Molecular dynamics simulations and photoluminescence measurements of annealed ZnO surfaces

التفاصيل البيبلوغرافية
العنوان: Molecular dynamics simulations and photoluminescence measurements of annealed ZnO surfaces
المؤلفون: Min, Tjun Kit, Yoon, Tiem Leong, Ling, Chuo Ann, Mahmud, Shahrom, Lim, Thong Leng, Saw, Kim Guan
سنة النشر: 2016
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Materials Science
الوصف: The effect of thermal annealing on wurtzite ZnO, terminated by two surfaces, (0 0 0 $\bar 1$) (which is oxygen-terminated) and (0 0 0 1) (which is Zn-terminated), is investigated via molecular dynamics simulation using reactive force field (ReaxFF). As a result of annealing at a threshold temperature range of 700~K $ < T_{\mbox{\small t}} \leq 800$~K, surface oxygen atoms begin to sublimate from the (0 0 0 $\bar 1$) surface, while no atom leaves the (0 0 0 1) surface. The ratio of oxygen leaving the surface increases with temperature $T$ (for $T \geq T_{\mbox{\small t}}$). The relative luminescence intensity of the secondary peak in the photoluminescence (PL) spectra, interpreted as a measurement of amount of vacancies on the sample surfaces, qualitatively agrees with the threshold behavior as found in the MD simulations. Our simulations have also revealed the formation of oxygen dimers on the surface and evolution of partial charge distribution during the annealing process. Our MD simulation based on the ReaxFF is consistent with experimental observations.
Comment: 26 pages, 11 figures. Manuscript submitted to Physica E
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/1611.02170
رقم الانضمام: edsarx.1611.02170
قاعدة البيانات: arXiv