Organic EL element and organic EL panel
A semi-transmissive film is provided underneath a transparent electrode of an organic EL element. The optical length of the interval between the upper surface of the semi-transmissive film and the lower surface of a counter electrode serving as a reflective layer is configured such that this interval functions as a microresonator for selecting light having a specific wavelength. Further, a light-shielding film is provided in a position corresponding to the peripheral portion of the semi-transmissive film, so as to prevent light having a different color from being ejected due to non-uniformity in the optical length.
1. An organic EL panel comprising a plurality of organic EL elements each including an organic layer provided between first and second electrodes and emitting light when a voltage is applied between the first and second electrodes to allow a current to flow in the organic layer, wherein
the first electrode includes a semi-transmissive layer which reflects light emitted from the organic layer;
the second electrode includes a reflective layer for reflecting light emitted from the organic layer;
an interval between the reflective layer and the semi-transmissive layer is configured to have a predetermined optical length, such that, when light generated in the organic layer is repetitively reflected between the reflective layer and the semi-transmissive layer, the interval between the reflective layer and the semi-transmissive layer functions as a microresonator which intensifies and selects light having a specific wavelength and ejects the selected light through the semi-transmissive layer;
a light-shielding film which shields light ejected from the microresonator is provided in a position corresponding to a portion of the microresonator having a non-uniform optical length;
the plurality of organic EL elements are formed on a substrate, and a plurality of thin film transistors for controlling supply of current to the plurality of organic EL elements are provided on the substrate;
the thin film transistors and the first electrode are connected via contact holes;
the portion of the microresonator having non-uniform optical length is generated by the existence of the contact hole;
the light shielding is structured to shield light that goes through the portion of the microresonator having non-uniform optical length; and
the light shielding film is superposed on the contact holes.
2. An organic EL panel as defined in claim 1 , wherein
the first electrode is a laminated structure composed of the semi-transmissive layer and a transparent electrode; and
the second electrode is a metal electrode which functions as the reflective layer.
3. An organic EL panel as defined in claim 2 , wherein
among the semi-transmissive layer and the transparent electrode, the transparent electrode is located closer to the organic layer.
4. An organic EL panel as defined in claim 3 , wherein
the first electrode is an anode, while the second electrode is a cathode.
5. An organic EL panel as defined in claim 1 , wherein
the plurality of organic EL elements are arranged in a layer above the thin film transistors, and
the light-shielding film is positioned in a layer between the thin film transistors and the substrate.
6. An organic EL panel as defined in claim 1 , wherein
the plurality of organic EL elements are formed on a pixel substrate;
a counter substrate is arranged opposing the pixel substrate; wherein the light shielding film is formed on the counter substrate.