随着LED技术的不断进步, 已发展出多种波长的大功率LED, 不用昂贵的单色仪, 而采用各种波长的LED作为单色光来制造量子效率仪; 也不需要旋转滤色片轮切换滤色片来避免光栅单色仪中高级次光谱的影响。 LED作为单色光, 可实现无机械运动、 测量速度快、 故障率低的优点。 多只LED焊接在PCB上形成离散型光源, 无法采用常规的椭球面反射镜、 透镜或凹面反射镜进行汇聚。 采用高反射率反射镜片制备成锥形光导管, 将离散型光源发出的光汇聚为一个小光斑, 可以很好地解决离散型光源汇聚难的问题, 同时实现了高的光利用率。 通过测量LED的波峰值、 半峰宽和稳定性, 并与传统的卤素灯和氙灯为光源的传统量子效率仪进行比较, 发现单色光的波峰值与量子效率的测量准确性是正相关的, 波峰值越高, 测量的准确性越高; 半峰宽在5.1~9.5 nm范围内, 半峰宽对测量的准确性没有影响。 采用LED、 卤素灯和氙灯量子效率仪分别测试同一块太阳电池的量子效率, 计算相同波段的积分电流, 与世界先进的氙灯量子效率仪相比, 相对偏差为0.34%, 与卤素灯量子效率仪的相当, 说明半峰宽在5.1~55.7 nm范围内, 测量准确性与半峰宽无明显的相关性; LED的不稳定度为0.4%, 介于氙灯和卤素灯之间。 从这几个方面来看, LED是可以作为单色光用于量子效率的测试。

A mathematical model for the spectra of monocolor light-emitting diodes (LEDs) and phosphor-coated white LEDs at different drive currents is established. The simulation program of the color rendering of a white light LED cluster is developed based on this model. The program can predict not only the spectral power distribution and color rendering index (CRI), but also the number of LEDs, drive currents, input power, and luminous efficacy of a white light LED cluster at a given color temperature according to the requirement of the luminous flux. The experimental results show that the relative spectral power distributions (SPDs) and chromaticity coordinates of the model LED are very close to that of the real LED at different drive currents. Moreover, the correlated color temperature (CCT), CRI, special color rendering index (R9) luminous flux, input power, and luminous efficacy of the white light LED cluster predicted by simulation are also very close to the measured values. Furthermore, a white/red cluster with high rendering (CCT = 2903 K, CRI = 91.3, R9 = 85) and a color temperature tunable warm-white/red/green/blule LED cluster with high rendering (CCT = 2700?6500 K, CRI > 90, R9 > 96) are created.