Germanium nanoislands grown by radio frequency magnetron sputtering: Annealing time dependent surface morphology and photoluminescence

作     者：Alireza Samavati Z.Othaman S.K.Ghoshal R.J.Amjad 

作者机构：Ibn Sina Institute for Fundamental Science StudiesUniversiti Teknologi Malaysia Advanced Optical Material Research GroupDepartment of PhysicsFaculty of ScienceUniversiti Teknologi Malaysia 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2013年第22卷第9期

页      面：600-604页

核心收录：

学科分类：08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the International Doctoral Fellowship (IDF)  Ibnu Sina Institute for Fundamental Science Study and research grants of MoHE GUP. Vot No. 02H94 and 07J80 

主　　题：germanium nanoislands radio frequency magnetron sputtering photoluminescence surface mor-phology 

摘      要：Structural and optical properties of ～ 20 nm Ge nanoislands grown on Si（100） by radio frequency （rI） magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature of 600 ℃ for 30 s, 90 s, and 120 s are performed to examine the influence of annealing time on the surface morphology and photoluminescence properties. X-ray diffraction spectra reveal prominent Ge and GeO2 peaks highly sensitive to the annealing time. Atomic force microscope micrographs of the as-grown sample show pyramidal nanoislands with relatively high-density （～ 10^11 cm^-2）. The nanoislands become dome-shaped upon annealing through a coarsening process mediated by Oswald ripening. The room temperature photoluminescence peaks for both as-grown （～ 3.29 eV） and annealed （～ 3.19 eV） samples consist of high intensity and broad emission, attributed to the effect of quantum confinement. The red shift （～ 0.10 eV） of the emission peak is attributed to the change in the size of the Ge nanoislands caused by annealing. Our easy fabrication method may contribute to the development of Ge nanostructure-based optoelectronics.