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: Effect of chemical composition on luminescence of thiol-stabilized CdTe nanocrystals | Nanoscale Res Lett 2007 2 230-234 DOI s11671-007-9052-x NANO EXPRESS Effect of chemical composition on luminescence of thiol-stabilized CdTe nanocrystals Norio Murase Nikolai Gaponik Horst Weller Published online 13 April 2007 to the authors 2007 Abstract Judicious selection of the amount of surfactant during synthesis enables a drastic increase in the photoluminescence efficiency of aqueous CdTe nanocrystals NCs stabilized by thioglycolic acid TGA . Elemental determination of the NCs was undertaken to identify the origin of this effect. The molar ratio of Te S to Cd approached unity when the optimum amount of TGA was used during synthesis whereas the number of S atoms originating from TGA molecules in one NC nm of diameter remained unchanged at 90 3. This indicates that the core lattice composition at the beginning of synthesis rather than the surface conditions affects the photoluminescence efficiency of the NCs even after prolonged refluxing. Keywords CdTe Nanocrystal Surfactant Thioglycolic acid Photoluminescence Efficiency Elemental determination Introduction Vast numbers of papers are currently being published in the field of emitting semiconductor nanocrystals NCs . The N. Murase El H. Weller Institute of Physical Chemistry University of Hamburg Grindelallee 117 20146 Hamburg Germany e-mail n-murase@ N. Murase Photonics Department National Institute of Advanced Industrial Science Technology AIST Ikeda Osaka 563-8577 Japan N. Gaponik Physical Chemistry Electrochemistry Technical University of Dresden Bergstr. 66b 01062 Dresden Germany synthesis of these NCs is either by an aqueous or organic solution method. CdTe 1 and CdSe 2 NCs are the most representative products for these two synthesis methods respectively. Initially the aqueous method had two drawbacks lower emission efficiency and a wider photoluminescence PL spectrum compared to the organic method along with their several advantages such as better reproducibility and easier .
