Characterization of Ⅲ-nitrides nano-patterns fabricated by atomic force microscopy and by Characterization of semiconductors by scanning probe microscopy
碩士 === 國立臺灣海洋大學 === 光電科學研究所 === 95 === Abstract The thesis describes the characterization of the luminescent property of oxidation-patterned Ⅲ-N light emitting diodes (LEDs) and the characterization of sulfidated Ⅱ-Ⅵ semiconductors by atomic force microscopy (AFM) . First, nano-scale oxidation patte...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2007
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| Online Access: | http://ndltd.ncl.edu.tw/handle/07931983803185696104 |
| Summary: | 碩士 === 國立臺灣海洋大學 === 光電科學研究所 === 95 === Abstract
The thesis describes the characterization of the luminescent property of oxidation-patterned Ⅲ-N light emitting diodes (LEDs) and the characterization of sulfidated Ⅱ-Ⅵ semiconductors by atomic force microscopy (AFM) .
First, nano-scale oxidation patterns were made by AFM using the anodic oxidation. The nano-scale oxidation spot arrays with different density were made in a 20μm × 20μm area . The photoluminescence (PL) intensity of the patterned Ⅲ-N LEDs was found to increase with the increasing density of oxidation area . The increment in PL intensity was as high as 1.9 times under our experimental conditions. It was also found that the PL intensity could be further enhanced by removing the oxidation patterns. The highest increment in PL intensity was 3.2 times to that of the as grown sample. Note that the AFM oxidation was found to have limited effect in depth (<100nm) and have no additional changes in the radiative mechanisms of the oxidated samples. Our work has demonstrate that AFM oxidation can provide a local, nano-scale and simple method to enhance the extraction of emitting light from Ⅲ-N LEDs effectively. Our results are believed to be useful for the development and applications of nano-photonics technology.
In the second part of the thesis, we study the effect of sulfidation on the electrical and optical properties of ZnO films by Scanning Kelvin Probe Microscopy (SKPM) and PL measurements. The SKPM measured the contact potentials of the sample and the results indicated the free electron density can be reduced by sulfidation of ZnO. The reduction in the free electron concentration inferred the passivation of oxygen-related defects. It was found that the sulfidation of ZnO could possiblely eliminate the effects of defect-related radiative recombination centers and its related non-radiative recombination centers by passivation of oxygen-related defects.
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