The ultra thin layers encapsulate the diodes to protect the underneath OLED from moisture and oxygen. The transparent OLED’s white luminance simultaneously reaches emissions of 1000Cd/m² at 4 and 4.6 volts from the bottom and top, respectively. The white OLED efficacy is 11Lm/W and 3Lm/W respectively at 1000Cd/m² for bottom and top emission, which leads to an overall efficiency of 14Lm/W.
Although the OLED structure is optimized when the color coordinates are identical for both sides, the luminance efficiency for each side is slightly reduced to 5Lm/W. This leads to an overall efficiency of 10Lm/W for a 65% transparent white OLED.
CEA-LETI are planning to enahnce the luminance efficiency and the permeation properties of the thin encapsulation layers.
