| abstract |
The present invention describes a light emitting device comprising at least one substrate (1), an anode (2), a first hole transport layer (3), a light emitting layer (5) and a cathode (6), and the first hole blocking layer (4). It is located between the first hole transport layer 3 and the light emitting layer 5. The hole blocking layer 4 reduces the density of holes reaching the light emitting layer 5, so that the density of holes, which are generally majority charge carriers, can be matched to the current. |