Organic EL element

摘要

An organic electroluminescent (EL) element comprises: an anode; a cathode; a functional layer disposed between the anode and the cathode, and including a light-emitting layer containing an organic material; a hole injection layer disposed between the anode and the functional layer; and a bank that defines an area in which the light-emitting layer is to be formed, wherein the hole injection layer includes tungsten oxide and includes an occupied energy level that is approximately 1.8 electron volts to approximately 3.6 electron volts lower than a lowest energy level of a valence band of the hole injection layer in terms of a binding energy, the hole injection layer has a recess in an upper surface of the area defined by the bank, and an upper peripheral edge of the recess is covered with a part of the bank.

主权项

1. An organic electroluminescent (EL) element, comprising:
an anode; a cathode; a functional layer disposed between the anode and the cathode, and including a light-emitting layer containing an organic material; a hole injection layer disposed between the anode and the functional layer; and a bank that defines an area in which the light-emitting layer is to be formed, wherein the hole injection layer includes tungsten oxide and includes an occupied energy level that is approximately 1.8 electron volts to approximately 3.6 electron volts lower than a lowest energy level of a valence band of the hole injection layer in terms of a binding energy, the hole injection layer has a recess in an upper surface of the area defined by the bank, and an upper peripheral edge of the recess is covered with a part of the bank, one of an ultraviolet photoelectron spectroscopy and an X-ray photoelectron spectroscopy of the hole injection layer, using a He I line as a light source and a normal line direction of a surface of the substrate as an electron emission angle, exhibits an upward protrusion that is 1.8 electron volts to 3.6 electron volts lower than a lowest energy level of a valence band of the hole injection layer in terms of binding energy, the upward protrusion corresponding to the occupied energy level of the hole injection layer.