tailieunhanh - Báo cáo hóa học: " Combined plasma gas-phase synthesis and colloidal processing of InP/ZnS core/shell nanocrystals"

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: Combined plasma gas-phase synthesis and colloidal processing of InP/ZnS core/shell nanocrystals | Gresback et al. Nanoscale Research Letters 2011 6 68 http content 6 1 68 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Combined plasma gas-phase synthesis and colloidal processing of InP ZnS core shell nanocrystals 12 2 1 Ryan Gresback Ryan Hue Wayne L Gladfelter Uwe R Kortshagen Abstract Indium phosphide nanocrystals InP NCs with diameters ranging from 2 to 5 nm were synthesized with a scalable flow-through nonthermal plasma process at a rate ranging from 10 to 40 mg h. The NC size is controlled through the plasma operating parameters with the residence time of the gas in the plasma region strongly influencing the NC size. The NC size distribution is narrow with the standard deviation being less than 20 of the mean NC size. Zinc sulfide ZnS shells were grown around the plasma-synthesized InP NCs in a liquid phase reaction. Photoluminescence with quantum yields as high as 15 were observed for the InP ZnS core-shell NCs. Introduction Over the last two decades semiconductor nanocrystals NCs have attracted significant attention because of their various unique properties. Semiconductor NCs provide size-tunable optical and electrical properties based on quantum confinement of charge carriers within them high surface-to-volume ratios and other attributes that have led to the development of a new generation of materials and devices 1 2 . A significant amount of study has focused on compound semiconductor NCs of the II-VI and IV-VI systems because of the relative ease of synthesizing high quality materials using colloidal techniques 3 4 . While synthesis and surface functionalization methods for these NC materials are well established and NCs have shown impressive optical and electronic properties there exists considerable interest to produce systems consisting of NCs of other materials whose constituent elements pose less of an environmental concern which are more radiation resistant and less prone to .