1. Field of the Invention
The present invention relates to an organic electroluminescent device and organic electroluminescent display device having enhanced efficiency.
2. Discussion of the Related Art
With the advent of the information era, the field of displays, which visually display electrical information signals, has rapidly developed. In line with such trend, a variety of ultra-thin and light flat display devices with low power consumption have been developed.
Examples of such flat display devices include, but are not limited to, a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device, and an organic light emitting device (OLED).
In particular, OLEDs are self-emissive and have faster response time, higher luminous efficacy, higher brightness and wider viewing angle than other flat display devices. An OLED includes an anode, a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, an electron injection layer, and a cathode.
Such OLEDs include, between first and second electrodes, a single light emitting unit including a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, and an electron injection layer. However, recently, multiple light emitting units are formed between first and second electrodes.
However, blue light emitting units included in conventional multiple light emitting units include fluorescent blue emission layers. In this regard, a blue emission layer has a lower efficiency than emission layers that realize other colors and thus total panel efficiency is also reduced.