کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5466689 | 1518297 | 2017 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Bandgap measurement of high refractive index materials by off-axis EELS
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In the present work Cs aberration corrected and monochromated scanning transmission electron microscopy electron energy loss spectroscopy (STEM-EELS) has been used to explore experimental set-ups that allow bandgaps of high refractive index materials to be determined. Semi-convergence and -collection angles in the µrad range were combined with off-axis or dark field EELS to avoid relativistic losses and guided light modes in the low loss range to contribute to the acquired EEL spectra. Off-axis EELS further supressed the zero loss peak and the tail of the zero loss peak. The bandgap of several GaAs-based materials were successfully determined by simple regression analyses of the background subtracted EEL spectra. The presented set-up does not require that the acceleration voltage is set to below the Äerenkov limit and can be applied over the entire acceleration voltage range of modern TEMs and for a wide range of specimen thicknesses.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ultramicroscopy - Volume 182, November 2017, Pages 92-98
Journal: Ultramicroscopy - Volume 182, November 2017, Pages 92-98
نویسندگان
Maryam Vatanparast, Ricardo Egoavil, Turid W. Reenaas, Johan Verbeeck, Randi Holmestad, Per Erik Vullum,