tailieunhanh - Báo cáo hóa học: " Formation of PbSe/CdSe Core/Shell Nanocrystals for Stable Near-Infrared High Photoluminescence Emission"

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: Formation of PbSe/CdSe Core/Shell Nanocrystals for Stable Near-Infrared High Photoluminescence Emission | Nanoscale Res Lett 2010 5 1279-1283 DOI s11671-010-9637-7 NANO EXPRESS Formation of PbSe CdSe Core Shell Nanocrystals for Stable Near-Infrared High Photoluminescence Emission Yu Zhang Quanqin Dai Xinbi Li Qingzhou Cui Zhiyong Gu Bo Zou Yiding Wang William W. Yu Received 6 April 2010 Accepted 5 May 2010 Published online 1 June 2010 The Author s 2010. This article is published with open access at Abstract PbSe CdSe core shell nanocrystals with quantum yield of 70 were obtained by the successive ion layer adsorption and reaction technology in solution. The thickness of the CdSe shell was exactly controlled. A series of spectral red shifts with the CdSe shell growth were observed which was attributed to the combined effect of the surface polarization and the expansion of carriers wavefunctions. The stability of PbSe nanocrystals was tremendously improved with CdSe shells. Keywords PbSe CdSe Core-shell Near infrared Emission Nanocrystals The authors Yu Zhang and Quanqin Dai contributed equally to this work. Y. Zhang Q. Dai Y. Wang W. W. Yu State Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering Jilin University Changchun 130012 China e-mail wangyiding47@ W. W. Yu e-mail wyu6000@ Y. Zhang X. Li W. W. Yu Department of Chemistry and Biochemistry Worcester Polytechnic Institute Worcester MA 01609 USA Q. Cui Z. Gu Department of Chemistry Engineering University of Massachusetts Lowell Lowell MA 01854 USA B. Zou State Key Laboratory of Superhard Materials Jilin University Changchun 130012 China Colloidal IV-VI semiconductor nanocrystals also known as quantum dots QDs are of increasing potential applications in telecommunication photoelectronic device and biomedical labeling 1 2 etc. PbSe QDs are important materials because of the strong confinement effect due to their large Bohr radius and the small band gap in near infrared region. Several approaches have been developed to prepare PbSe QDs