【摘要】 弱发光样品量子产率测量困难，提出了四线法的测量方法，采用荧光光谱仪和积分球附件相结合的测量方式，主要利用衰减片的添加来实现样品荧光发射信号的相对增强，较大程度提高了弱发光样品量子产率测量的准确度。采用该装置测定了标准物质YG晶体的绝对量子产率为42.0%,相对误差0.95%,验证了荧光分光光度计和积分球结合的方式用于绝对量子产率测量的可行性。然后介绍了四线法用于绝对量子产率测量的依据、测量过程及数据处理方法。采用四线法测量了标准样品罗丹明6G和硫酸奎宁的绝对量子产率，结果显示相对误差分别为1.3%和1.1%,远小于5.0%(量子产率允许误差),表明该方法具有较高的准确性。详细探讨了实验条件对四线法绝对量子产率测量结果的影响，发现测试的最佳条件为衰减片放于激发端、衰减后的光源强度达到荧光光谱仪检测器光强线性响应区间的上限。采用不同浓度罗丹明6G溶液模拟弱发光、中强发光以及强发光样品，分别用二线法(常规方法)和四线法测量各溶液的绝对量子产率，将测试结果与文献报导数据对比，发现四线法更适用于弱发光和中强发光样品绝对量子产率的测量，尤其用于弱发光样品测量时，相对误差由二线法的10%降至四线法的0.32%。更多还原

【Abstract】 Aiming at the difficulty of the absolute quantum yield measurement of weak luminescence samples, a Four-Line method is proposed, mainly using the neutral density attenuator to realize the relative enhancement of the sample emission signal. The fluorescence spectrometer and integrating sphere measure the absolute quantum yield. To investigate the feasibility of the Four-Line method, the quantum yields of standard samples rhodamine 6G and quinine sulfate were measured. The results show that the relative errors are 1.3% and 1.1%, respectively, far less than 5.0%, indicating this method has high accuracy. The influence of experimental conditions on quantum yield measured by the Four-Line method is discussed. It is found that the best experimental condition is that the neutral density attenuator is placed at the excitation position, and the attenuated light source intensity reaches the upper limit of the linear response interval of the detector. They used rhodamine 6G solution with different concentrations to simulate weak, medium, strong, and strong luminescence samples. The quantum yields of the solutions were measured by the Two-Line method(conventional method) and the Four-Line method, respectively, and the results were compared with those reported in the literature. The research shows that the Four-Line method is more suitable for the absolute quantum yield measurement of weak and medium luminescence samples, and the relative error is reduced from 10% by the Two-Line method to 0.32%.更多还原