Samavati Alireza, Othaman Zulkafli, Dabagh Shadab, Ghoshal Sib Krishna
J Nanosci Nanotechnol. 2014 Jul;14(7):5266-71. doi: 10.1166/jnn.2014.8710.
Controlled growth and characterization of germanium (Ge) and silicon (Si) nanostructure are the key issues for optoelectronic device fabrication. The role of post-annealing on the structural and optical properties of radio frequency (rf) magnetron sputtering grown of Ge and Si quantum dots (QDs) deposited on Si(100) substrate is studied. Atomic force microscopy confirmed the formation of Si and Ge QDs with estimated sizes lower than -17 nm and -14 nm respectively. The X-ray diffraction analysis revealed the formation of Si and Ge QDs accompanied by SiO2 with estimated sizes of -5 and -7 nm for post-annealed Si and pre-annealed Ge QDs respectively. The room temperature photoluminescence spectra for Ge and Si demonstrated an emission peak at 3.20 and 2.72 eV respectively, which are attributed to the electron and hole recombination within QDs. A shift in the PL peak is observed through annealing which is ascribable to the changes in size of QDs and quantum confinement effect. The thermal annealing at 600 degrees C is found to play an important role in controlling the shape, number density, root mean square (rms) roughness and the energy shift of the luminescence band for both Si and Ge QDs. The influence of annealing on growth morphology for Ge QDs is appeared to be stronger than Si.
锗（Ge）和硅（Si）纳米结构的可控生长与表征是光电器件制造的关键问题。研究了退火后处理对沉积在Si(100)衬底上的通过射频（rf）磁控溅射生长的Ge和Si量子点（QD）的结构和光学性质的作用。原子力显微镜证实形成了Si和Ge量子点，估计尺寸分别小于-17 nm和-14 nm。X射线衍射分析表明，对于退火后的Si量子点和预退火的Ge量子点，分别形成了尺寸估计为-5 nm和-7 nm的伴随SiO2的Si和Ge量子点。Ge和Si在室温下的光致发光光谱分别在3.20和2.72 eV处显示出发射峰，这归因于量子点内的电子和空穴复合。通过退火观察到PL峰的位移，这归因于量子点尺寸的变化和量子限制效应。发现在600℃下的热退火在控制Si和Ge量子点的形状、数密度、均方根（rms）粗糙度和发光带的能量位移方面起着重要作用。退火对Ge量子点生长形态的影响似乎比Si更强。
