phosphorescent organic light emitting diode (PHOLED)
Phosphorescent Organic Light Emitting Diode (PHOLED) are phosphorescent OLEDs which, like all other OLEDs, are based on light emission from organic semiconductors. PHOLEDs have a higher light output than fluorescent OLEDs because they are based on phosphorescence. This technology was developed by Universal Display Corporation.
PHOLEDs, like OLEDs, are constructed in multiple layers on a substrate. These include as electrodes the cathode and the anode. When a voltage is applied to these electrodes, the charge carriers, electrons and holes, diffuse from the electrodes into the light-emitting polymer layer, the PHOLED layer, where they recombine and form an exciton. This is a bonded electron-hole pair in a semiconductor. This causes the emission of photons.
PHOLED technology dates back to 2003, PHOLED displays are characterized by a much higher light output compared to OLED displays and TFT displays, and by lower energy consumption. They have brilliant colors and are also environmentally friendly. The CIE color space of pholed colors essentially corresponds to that of the ITU-R recommendationBT.709. As far as light emission is concerned, this is much higher than that of fluorescent OLEDs because the phosphorescent materials used are more energy-efficient. This ultimately benefits battery life and lower temperature rise in the pholed. However, it should be noted that the lifetime of certain color pixels is shorter than that of OLEDs. This is particularly striking in the case of blue color pixels, whose luminosity already decreases significantly after about 20,000 hours and only provides 50% of the original luminosity.
Pholeds can be used in mobile devices, televisions and in lighting technology.