کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7833693 1503523 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of sulfur related defects in graphene quantum dots for tuning photoluminescence and high quantum yield
ترجمه فارسی عنوان
بررسی نقصهای مرتبط با گوگرد در نقاط کوانتومی گرافن برای تنظیم فوتولومینسانس و عملکرد کوانتومی بالا
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
چکیده انگلیسی
This paper presents a comprehensive study of the impact of defects on quantum yield in doped graphene quantum dots by having sulfur containing compounds (S-GQDs). The facile and high yielding hydrothermal method was used to process the S-GQDs by selecting two different compounds such as conc. H2SO4 and MgSO4·7H2O containing sulfur. Initially, the synthesized samples were characterized by using High Resolution Transmission Electron Microscope (HRTEM), Raman Spectroscopy, Fourier Transform Infra-Red Spectroscopy (FT-IR), Thermogravimetric and Differential Thermal Analysis (TGA/DTA), UV-vis spectroscopy, and Photoluminescence (PL). HRTEM images suggest that the majority of the both samples were in the narrow range of 5-20 nm in diameter. Optical properties of the GQDs are altered as a result of S-doping with purple tunable PL at shorter wavelengths. As expected, by using the different excitation energy in PL, appearance of peak introduces additional energy levels between π and π* that provide alternative electron transition pathways. The most remarkable finding is that the fluorescence quantum yield (FL QY) of S-doped GQDs is higher than that of the reported doped GQDs. This clearly suggests that the defects states related to S modify the electron density, tailor the PL characteristics and improvements in quantum yield of the GQDs.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 449, 15 August 2018, Pages 363-370
نویسندگان
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