrical properties were investigated. X-ray Diffraction (XRD) analysis revealed the films’ hexagonal wurtzite phase with a preferred (002) grain orientation. The mean crystallite size calculated on the basis of the Debye-Scherrer model was 24 nm and a small dislocation density of 1.7×10−3  nm−2 was obtained, indicating the existence of few lattice defects and good crystallinity. Scanning Electron Microscopy (SEM) micrographs revealed the film’s granular nature composed of rod-shaped and spherical nanoparticles which agglomerated to form micro-ring like film clusters on the film surface. The average transmittance in the visible region, optical band gap and Urbach energy were approximately 75–80%, 3.28 eV and 57 meV, respectively. The refractive index and extinction coefficient were determined using Swanepoel’s envelope method. Raman spectroscopy revealed the presence of small amounts of residual tensile stress and low density of defects in the ZnO thin films. This was consistent with XRD analysis. A low sheet resistivity (6.03×101  Ωcm) and high figure of merit (4.35×10−6  Ω−1) were obtained for our films indicating their suitability in optoelectronic applications.

No MeSH data available.


Related in: MedlinePlus

The SEM micrographs obtained at resolutions of (a) 200 nm, (b) 1 μm, (c) 2 μm, (d) 10 μm and (e) 20 μm, respectively.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5384418&req=5

fig0010: The SEM micrographs obtained at resolutions of (a) 200 nm, (b) 1 μm, (c) 2 μm, (d) 10 μm and (e) 20 μm, respectively.

Mentions: Fig. 2 shows SEM micrographs that were taken at resolutions of (a) 200 nm, (b) 1 μm, (c) 2 μm, (d) 10 μm and (e) 20 μm, respectively. All samples had a uniform crack free structure. Fig. 2(a) and (b) revealed the film’s granular nature consisting of uniformly distributed rod-shaped and spherical nanoparticles of around 400 nm length and 100 nm diameter, respectively. Fig. 2(c) − (e) revealed that the microstructure was not completely flat due to nanoparticles which piled up to form micro-ring structures of diameter approximately, 5–10 μm. This was comparable with ZnO micro-rings by Hossain et al. [17] which had diameters of 5–13 μm.


Synthesis and characterization of zinc oxide thin films for optoelectronic applications
The SEM micrographs obtained at resolutions of (a) 200 nm, (b) 1 μm, (c) 2 μm, (d) 10 μm and (e) 20 μm, respectively.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384418&req=5

fig0010: The SEM micrographs obtained at resolutions of (a) 200 nm, (b) 1 μm, (c) 2 μm, (d) 10 μm and (e) 20 μm, respectively.
Mentions: Fig. 2 shows SEM micrographs that were taken at resolutions of (a) 200 nm, (b) 1 μm, (c) 2 μm, (d) 10 μm and (e) 20 μm, respectively. All samples had a uniform crack free structure. Fig. 2(a) and (b) revealed the film’s granular nature consisting of uniformly distributed rod-shaped and spherical nanoparticles of around 400 nm length and 100 nm diameter, respectively. Fig. 2(c) − (e) revealed that the microstructure was not completely flat due to nanoparticles which piled up to form micro-ring structures of diameter approximately, 5–10 μm. This was comparable with ZnO micro-rings by Hossain et al. [17] which had diameters of 5–13 μm.

View Article: PubMed Central - PubMed

ABSTRACT

Micro-ring structured zinc oxide (ZnO) thin films were prepared on glass substrates by spray pyrolysis and their structural, morphological, optical and electrical properties were investigated. X-ray Diffraction (XRD) analysis revealed the films’ hexagonal wurtzite phase with a preferred (002) grain orientation. The mean crystallite size calculated on the basis of the Debye-Scherrer model was 24 nm and a small dislocation density of 1.7×10−3  nm−2 was obtained, indicating the existence of few lattice defects and good crystallinity. Scanning Electron Microscopy (SEM) micrographs revealed the film’s granular nature composed of rod-shaped and spherical nanoparticles which agglomerated to form micro-ring like film clusters on the film surface. The average transmittance in the visible region, optical band gap and Urbach energy were approximately 75–80%, 3.28 eV and 57 meV, respectively. The refractive index and extinction coefficient were determined using Swanepoel’s envelope method. Raman spectroscopy revealed the presence of small amounts of residual tensile stress and low density of defects in the ZnO thin films. This was consistent with XRD analysis. A low sheet resistivity (6.03×101  Ωcm) and high figure of merit (4.35×10−6  Ω−1) were obtained for our films indicating their suitability in optoelectronic applications.

No MeSH data available.


Related in: MedlinePlus