Self-assembled germanium nano-structures by laser-assisted oxidation
Huang Wei-Qi (黄伟其)acd, Liu Shi-Rong (刘世荣)b
a Department of Physics, Guizhou University, Guiyang 550026, Chinab Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550003, Chinac Department of Physics, Guizhou Educational College, Guiyang 550003, China; d Optoelectronics Physics Lab, Guizhou University, Guiyang 550026, China
Abstract The investigation on the oxidation behaviour of Si$_{1-x}$Ge$_{x}$ alloys ($x$=0.05, 0.15, and 0.25) is carried out. It is found for the first time that on the oxide film a germanium nano-cap with a thickness of 1.8--2.8nm and a few Ge nanoparticles with diameters ranging from 5.5 nm to 10 nm are formed by the low-temperature laser-assisted dry oxidation of Si$_{1 - x}$Ge$_{x}$ substrate. A new scanning method on the decline cross-section of the multiple-layer sample is adopted to measure the layer thickness and the composition. Some new peaks in photoluminescence (PL) spectra are discovered, which could be related to the nano-cap and the nano-particles of germanium. A suitable model and several new calculating formulae with the unrestricted Hartree--Fock--Roothaan (UHFR) method and quantum confinement analysis are proposed to interpret the PL spectra and the nano-structure mechanism in the oxide.
Received: 20 April 2005
Revised: 08 October 2005
Accepted manuscript online:
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
