Orientation-controlled growth and optical properties of diverse Ag nanoparticles on Si(100) and Si(111) wafers

• Published in: Nanotechnology 2013-02, Vol.24 (4), p.045601-045601
• Main Authors: Wang, Ruey-Chi, Lin, Yu-Xian, Huang, Michael R S, Chao, Chien-Yang
• Format: Article
• Language: English
• Subjects: Adsorption; Chemical synthesis methods; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystallization - methods; Exact sciences and technology; Fullerenes and related materials; Infrared and raman spectra and scattering; Light; Materials science; Materials Testing; Metal Nanoparticles - chemistry; Metal Nanoparticles - radiation effects; Methods of nanofabrication; Molecular Conformation - radiation effects; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optoelectronic devices; Other topics in nanoscale materials and structures; Particle Size; Physics; Planes; Refractometry; Scattering, Radiation; Silicon; Silicon - chemistry; Silicon substrates; Silver; Silver - chemistry; Silver - radiation effects; Structure of solids and liquids; crystallography; Surface Properties - radiation effects
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/24/4/045601

Well-controlled growth of Ag nanoparticles (NPs) on Si substrates is important for next generation Si-based optoelectronic devices, but only randomly oriented Ag NPs have been previously reported. In this work, well-oriented Ag NPs with regular shapes are pseudomorphically grown on Si(100) and Si(111) substrates with crystallographic relationships of {100}〈010〉Ag {100}〈010〉Si and {111}〈110〉Ag {111}〈110〉Si, respectively. From a cross-sectional image, the Ag NPs on Si(100) substrates penetrate into Si and generate an inverted pyramid-like structure terminated by {111} planes embedded in Si substrates. In contrast, the Ag NPs on Si(111) substrates show flat morphology with the top plane terminated by Ag {111}. The Si underneath Ag NPs was not penetrated by Ag and a SiO2 layer was formed between Ag and Si. Photoluminescence spectra of the Ag NPs show ultraviolet emissions centered in the 340-343 nm range. The 〈111〉-oriented Ag particles show stronger emissions with an extra peak at 343 nm compared with 〈100〉-oriented Ag NPs. Raman spectra show that the 〈100〉- and 〈111〉-oriented Ag NPs can enhance the peak intensity of Si(100) and Si(111) by 45.3% and 32.5%, respectively. The orientation-controlled Ag NPs with anisotropic optical properties are promising materials for Si-based optoelectronics.