کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1792698 1023654 2010 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Vacancy defects in bulk ammonothermal GaN crystals
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Vacancy defects in bulk ammonothermal GaN crystals
چکیده انگلیسی

We have applied positron annihilation spectroscopy to study in-grown vacancy defects in bulk GaN crystals grown by the ammonothermal method. We observe a high concentration of Ga vacancy related defects in n-type samples in spite of the low growth temperature, suggesting that oxygen impurities promote the formation of vacancies also through other mechanisms than a mere reduction of thermodynamical formation enthalpy. On the other hand, no positron trapping at vacancy defects is observed in Mg-doped p-type samples, as expected when the Fermi level is close to the valence band and intrinsic defects are dominantly positively charged. Annealing of the samples at temperatures well above the growth temperature is found to change significantly the defect structure of the material.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Crystal Growth - Volume 312, Issue 18, 1 September 2010, Pages 2620–2623
نویسندگان
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