UniversalPHOLED technology and materials have become recognized for their key role in making OLEDs well suited for battery-operated mobile devices, such as smart phones, as well as for large-area TVs and white lighting. To demonstrate this advantage, we have modeled the power consumption of an active-matrix OLED (AMOLED) using our UniversalPHOLED technology and material, as compared to an AMLCD. Based on a 4” diagonal display, operating at 300 cd/m2 with video rate (40% pixels on), the power savings are significant.
Low temperature rise
Because electrical energy that is not converted into light is converted into heat, displays and lights generally experience a temperature rise while operating. This elevated temperature becomes especially palpable in a large-sized OLED TV or lamp. PHOLED technology can dramatically reduce this increase. For example, the temperature rise in the FL-OLED TV would be about 30°C while the temperature rise would be reduced to 10 - 17°C with PHOLED technology (assuming a 40” diagonal AMOLED). A low operating temperature is very important. It prolongs OLED lifetime as degradation increases with increasing temperature. It also reduces the amount of air conditioning required to remove the generated heat - making PHOLED technology an important element in any “green” or environmental building strategy.
Today, amorphous silicon (a-Si) backplane technology is the incumbent for AMLCDs, with a mature, low-cost installed manufacturing base. Low temperature polycrystalline silicon (LTPS), a relative newcomer, uses more complex and therefore higher cost processes. However, LTPS is higher performance - offering higher carrier mobility so that driving circuitry can be integrated directly onto the substrate for lower cost, esp. for small-area displays. In addition, as LTPS transistors can be smaller than their a-Si counterparts, they can ease the fabrication of very high resolution displays. Conventional wisdom has also suggested that the higher mobility of LTPS would be required to meet OLED's high current drive conditions. This was the case until PHOLED technology was developed. The lower current drive of a PHOLED reduces the current requirements of the TFT backplane, thus reducing its mobility requirements. As a result, PHOLED technology has become a key enabler for the possible use of a-Si backplanes in large-area displays. In the future, PHOLEDs may also help enable the adoption of lower-cost organic TFTs. Also, there is an increasing interest in pursuing metal oxide TFTs for display backplanes. Once again, the lower current requirements of our PHOLEDs lowers the power consumed in the backplane. As a result, our PHOLED technology should also work very well with metal oxide TFT technology as it matures into production.