OLED (Organic Light-Emitting Diode) is no longer a novelty, it is already widely known since display screens of television, mobile phone started with it earlier, now the general lighting industry comes up with this new technology as well. Comparing to LED, some advantages are mentioned frequently as:
With the OLED sample we get, which is a high CRI version, nominal parameters are:
Testing the items as below:
Most of the tests could be processed directly in the integrating sphere, let’s check out the result (Figure 2).
Figure 2. Color rendition test on high CRI OLED sample.
Not bad, right?
Visual effect quite promising, but we can still sense some problems, as the concluded opinions from us:
Figure 3. Left-LED panel, right-OLED panel.
Although the general color rendering is good, when we compare the spectrum with Yujileds BC series 3000K high CRI LED, the difference is still obvious (Figure 4). The long wave band – which represents the color rendition of red, is narrower and shorter than the current LED phosphor solution we are using, this results in the relatively lower R9 (59), by contrast, currently we already can achieve as high and stable R9 as up to 98. However, R9 is considered as a very important, probably the most important parameter to render skin tone and saturated red.
Figure 4. Spectrum comparison.
So far as we know, OLED is not that competitive comparing to LED, especially when we evaluate it based on high CRI feature, while with different technical solutions and by different product modalities, we can control the high CRI (Ra > 95) LED from 40lm/W to 160lm/W, regarding cost performance, we spend $100 to get this 37lm OLED panel, calculating to lm/$ we feel it is still a kind of luxury product for general lighting applications, at this stage at least.
Testing the central temperature after driving the OLED panel for 10 minutes, we see the thermal dissipation is excellent (Figure 5), but considering the total input power is only ~0.07W in the size of 105mm*55mm, with this power density probably the temperature is not that referential.
Unfortunately we do not have suitable equipment for evaluating the stability and lifespan, the vendor provides a proposal on >10000 hours, but we are not sure if it calculated as L70.
Figure 5. Temperature test after 10 minutes.
After the full test, high CRI OLED interests and impresses us, the overall color rendition and light uniformity are beyond our estimation, while the efficiency and cost are not promising, we expect to see the improvements in the future, at this moment we have questions:
So, what do you think of high CRI OLED?