碲镉汞量子点的离子交换能带调控及其近红外自吸收性质

The band gap regulation of Hg_(x)Cd_(1-x)Te quantum dots by ion exchange and their near-infrared self-absorption characteristics

通过软化学方法制备单分散的CdTe量子点,调节Hg^(2+)的浓度离子交换实现从可见到近红外光谱准连续可调的碲镉汞(Hg_(x)Cd_(1-x)Te)量子点制备。深入分析了近红外Hg_(0.33)Cd_(0.67)Te量子点的变温光致发光及其自吸收特性,研究结果表明:碲镉汞量子点的荧光强度随着温度的升高(0∼100℃)呈线性降低趋势,谱线展宽,峰位发生红移(12 nm);量子点的吸收和发射光谱部分重叠导致自吸收效应随着量子点的浓度增加而增强,导致量子点荧光强度的降低。

In this paper,monodispersed CdTe quantum dots are synthesized by soft chemical method.Meanwhile,mer‐cury cadmium telluride(Hg_(x)Cd_(1-x)Te)quantum dots with the quasi continuous visible to near-infrared spectrum are pre‐pared by ion exchange adjusting the concentration of Hg^(2+).The variable temperature photoluminescence and self-absorp‐tion characteristics of near-infrared Hg_(0.33)Cd_(0.67)Te quantum dots are deeply analyzed.The results indicate that the fluores‐cence intensity of Hg_(x)Cd_(1-x)Te quantum dots decreases linearly with the increase of temperature(0∼100℃).The spectral line broad and the peak position has a red-shift(12 nm).The partial overlap of absorption and emission spectra of quan‐tum dots leads to self-absorption.The increase of self-absorption results in decrease of photoluminescence intensity while the concentration of quantum dots increases.