Paul-Drude-Institute for Solid State Electronics, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
Nanotechnology. 2010 Jun 18;21(24):245705. doi: 10.1088/0957-4484/21/24/245705. Epub 2010 May 20.
Strain relaxation mechanisms occurring during self-induced growth of nitride nanowires are investigated by in situ reflection high-energy electron diffraction and ex situ high-resolution transmission electron microscopy. Epitaxial GaN nanowires nucleate on an AlN buffer layer under highly nitrogen-rich conditions via the initial formation of coherently strained three-dimensional islands according to the Volmer-Weber growth mechanism. The epitaxial strain relief in these islands occurs by two different processes. Initially, strain is elastically relieved via several shape transitions. Subsequently, plastic relaxation takes place through the formation of a misfit dislocation at the GaN/AlN interface. At the same time, a final shape transition to fully relaxed nanowires occurs.
通过原位反射高能电子衍射和非原位高分辨率透射电子显微镜研究了氮化物纳米线自诱导生长过程中应变弛豫的机制。在富氮条件下，通过最初形成与 AlN 衬底共格应变的三维岛，根据 Volmer-Weber 生长机制，在 AlN 缓冲层上形核外延 GaN 纳米线。这些岛中的外延应变弛豫通过两种不同的过程发生。最初，应变通过几个形状转变弹性弛豫。随后，通过在 GaN/AlN 界面形成位错而发生塑性弛豫。同时，通过最终的形状转变，形成完全弛豫的纳米线。
