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Morphology control and optical properties of SiGe nanostructures grown on glass substrate.

Chang HK, Lee SC - Nanoscale Res Lett (2012)

Bottom Line: In this study, SiGe nanostructures with several kinds of configurations have been synthesized through a chemical vapor deposition process.By controlling growth conditions, different SiGe nanostructures can be easily tuned.The control of the SiGe morphology on nanoscale provides a convenient route to produce diverse SiGe nanostructures and creates new opportunities to realize the integration of future devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, 10617, Taiwan. sclee@cc.ee.ntu.edu.tw.

ABSTRACT
With the rapid progress of nanotechnology, nanostructures with different morphologies have been realized, which may be very promising to enhance the performance of semiconductor devices. In this study, SiGe nanostructures with several kinds of configurations have been synthesized through a chemical vapor deposition process. By controlling growth conditions, different SiGe nanostructures can be easily tuned. Structures and compositions of the nanostructures were determined by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The optical properties of various SiGe nanostructures revealed some dependence with their morphologies, which may be suitable for solar cell applications. The control of the SiGe morphology on nanoscale provides a convenient route to produce diverse SiGe nanostructures and creates new opportunities to realize the integration of future devices.

No MeSH data available.


Related in: MedlinePlus

SEM image and EDX data. (a) SEM image of nanorods grown at 438°C and (b) corresponding EDX results.
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Figure 2: SEM image and EDX data. (a) SEM image of nanorods grown at 438°C and (b) corresponding EDX results.

Mentions: Due to the relatively lower eutectic temperature of Au/Si and Au/Ge alloys (approximately 363°C for Au/Si and 361°C for Au/Ge), gold as catalyst is particularly suitable for one-dimensional SiGe nanostructure growth. In order to achieve a higher growth rate, the experiments were started at 405°C. Figure 1a shows a scanning electron microscopy (SEM) image of SiGe nanorods grown at 405°C. The as-grown samples are randomly oriented with lengths shorter than 5 μm. The EDX analysis shows that the element Ge in SiGe nanorods has a higher concentration compared to the element Si, as demonstrated in Figure 1b. The signals of aluminium, oxygen, and calcium in this EDX data are mainly from the glass substrate. When the growth temperature is heated to 438°C, however, the yields of the SiGe nanorods are totally decreased, as can be seen from Figure 2a. Besides, the lengths of the nanorods are shorter than 2 μm even though the growth time is the same with the sample grown at 405°C. From EDX data, as shown in Figure 2b, we found that the Ge concentration at this temperature is higher than Si as well. If we move the growth temperature to 462°C, the yields will be highly improved, but some instability on the surfaces of the SiGe nanostructures will occur. This instability results in a bead-like structure, which means wavy sidewalls are along individual SiGe nanowires. This phenomenon has been observed before in Si whisker growth via the VLS method and was attributed to a self-oscillation mechanism [9].


Morphology control and optical properties of SiGe nanostructures grown on glass substrate.

Chang HK, Lee SC - Nanoscale Res Lett (2012)

SEM image and EDX data. (a) SEM image of nanorods grown at 438°C and (b) corresponding EDX results.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3298705&req=5

Figure 2: SEM image and EDX data. (a) SEM image of nanorods grown at 438°C and (b) corresponding EDX results.
Mentions: Due to the relatively lower eutectic temperature of Au/Si and Au/Ge alloys (approximately 363°C for Au/Si and 361°C for Au/Ge), gold as catalyst is particularly suitable for one-dimensional SiGe nanostructure growth. In order to achieve a higher growth rate, the experiments were started at 405°C. Figure 1a shows a scanning electron microscopy (SEM) image of SiGe nanorods grown at 405°C. The as-grown samples are randomly oriented with lengths shorter than 5 μm. The EDX analysis shows that the element Ge in SiGe nanorods has a higher concentration compared to the element Si, as demonstrated in Figure 1b. The signals of aluminium, oxygen, and calcium in this EDX data are mainly from the glass substrate. When the growth temperature is heated to 438°C, however, the yields of the SiGe nanorods are totally decreased, as can be seen from Figure 2a. Besides, the lengths of the nanorods are shorter than 2 μm even though the growth time is the same with the sample grown at 405°C. From EDX data, as shown in Figure 2b, we found that the Ge concentration at this temperature is higher than Si as well. If we move the growth temperature to 462°C, the yields will be highly improved, but some instability on the surfaces of the SiGe nanostructures will occur. This instability results in a bead-like structure, which means wavy sidewalls are along individual SiGe nanowires. This phenomenon has been observed before in Si whisker growth via the VLS method and was attributed to a self-oscillation mechanism [9].

Bottom Line: In this study, SiGe nanostructures with several kinds of configurations have been synthesized through a chemical vapor deposition process.By controlling growth conditions, different SiGe nanostructures can be easily tuned.The control of the SiGe morphology on nanoscale provides a convenient route to produce diverse SiGe nanostructures and creates new opportunities to realize the integration of future devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, 10617, Taiwan. sclee@cc.ee.ntu.edu.tw.

ABSTRACT
With the rapid progress of nanotechnology, nanostructures with different morphologies have been realized, which may be very promising to enhance the performance of semiconductor devices. In this study, SiGe nanostructures with several kinds of configurations have been synthesized through a chemical vapor deposition process. By controlling growth conditions, different SiGe nanostructures can be easily tuned. Structures and compositions of the nanostructures were determined by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The optical properties of various SiGe nanostructures revealed some dependence with their morphologies, which may be suitable for solar cell applications. The control of the SiGe morphology on nanoscale provides a convenient route to produce diverse SiGe nanostructures and creates new opportunities to realize the integration of future devices.

No MeSH data available.


Related in: MedlinePlus