Limits...
Cohesive strength of nanocrystalline ZnO:Ga thin films deposited at room temperature.

Samantilleke AP, Rebouta LM, Garim V, Rubio-Peña L, Lanceros-Mendez S, Alpuim P, Carvalho S, Kudrin AV, Danilov YA - Nanoscale Res Lett (2011)

Bottom Line: The COS is similar for different GZO coatings and occurs for nominal strains approx. 1%.The cohesive strength of coatings, which was evaluated from the initial part of the crack density evolution, was found to be between 1.3 and 1.4 GPa.For these calculations, a Young's modulus of 112 GPa was used, evaluated by nanoindentation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro de Física, Universidade do Minho, Azurém, 4800-058 Guimarães, Portugal. anura@fisica.uminho.pt.

ABSTRACT
In this study, transparent conducting nanocrystalline ZnO:Ga (GZO) films were deposited by dc magnetron sputtering at room temperature on polymers (and glass for comparison). Electrical resistivities of 8.8 × 10-4 and 2.2 × 10-3 Ω cm were obtained for films deposited on glass and polymers, respectively. The crack onset strain (COS) and the cohesive strength of the coatings were investigated by means of tensile testing. The COS is similar for different GZO coatings and occurs for nominal strains approx. 1%. The cohesive strength of coatings, which was evaluated from the initial part of the crack density evolution, was found to be between 1.3 and 1.4 GPa. For these calculations, a Young's modulus of 112 GPa was used, evaluated by nanoindentation.

No MeSH data available.


Related in: MedlinePlus

The electrical resistivity, carrier concentration and Hall mobility for GZO/glass as a function of the Pw.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211395&req=5

Figure 3: The electrical resistivity, carrier concentration and Hall mobility for GZO/glass as a function of the Pw.

Mentions: The electrical resistivity, charge carrier concentration and Hall mobility as a function of the Pw, for GZO films deposited on glass, are shown in Figure 3. The resistivity of GZO samples decreased initially, and then increased with the Pw. In general, the average resistivity was low (approx. 10-4 Ω cm), which can be attributed to high carrier concentration. Considering the similarity in the conduction mechanism of electrons in GZO and ITO, the grain boundary (GB) and ionized impurity scattering processes can be considered the two dominant mechanisms, limiting electron transport in nc-GZO films, as in the case of ITO, where other scattering mechanisms such as lattice vibrations and neutral impurity scattering may typically be neglected [10]. The relative importance of the scattering mechanism is dependent on film quality and carrier concentration. Unlike intrinsic ZnO, where the conduction is generally controlled by GB-scattering, in doped ZnO at high electron density (>1020 cm-3), the ionized impurity scattering can be expected to dominate, which explains the low values of electron mobility (<10 cm2V/s) [11].


Cohesive strength of nanocrystalline ZnO:Ga thin films deposited at room temperature.

Samantilleke AP, Rebouta LM, Garim V, Rubio-Peña L, Lanceros-Mendez S, Alpuim P, Carvalho S, Kudrin AV, Danilov YA - Nanoscale Res Lett (2011)

The electrical resistivity, carrier concentration and Hall mobility for GZO/glass as a function of the Pw.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211395&req=5

Figure 3: The electrical resistivity, carrier concentration and Hall mobility for GZO/glass as a function of the Pw.
Mentions: The electrical resistivity, charge carrier concentration and Hall mobility as a function of the Pw, for GZO films deposited on glass, are shown in Figure 3. The resistivity of GZO samples decreased initially, and then increased with the Pw. In general, the average resistivity was low (approx. 10-4 Ω cm), which can be attributed to high carrier concentration. Considering the similarity in the conduction mechanism of electrons in GZO and ITO, the grain boundary (GB) and ionized impurity scattering processes can be considered the two dominant mechanisms, limiting electron transport in nc-GZO films, as in the case of ITO, where other scattering mechanisms such as lattice vibrations and neutral impurity scattering may typically be neglected [10]. The relative importance of the scattering mechanism is dependent on film quality and carrier concentration. Unlike intrinsic ZnO, where the conduction is generally controlled by GB-scattering, in doped ZnO at high electron density (>1020 cm-3), the ionized impurity scattering can be expected to dominate, which explains the low values of electron mobility (<10 cm2V/s) [11].

Bottom Line: The COS is similar for different GZO coatings and occurs for nominal strains approx. 1%.The cohesive strength of coatings, which was evaluated from the initial part of the crack density evolution, was found to be between 1.3 and 1.4 GPa.For these calculations, a Young's modulus of 112 GPa was used, evaluated by nanoindentation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro de Física, Universidade do Minho, Azurém, 4800-058 Guimarães, Portugal. anura@fisica.uminho.pt.

ABSTRACT
In this study, transparent conducting nanocrystalline ZnO:Ga (GZO) films were deposited by dc magnetron sputtering at room temperature on polymers (and glass for comparison). Electrical resistivities of 8.8 × 10-4 and 2.2 × 10-3 Ω cm were obtained for films deposited on glass and polymers, respectively. The crack onset strain (COS) and the cohesive strength of the coatings were investigated by means of tensile testing. The COS is similar for different GZO coatings and occurs for nominal strains approx. 1%. The cohesive strength of coatings, which was evaluated from the initial part of the crack density evolution, was found to be between 1.3 and 1.4 GPa. For these calculations, a Young's modulus of 112 GPa was used, evaluated by nanoindentation.

No MeSH data available.


Related in: MedlinePlus