Year: 2021
Type: article
Abstract: Nitrogen (N) is a common element added to GaAs for band gap engineering and strain compensation. However, detection of small amounts of N is difficult for electron microscopy as well as for other chemical analysis techniques. In this work, N in GaAs is examined by using different transmission electron microscopy (TEM) techniques. While both dark-field TEM imaging using the composition sensitive (002) reflections and selected area diffraction reveal a significant difference between the doped thin-film and the GaAs substrate, spectroscopy techniques such as electron energy loss and energy dispersive X-ray spectroscopy are not able to detect N. To quantify the N content, quantitative convergent beam electron diffraction (QCBED) is used, which gives a direct evidence of N substitution and As vacancies. The measurements are enabled by the electron energy-filtered scanning CBED technique. These results demonstrate a sensitive method for composition analysis based on quantitative electron diffraction.
Source: Ultramicroscopy
Authors: Maryam Vatanparast, Yu-Tsun Shao, Mohana Rajpalke, Bjørn-Ove Fimland, Turid Reenaas, Randi Holmestad, Per Erik Vullum, Jian Min Zuo
Language: English
Subfield: Structural Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,050
Awards: G3934138050, G5650140596, G758829067
OpenAlex ID: W3160536874