1.School of Materials Science and Engineering,Shanghai Institute of Technology;2.Key Laboratory of Infrared Imaging Materials and Devices,Shanghai Institute of Technical Physics,Chinese Academy of Sciences
The ion exchange is one of the important methods to realize the band gap regulation of alloy quantum dots. In this paper, monodispersed CdTe quantum dots are synthesized by soft chemical method. Meanwhile, mercury cadmium telluride (HgxCd1-xTe) quantum dots with the quasi continuous visible to near-infrared spectrum are prepared by ion exchange adjusting the concentration of Hg2+. The variable temperature photoluminescence and self-absorption characteristics of near-infrared Hg0.33Cd0.67Te quantum dots are deeply analyzed. The results indicate that the fluorescence intensity of HgxCd1-xTe quantum dots decreases linearly with the increase of temperature (0-100 ℃). The spectral line broad and the peak position has a red-shift (12nm). The partial overlap of absorption and emission spectra of quantum dots leads to self-absorption. The increase of self-absorption results in decrease of photoluminescence intensity while the concentration of quantum dots increases.