荧光量子效率绝对法测量系统校准及不确定度评定

荧光量子效率是发射与吸收的光子数之比,是表征荧光材料发光性能的关键参数。然而,用于绝对法测量荧光量子效率的光路和探测器未经校准溯源或是校准方法不当,会造成测量光谱的不准确,进一步影响荧光量子效率计算结果的不准确。采用汞氩灯对单色仪进行校准,保证了激发波长和发射波长的准确性,利用标准辐射源对光路、发射单元单色仪和探测器进行光谱相对强度校准,保证了激发波段和发射波段光谱相对强度的准确性;最后从测量模型出发,对测量不确定度进行了分析,得到在300~360nm的激发光波段和370~900nm的发射光波段内相对合成标准不确定度为3.58%,相对扩展不确定度为7.16%,k=2。通过对单色仪波长校准以及对光谱相对强度进行校准,为荧光量子效率的准确测量提供了参考。

Calibration and Uncertainty Evaluation of Fluorescence Quantum Efficiency Absolute Measurement System

The quantum efficiency of fluorescence is the ratio of photons emitted and absorbed, and is the key parameter to characterize the properties of fluorescent materials. However, if the optical path and detector used for absolute measurement of fluorescence quantum efficiency are not calibrated and traced back or the calibration method is not correct, it will cause the inaccurate measurement spectrum and further cause the inaccurate calculation results of fluorescence quantum efficiency. The mercury argon lamp is used to calibrate the monochromator to ensure the accuracy of excitation wavelength and emission wavelength. The standard radiation source is used to calibrate the spectral relative intensity of the light path, the monochromators of the emission unit and the detector, which ensures the accuracy of the spectral relative intensity of the excitation band and the emission band. Finally, the uncertainty of measurement is analyzed based on the measurement model, the results show that the relative standard uncertainty is 3.58%, the relative expanded uncertainty is 7.16%,k=2 in the excitation band of 300~360nm and the emission band of 370~900nm. By calibrating the monochromators and the spectral relative intensity, it can provide a reference for the accurate measurement of fluorescence quantum efficiency.