This paper discusses the optical properties of colloidal CdSe/CdTe, CdTe/CdSe, and CdTe/CdS heterostructures synthesized by growing a shell on CdSe and CdTe nanocrystals. The extinction coefficients of the first exciton absorption band and the extinction coefficients at 400 nm are determined as a function of the amount of shell material added during the growth of the heterostructures. It is shown that the resulting heterostructures have extinction coefficients 1–2 orders of magnitude greater than the initial cores: up to 0.3×10<sup>7</sup>cm<sup>−1</sup>M<sup>−1</sup> in the case of CdTe/CdS and CdTe/CdSe and up to 1.6×10<sup>7</sup>cm<sup>−1</sup>M<sup>−1</sup> in the case of CdSe/CdTe. It is shown that the luminescence wavelength in the 550–950-nm range can be controlled by varying the shell size for CdSe/CdTe heterostructures.
© 2011 OSAPDF Article