High Efficient Green Emission from Organic Multi-quantum Wells Structure

Organic green light emitting devices (LEDs) with multi-quantum wells (MQWs) structure were fabricated. Aromatic diamine was used as hole-transporting layer and potential barrier layer; tris (8-hydroxyquinoline) aluminum acted as electron transporting layer and MQWs green emitting layer. The influence of the barrier layer thickness and quantum well number to the device performance was also investigated. The barrier thickness must be thin (such as 4nm) enough to tunnel through and distribute charge carriers uniformly in different wells (mainly electrons). The organic MQWs LEDs showed enhanced electroluminescent efficiencies. Maximum luminous efficiency and external quantum efficiency were 1.241m/W and 1.04%, respectively.