CRAIC Technologies is the worlds leading developer of UV-visible-NIR range scientific instruments for microanalysis. These include the QDI series UV-visible-NIR microspectrophotometer instruments designed to help you non-destructively measure the optical properties of microscopic samples. CRAIC's UVM series microscopes cover the UV, visible and NIR range and help you analyze with sub-micron resolutions far beyond the visible range. CRAIC Technologies also has the CTR series Raman microspectrometer for non-destructive analysis of microscopic samples. And don't forget that CRAIC proudly backs our microspectrometer and microscope products with unmatched service and support.
Development of Organic Light Emitting Diodes (OLEDs)
Organic Light Emitting Diodes (OLEDs) would lead the next generation of flat panel displays. OLEDs have many advantages over traditional LCD displays as they do not require backlight and are, therefore, less massive and use less energy. Pixels are divided into Red, Green and Blue and they generate their own light. As a result they have increased brightness and allow wider viewing angle up to 160°. They also have faster response time and can be refreshed at a rate 3 times of what is required for standard video. However, the pixels are microscopic in size and so, it is difficult to quantify their intensity and color relative to one another using current visual and imaging techniques. It is also difficult to locate individual defective pixels of this size.
Emission Microspectroscopy Analysis of OLED Pixels
The QDI 302 FPD™ microscope spectrophotometer from CRAIC Technologies provides a perfect solution with a quick, easy and non-destructive way of studying the emission microspectroscopy of each OLED pixel. The QDI 302 FPD™ can be attached to a probe station, a standard microscope or integrated with in-line instrumentation. Using programmable staging and CRAIC MINERVA™ software, each pixel in the flat panel display can be measured for both intensity and color accuracy.
Studying the Absorption Spectroscop of OLED Display Using A Spectrophotometer
Figure 1 & 2 show how the spectrophotometer was used to sample an OLED display with aperture-size smaller than the pixel in order to study the absorption spectroscopy. The spectrum in a wide range of 350 to 900 nm is plotted in Figure 3, which brings out distinct characteristics of each pixel. A comparison of such measurements with that of a good ‘standard’ quality pixel would reveal whether any degradation of color or quality has happened to the test sample.
Figure 1. Blue (color masked) pixel sampled with an aperture size of 24 X 24 micron2
Figure 2. Yellow (color-masked) pixel sampled with an aperture size of 6 X 6 micron2
Figure 3. Spectrum of blue and yellow (color-masked) OLED pixels
The QDI 302 FPD™ can also be configured for reflectance and transmittance so that even un-powered displays can be analyzed for their colorimetric accuracy. The colorimetric coordinates for each individual pixel can also be generated. The thickness of thin films deposited on OLED substrates can also be monitored with the addition of CRAIC’s QDI FilmPro™ software. Additionally, groups of pixels can be analyzed to determine the presence of mura in display units and the process can be automated.
This information has been sourced, reviewed and adapted from materials provided by CRAIC Technologies.
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