Papers by Keyword: Silicon Oxide Defect

Abstract: Porous silicon (p-Si) is a well-known silicon based material that can emit visible light at room temperature. The radiative recombination that originated from quantum confinement effect shows photoluminescence (PL) in red, while the defect on silicon oxide at the surface of p-Si shows in blue-green region. Porous silicon can be synthesized through two methods; wet-etching and electrochemical anodization using hydrofluoric acid as the main electrolyte. The electrochemical anodization is more favorable due to faster etching rate at the surface than the conventional wet-etching method. The objective of this research is to show that both of porous silicons can be synthesized using the same main electrolyte but by varying the reaction environment during anodization/etching process. Here, we shows the wet-etching method that enhanced by polarization concentration will produce porous silicon with silicon oxide defects by means blue-green emission, while direct electrochemical anodization will produce samples that emit red PL signal. The effect of introducing KOH into the electrolyte was also studied in the case of enhanced-wet-etching method. Surface morphology of porous silicon and their photoluminescence were observed by Scanning Electron Microscope and PL spectroscopy, respectively.

Abstract: The effect of preparation conditions and annealing treatment on Si-rich-SiOx layers was investigated. It was observed that oxygen plays important role in the creation of light-emitting centres. It was found that the emission in the green-orange spectral range is connected with silicon oxide defects which contain dangling bonds. At the same time PL band in the infrared spectral range is caused by recombination of carriers in amorphous silicon or nanocrystalline one. It is shown that modification of defect content under various treatments gives the possibility to control the emission properties of the layers.