UV胶基底中IV-VI族PbSe纳晶量子点近红外光谱的吸收截面和辐射截面

Near IR Absorption-Emission Cross-Sections of IV-VI Group PbSe Quantum Dots Doped in UV Gel

测量了三种不同直径(4.5,5.0,5.6nm)的IV-VI族PbSe量子点的近红外吸收光谱,给出了吸收峰值波长随量子点直径变化的经验公式。用吸收光谱法,根据Lambert-Beer定律,测量了光谱的吸收截面峰值和吸收系数及其随波长和掺杂浓度的变化,发现吸收截面对掺杂浓度有弱相关性,得到了吸收截面随掺杂浓度变化的指数近似表达式。测量了量子点的荧光辐射谱,由McCumber关系和实测的吸收截面,确定了量子点光谱的辐射截面峰值及随波长的变化。这些光谱截面数据对PbSe量子点掺杂的增益型器件和传感器设计有重要的意义。

A linear empirical formula of the absorption-peak wavelength depending on quantum dots （QDs） diameters is presented by measuring the near IR-absorption spectra of PbSe QDs with three diameters （4.5, 5.0, 5.6 nm）. Both the absorption cross-section and absorption coefficient of QDs varying with the doping concentration and wavelength are determined by absorption-spectrum method and according to Lambert-Beer＇s law. There is evidence to show that the absorption is weak dependent on the doping concentration, which can be expressed by an exponential decrease with the increased doping concentration. The photoluminescence （PL） spectrum of QDs is measured, and the PL-cross-section peak varying with wavelength is determined according to McCumber＇s relationship between the absorption and emission. As the primary spectrum data of the QDs, the suggested cross-sections are useful for designing photoelectronic gain devices and sensors doped with QDs.