Organic light emitting diode with transparent electrode and method of making same

A method of making an organic light emitting diode (OLED) device, the method comprising:

• sputter-depositing a first layer comprising indium tin oxide (ITO) on a glass substrate;
• sputter-depositing a second layer comprising ITO on the glass substrate over the first layer comprising ITO to form an electrode structure, so that the first layer comprising ITO is located between at least the substrate and the second layer comprising ITO in the electrode structure, wherein as sputter-deposited the first layer comprising ITO is more oxided than is the second layer comprising ITO;
• heat treating the electrode structure including the glass substrate and the first and second layers comprising ITO thereon at temperature(s) of at least about 500 degrees C. to increase work function of the electrode structure;
• and
• after said heat treating, providing the electrode structure in an OLED device so that an organic light emitting semiconductor layer of the OLED device is located between said electrode structure and another electrode.

A method of making an electrode for use in an organic light emitting diode (OLED) device, the method comprising:

• sputter-depositing a first layer comprising metal oxide on a substrate;
• sputter-depositing a second layer comprising metal oxide on the substrate over and directly contacting the first layer comprising metal oxide to form an electrode structure, wherein the same metal oxide is in both the first and second layers comprising metal oxide, but as sputter-deposited the first layer comprising metal oxide is more oxided than is the second layer comprising metal oxide;
• and
• heat treating the electrode structure including the substrate and the first and second layers comprising metal oxide at temperature(s) of at least about 400 degrees C. in order to increase work function of ITO in the electrode structure and increase visible transmission of the electrode structure.

An organic light emitting diode (OLED) comprising:

• a transparent conductive electrode structure comprising first and second layers comprising the same metal oxide on a substrate, the first layer comprising the metal oxide being located between the substrate and the second layer comprising the metal oxide, and wherein the second layer comprising the metal oxide directly contacts the first layer comprising the metal oxide;
• wherein the same metal oxide is in both the first and second layers comprising the metal oxide, and wherein the first layer comprising the metal oxide is more oxided than is the second layer comprising the metal oxide;
• and
• an organic light emitting layer located between said transparent conductive electrode structure and another electrode, and wherein said transparent conductive electrode structure is on a light emitting side of the organic light emitting layer.