Disclosed are organic electroluminescent devices employing materials of a
low reduction potential in a layer functioning hole-injection. The
organic electroluminescent devices may employ an anode material having a
relatively low work function. Aluminum may be used in anode. During the
operation, the organic electroluminescent devices may form a virtual
electrode in their internal area, which enhances injection of carriers
from a nearby electrode. Use of aluminum in the anode helps construction
of cathode-emission organic electroluminescent devices.