不同生长环境下砷化镓纳米颗粒的应变场模拟

对于埋嵌在薄膜材料中的纳米颗粒,在其生长过程中总是不可避免地伴随着应变场的产生,而这种应变场的分布能反映纳米颗粒的结构变化,纳米颗粒结构与它的物理性能有重要的关系.研究埋嵌在不同薄膜材料中的纳米颗粒生长过程中的应变场分布对于调控纳米颗粒的物理性能有着重要的意义.本文利用有限元算法分别计算了埋嵌在非晶氧化铝薄膜和非晶二氧化硅薄膜材料中的砷化镓纳米颗粒生长过程中的应变场分布.砷化镓纳米颗粒在以上两薄膜材料生长过程中都受到非均匀偏应变作用.对于埋嵌在氧化铝薄膜中的砷化镓纳米颗粒,其生长过程中,纳米颗粒内部受到的应变大于纳米颗粒表面受到的应变;而对于埋嵌在二氧化硅薄膜中的砷化镓纳米颗粒,纳米颗粒内部受到的应变小于纳米颗粒表面受到的应变.选择砷化镓纳米颗粒生长的薄膜材料可以调控纳米颗粒生长过程中的应变场分布,从而进一步调控纳米颗粒的晶格结构和形貌及其物理性能.

Simulation of Strain Distribution of GaAs Nanoparticles with Growth in Different Environment

The growth of nanoparticles embedded in a host matrix can lead to substantial strain. Strain can have much influence on the crystal growth and microstructure development of nanoparticles and thecorrelation of the physical properties of nanoparticles with their microstructures. To better understand and control the physical properties of GaAs nanoparticles, it is fundamentally necessary to study the strain distribution of nanoparticles embedded in different thin films.In this paper, the growth strain of GaAs nanoparticles embedded in Al₂O₃ and SiO₂ thin films were investigated. Finite element calculations clearly indicate that the GaAs nanoparticles incurs a net deviatoric strain in both amorphous Al₂O₃ and SiO₂ thin films. The compressive strain existing in the center of a GaAs nanoparticle embedded in Al₂O₃ thin film is stronger than that at the surface of the nanoparticle. In contrast, the compressive strain existing at the surface of a GaAs nanoparticle embedded in SiO₂ thin film is stronger than that in the center of the nanoparticle. It is possible to control the strain distribution of GaAs nanoparticles by embeding the GaAs nannoparticles in different thin films, which will futher influence the microstructures and morphologies of GaAs nanoparticles. Strain engineering is an effective tool for tailoring the properties of GaAs nanoparticles.