Organic electroluminescent devices with improved stability and efficiency

摘要

An organic luminescent layer for use in an electroluminescent device with improved operating life includes an organic host material capable of sustaining both hole and electron injection and recombination. The layer also includes at least two dopants: a first dopant capable of accepting energy of electron-hole combinations in the host material; and a second dopant capable of trapping the holes from the host material. The first dopant being selected so that the band gap energy of the first dopant is less than the bandgap energy of the host material and the second dopant being selected to have a hole trapping energy level above the valance band of the host material.