Oledworks Gmbh

Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Jeffrey Spindler

John W Hamer

Marina Kondakova

Uwe Vogel

Bernd Richter

Philipp Wartenberg

Gerd Bunk

A microdisplay comprising a light emitting OLED stack on top of a silicon-based backplane with individually addressable pixels and control circuitry wherein the light emitting OLED stack has three or more OLED units between a top electrode and a bottom electrode; and the control circuitry of the silicon-based backplane comprises at least two transistors with their channels connected in series between an external power source VDD, and the bottom electrode of the OLED stack. The light-emitting OLED stack preferably has a Vth of at least 7.5V or more. The control circuit can include a protection circuit comprised of a p-n diode, preferably a bipolar junction transistor.

Stacked OLED microdisplay with low-voltage silicon backplane

A display comprising a light emitting OLED stack on top of a silicon-based backplane with individually addressable pixels and control circuitry wherein the control circuitry of the silicon-based backplane comprises at least one driving transistor where a first terminal of the driving transistor is electrically connected to an external power source VDD, and the second terminal of the driving transistor is electrically connected to the bottom electrode of the OLED stack; wherein the gate of the driving transistor is controlled by a data signal which supplied by a scan transistor controlled by a signal from select line SELECT; and the control circuitry additionally comprises a protection circuit comprising a bipolar junction transistor. There can be a switch transistor between the scan transistor and the gate of the driving transistor for microdisplay applications. The OLED stack can comprise two or more OLED light-emitting units.

OLED display with protection circuit

An OLED lighting device comprising: a blue light-emitting unit with a blue-light fluorescent, phosphorescent or TADF emitter; a yellow light-emitting electroluminescent unit comprising a green phosphorescent emitter, a red phosphorescent emitter and at least one non-emitting host; wherein the blue light-emitting unit and the yellow light-emitting unit are separated by a mixed interlayer with two non-emitting charge-carrier materials. Desirably, the yellow-light emitting unit essentially consists of a green phosphorescent emitter, a red phosphorescent emitter and a single non-emitting host. The mixed interlayer desirably has more than 50% of a hole-transporting material and an electron-transporting material. The Triplet Energy of both materials in the mixed interlayer can be higher than the Triplet Energies of the R and G phosphorescent dopants. The HOMOs of both materials in the mixed interlayer are more negative than the HOMO of the host in the yellow unit but less negative than the HOMO of the host in the blue unit. The LUMOs of the materials in the mixed interlayer can be more negative than the LUMO of the host in the yellow unit but less negative than the LUMO of the host in the blue unit. The OLED lighting device is spectrally tunable according to the supplied power.

Spectrally tunable stacked OLED

A method for making an OLED lighting panel is disclosed. A patterned inorganic insulating layer is used to enclose an area over a first electrode layer leaving portions of the first electrode layer and substrate adjacent to the outside of the enclosure exposed. After uniform deposition of the organic layer(s), the organic layer(s) are selectively removed over the inorganic insulating layer and an adjacent portion of the substrate to form a sealing region. After uniform deposition of the second electrode, the enclosed area is encapsulated and any overlying layers over the first and second electrodes outside the enclosed area are removed resulting in an OLED within the enclosed area with electrode contact pads outside the enclosed area. The OLED can be manufactured at low cost with no or limited use of shadow masking and is suitable for roll-to-roll processes.

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Ontario, NY, United States of America

Jeffrey Spindler