کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5404308 | 1392776 | 2006 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Surface states and its influence on luminescence in ZnS nanocrystallite
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
In this pape,r the influence of surface effects on the self-activated (SA) luminescence in ZnS nanoparticles prepared by the wet-chemical method is presented. It is observed that the luminescence of SA decreases dramatically by rinsing with methanol. In the rinsed sample, the luminescence of SA increases more by ultraviolet (UV) light irradiation. To clarify its origin, the Raman spectra and electron paramagnetic resonance (EPR) are studied. The results demonstrate that the vibrational modes assigned to organic functional groups of -OH and -COO and -CH3 decreases remarkably by rinsing, while the EPR signal originated from the unpaired electrons of some transition metal impurity ions including Mn2+ increases. It is suggested that the SA centers prefer to occupy the sites near the surface and that the donor of SA emission may be partly related to the organic functional groups of -OH and -COO adsorbed on the surface. The surface-dangling bonds caused by unpaired electrons of some transition metal impurity ions play a role of surface states, leading to the quenching of the SA emissions. The organic functional groups chemically combine with these surface-dangling bonds leading to the decrease in surface states and surface nonradiative relaxation channels and to the increase in the SA emissions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 118, Issue 2, June 2006, Pages 251-256
Journal: Journal of Luminescence - Volume 118, Issue 2, June 2006, Pages 251-256
نویسندگان
Xiaobo Zhang, Hongwei Song, Lixin Yu, Tie Wang, Xinguang Ren Xinguang Ren, Xianggui Kong, Yuhua Xie, Xiaojun Wang,