Effects of annealing temperature on shape transformation and optical properties of germanium quantum dots

作     者：Alireza Samavati Z.Othaman S.K.Ghoshal M.K.Mustafa 

作者机构：Ibn Sina Institute for Fundamental Science StudiesUniversiti Teknologi Malaysia Advanced Optical Material Research GroupDepartment of PhysicsFaculty of ScienceUniversiti Teknologi Malaysia Faculty of Science Technology and Human DevelopmentUniversiti Tun Hussein Onn Malaysia 

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

年 卷 期：2015年第24卷第2期

页      面：459-466页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070205[理学-凝聚态物理] 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）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：supported by Ibnu Sina Institute for Fundamental Science Study,Universiti Teknologi Malaysia through Vote Q.J130000.2526.02H94,05 Postdoctoral Research Grant 

主　　题：Ge QDs sputtering surface morphology optical properties 

摘      要：The influences of thermal annealing on the structural and optical features of radio frequency（rf） magnetron sputtered self-assembled Ge quantum dots（QDs） on Si（100） are *** oriented structures of Ge along the（220） and（111） directions together with peak shift and reduced strain（4.9%to 2.7%） due to post-annealing at 650 ℃ are discerned from x-ray differaction（XRD） *** force microscopy（AFM） images for both pre-annealed and post-annealed（650 ℃） samples reveal pyramidal-shaped QDs（density - 0.26×10^11 cm^-2） and dome-shape morphologies with relatively high density - 0.92×10^11 cm^-2,*** shape transformation is attributed to the mechanism of inter-diffusion of Si in Ge interfacial intermixing and strain *** annealing temperature assisted QDs structural evolution is explained using the theory of nucleation and growth kinetics where free energy minimization plays a pivotal *** observed red-shift - 0.05 eV in addition to the narrowing of the photoluminescence peaks results from thermal annealing,and is related to the effect of quantum ***,the appearance of a blue-violet emission peak is ascribed to the recombination of the localized electrons in the Ge-QDs/SiO2 or GeOx and holes in the ground state of Ge *** spectra of both samples exhibit an intense Ge-Ge optical phonon mode which shifts towards higher frequency compared with those of the bulk *** experimental Raman profile is fitted to the models of phonon confinement and size distribution combined with phonon confinement to estimate the mean dot sizes.A correlation between thermal annealing and modifications of the structural and optical behavior of Ge QDs is *** growth of Ge QDs with superior properties suitable for optoelectronic applications is demonstrated.