Patent ID: 8026512

Claim:
An electroluminescent (EL) device comprising: a semiconductor structure including: a first higher mobility semiconductor layer having a first mobility; a second higher mobility semiconductor layer having a second mobility; and a lower mobility semiconductor layer formed between the first higher mobility semiconductor layer and the higher mobility second semiconductor layer, the lower mobility semiconductor layer having a third mobility that is less than the first mobility and the second mobility, wherein the ratio of the first mobility to the third mobility and the ratio of the second mobility to the third mobility are each at least 2:1; where the semiconductor structure includes EL semiconducting material in at least one of the first higher mobility semiconductor layer, the second higher mobility semiconductor layer, or the lower mobility semiconductor layer; a first electrode coupled to the first higher mobility semiconductor layer of the semiconductor structure; a second electrode coupled to the second higher mobility semiconductor layer of the semiconductor structure; and the first and second higher mobility semiconductor layers are formed from polarizable bipolar semiconductor material.