tailieunhanh - Báo cáo hóa học: " Facile Phosphine-Free Synthesis of CdSe/ZnS Core/Shell Nanocrystals Without Precursor Injection"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Facile Phosphine-Free Synthesis of CdSe/ZnS Core/Shell Nanocrystals Without Precursor Injection | Nanoscale Res Lett 2008 3 213-220 DOI s11671-008-9139-z NANO EXPRESS Facile Phosphine-Free Synthesis of CdSe ZnS Core Shell Nanocrystals Without Precursor Injection Chang-Qing Zhu Peng Wang Xin Wang Yan Li Received 31 March 2008 Accepted 3 June 2008 Published online to the authors 2008 Abstract A new simple method for synthesis of core shell CdSe ZnS nanocrystals NCs is present. By adapting the use of cadmium stearate oleylamine and paraffin liquid to a non-injection synthesis and by applying a subsequent ZnS shelling procedure to CdSe NCs cores using Zinc acetate dihydrate and sulfur powder luminescent CdSe ZnS NCs with quantum yields of up to 36 FWHM 42-43 nm were obtained. A seeding-growth technique was first applied to the controlled synthesis of ZnS shell. This method has several attractive features such as the usage of low-cost green and environmentally friendlier reagents and elimination of the need for air-sensitive toxic and expensive phosphines solvent. Furthermore due to one-pot synthetic route for CdSe ZnS NCs the approach presented herein is accessible to a mass production of these NCs. Keywords Phosphine-free CdSe ZnS One-pot Non-injection Introduction Colloidal semiconductor nanocrystals NCs are of great interest for both fundamental studies 1 2 and technical applications such as light-emitting devices 3 4 lasers 5 6 and fluorescent labels 7-9 . CdSe nanocrystals have become the most extensively investigated NCs due to their size-dependent photoluminescence tunable across the visible spectrum 10 . Recently much experimental work has . Zhu H P. Wang X. Wang Y. Li College of Chemistry and Materials Science Anhui Key Laboratory of Functional Molecular Solid Anhui Normal University Wuhu 241000 Peoples Republic of China e-mail zhucq@ 24 June 2008 been devoted to molecular surface modification to improve the luminescence efficiency 11 12 and photostability of the NCs or to develop a reliable processing chemistry 13 14 . To .