Wu Mingjian, Hanke Michael, Luna Esperanza, Puustinen Janne, Guina Mircea, Trampert Achim
Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin, Germany. Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FI-33101, Tampere, Finland.
Nanotechnology. 2015 Oct 23;26(42):425701. doi: 10.1088/0957-4484/26/42/425701. Epub 2015 Sep 30.
The ability to characterize a structure into the finest details in a quantitative manner is a key issue to understanding and controlling nanoscale phase separation in novel nanomaterials. In this work, we consider the detectability of lateral composition modulation (LCM), a type of nanoscale phase separation in GaAs(1-x)Bix epilayers, by x-ray diffraction (XRD). We show that the satellite peaks due to LCM are hardly detectable in reasonable time with a lab x-ray diffractometer for GaAs(1-x)Bix samples with an average x up to 25% and relative modulation up to 50%. This is in contrast to LCM reported in other III-V combinations, where the intensity of the satellite peak is relatively high and can be easily detected. Our theoretical considerations are complemented experimentally using highly brilliant synchrotron radiation. The results are in good agreement with the predictions. This work provides a guideline for the systematic characterization of LCM in zincblende III-V semiconductor epilayers and points to the critical role of quantitative characterization of nanoscale phase separation.
以定量方式将结构表征到最精细的细节，是理解和控制新型纳米材料中纳米级相分离的关键问题。在这项工作中，我们考虑通过X射线衍射（XRD）检测横向成分调制（LCM），这是一种在GaAs(1-x)Bix外延层中的纳米级相分离类型。我们表明，对于平均x高达25%且相对调制高达50%的GaAs(1-x)Bix样品，使用实验室X射线衍射仪在合理时间内几乎无法检测到由LCM引起的卫星峰。这与其他III-V族组合中报道的LCM形成对比，在其他组合中卫星峰的强度相对较高且易于检测。我们的理论考虑通过使用高亮度同步辐射进行了实验补充。结果与预测结果吻合良好。这项工作为闪锌矿III-V族半导体外延层中LCM的系统表征提供了指导，并指出了纳米级相分离定量表征的关键作用。
