1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Strain-related optical properties of ZnO crystals due to nanoindentation on various surface orientations
Rent:
Rent this article for
USD
10.1063/1.4804309
/content/aip/journal/jap/113/18/10.1063/1.4804309
http://aip.metastore.ingenta.com/content/aip/journal/jap/113/18/10.1063/1.4804309

Figures

Image of FIG. 1.
FIG. 1.

Details of the indentation process. (a) Diagram of an indentation: is the projected contact area of the tip on the surface, is the radius of curvature, is the depth of the tip that is in contact with the crystal, and is the applied load. (b) Example of a nanoindentation curve taken on -plane ZnO: is the maximum applied load; is the maximum penetration depth; and is the final penetration depth, corresponding to the depth of the residual indentation on the crystal.

Image of FIG. 2.
FIG. 2.

Mechanical properties of the ZnO crystals. (a) The nanoindentation curves for -, -, and -plane ZnO taken with  = 3.0 mN. (b) The final penetration depth, , of the indentations on the various ZnO orientations as a function of the maximum applied load, .

Image of FIG. 3.
FIG. 3.

Low temperature CL (4 K) and PL (10 K) of the -plane oriented ZnO, normalized to the intensity of the two electron satellite of I (TES of I). Some of the transitions have been marked. Each orientation of ZnO exhibits similar luminescence.

Image of FIG. 4.
FIG. 4.

Low temperature CL and SE images of an indentation created using  = 3.0 mN on -plane ZnO. (a) SE image of the indentation region; (b) the CL spectrum taken at 4.4 K; and (c), (d), and (e) the monochromatic CL images taken at the energies indicated in (b). The width of the gray rectangles corresponds to the approximate range of energies shown in the CL images.

Image of FIG. 5.
FIG. 5.

Spot-mode CL taken near the indentation from Fig. 4 on -plane ZnO. (a) The CL spectra taken at 4.4 K, (b) CL image at 3.376 eV showing the location of the spots used in (a). The size of the spot-mode marks in Fig. 5(b) has the approximate area of the lowest expected spatial resolution of CL, ∼0.5 m.

Image of FIG. 6.
FIG. 6.

Low temperature CL and SE images of an indentation created using  = 5.0 mN on -plane ZnO. (a) SE image of the indentation area; (b) the CL spectrum taken at 4.4 K; and (c), (d), and (e) the monochromatic CL images taken at the energies indicated in (b). The width of the gray rectangles corresponds to the approximate range of energies shown in the CL images.

Image of FIG. 7.
FIG. 7.

Spot-mode CL taken near the indentation from Fig. 6 on -plane ZnO. (a) The CL spectra taken at 4.4 K, (b) CL image at 3.337 eV showing the location of the spots used in (a). The size of the spot-mode marks in Fig. 7(b) has the approximate area of the lowest expected spatial resolution of CL, ∼0.5 m.

Image of FIG. 8.
FIG. 8.

Low temperature CL and SE images of an indentation created using  = 3.9 mN on -plane ZnO. (a) SE image of the indentation area; (b) the CL spectrum taken at 4.4 K; and (c), (d), and (e) the monochromatic CL images taken at the energies indicated in (b). The width of the gray rectangles corresponds to the approximate range of energies shown in the CL images.

Image of FIG. 9.
FIG. 9.

Spot-mode CL taken near the indentation from Fig. 8 on -plane ZnO. (a) The CL spectra taken at 4.4 K, (b) CL image at 3.363 eV showing the location of the spots used in (a). The size of the spot-mode marks in Fig. 9(b) has the approximate area of the lowest expected spatial resolution of CL, ∼0.5 m.

Image of FIG. 10.
FIG. 10.

The orientation of the -directions relative to the applied load for each of the ZnO crystals. (a) The -plane oriented crystal, seen in -projection, (b) the -plane oriented crystal, seen in -projection, (c) the -plane oriented crystal, seen in -projection.

Image of FIG. 11.
FIG. 11.

Plan-view diagram of an indentation on -plane ZnO. The geometry of the indenter tip is shown in the center of the figure, indicating the spherical and cubic facets of the cono-spherical tip. The thicker, black arrows denote the direction of the in-plane stress introduced into the crystal. Basal plane slip is indicated by the vertical, dashed lines; the component of stress is relieved along this direction. The residual stress in the crystal is marked by the dotted arrows, leading to compressive strain where the arrows are parallel and tensile strain where the arrows are anti-parallel. This figure can be applied to the -plane indentation by switching the ⟨ ⟩ and ⟨ ⟩ directions marked in the center of the image.

Image of FIG. 12.
FIG. 12.

Plan-view diagram of an indentation on the -plane ZnO. The geometry of the indenter tip is shown in the center of the figure, indicating the spherical and cubic facets of the tip. Dislocation lines are generated along the -directions and overcompensate the compressive stress introduced by the tip, leading to tensile strain along these directions.

Tables

Generic image for table
Table I.

The maximum stress, , that can be supported by ZnO crystals as determined from nanoindentation curves, corresponding to a cono-spherical tip with  = 260 nm.

Generic image for table
Table II.

Summary of the results obtained from LT CL for nanoindentation on various orientations of ZnO.

Loading

Article metrics loading...

/content/aip/journal/jap/113/18/10.1063/1.4804309
2013-05-09
2014-04-19
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Strain-related optical properties of ZnO crystals due to nanoindentation on various surface orientations
http://aip.metastore.ingenta.com/content/aip/journal/jap/113/18/10.1063/1.4804309
10.1063/1.4804309
SEARCH_EXPAND_ITEM