Abstract:
There is disclosed methods of making photosensitive devices, such as flexible photovoltaic (PV) devices, through the use of epitaxial liftoff. Also described herein are methods of preparing flexible PV devices comprising a structure having a growth substrate, wherein the selective etching of protective layers yields a smooth growth substrate that us suitable for reuse.
Abstract:
An organic light emitting device structure having an organic light emitting device (OLED) over a substrate, where the OLED has, for example, an anode, a hole transporting layer (HTL), a first electron transporting layer (ETL) that is doped with a phosphorescent material, a second electron transporting layer (ETL), and a cathode. The OLEDs of the present invention are directed, in particular, to devices that include an emissive layer comprised of an electron transporting host material having a triplet excited state energy level that is higher than the emissive triplet excited state energy level of the phosphorescent dopant material.
Abstract:
A method of depositing organic material is provided. A carrier gas carrying organic material is ejected from a nozzle at a flow velocity that is at least 10% of the thermal velocity of the carrier gas, such that the organic material is deposited onto a substrate. In some embodiments, the dynamic pressure in a region between the nozzle and the substrate surrounding the carrier gas is at least 1 Torr, and more preferably 10 Torr, during the ejection. In some embodiments, a guard flow is provided around the carrier gas.
Abstract:
A first device is provided. The first device includes an organic light emitting device, which further comprises a first electrode, a second electrode, and an organic emissive layer disposed between the first and second electrode. Preferably, the second electrode is more transparent than the first electrode. The organic emissive layer has a first portion shaped to form an indentation in the direction of the first electrode, and a second portion shaped to form a protrusion in the direction of the second electrode. The first device may include a plurality of organic light emitting devices. The indentation may have a shape that is formed from a partial sphere, a partial cylinder, a pyramid, or a pyramid with a mesa, among others. The protrusions may be formed between adjoining indentations or between an indentation and a surface parallel to the substrate.
Abstract:
A first device is provided. The device includes a print head. The print head further includes a first nozzle hermetically sealed to a first source of gas. The first nozzle has an aperture having a smallest dimension of 0.5 to 500 microns in a direction perpendicular to a flow direction of the first nozzle. At a distance from the aperture into the first nozzle that is 5 times the smallest dimension of the aperture of the first nozzle, the smallest dimension perpendicular to the flow direction is at least twice the smallest dimension of the aperture of the first nozzle.
Abstract:
Organic light emitting devices having a low-index electrode and a substrate with a surface treatment are provided. The combination of a relatively low-index electrode and a surface-treated substrate may eliminate guided modes and increase the light outcoupled by the device. It has been found that the combination surprisingly provides up to 1.5 times more outcoupled light than would be expected based on the performance of similar devices having higher-index electrodes.
Abstract:
A method of depositing organic material is provided. A carrier gas carrying an organic material is ejected from a nozzle at a flow velocity that is at least 10% of the thermal velocity of the carrier gas, such that the organic material is deposited onto a substrate. In some embodiments, the dynamic pressure in a region between the nozzle and the substrate surrounding the carrier gas is at least 1 Torr, and more preferably 10 Torr, during the ejection. In some embodiments, a guard flow is provided around the carrier gas. In some embodiments, the background pressure is at least about 10e-3 Torr, more preferably about 0.1 Torr, more preferably about 1 Torr, more preferably about 10 Torr, more preferably about 100 Torr, and most preferably about 760 Torr. A device is also provided. The device includes a nozzle, which further includes a nozzle tube having a first exhaust aperture and a first gas inlet; and a jacket surrounding the nozzle tube, the jacket having a second exhaust aperture and a second gas inlet. The second exhaust aperture completely surrounds the first tube aperture. A carrier gas source and an organic source vessel may be connected to the first gas inlet. A guard flow gas source may be connected to the second gas inlet. The device may include an array of such nozzles.
Abstract:
A method of fabricating an organic film is provided. A non-reactive carrier gas is used to transport an organic vapor. The organic vapor is ejected through a nozzle block onto a cooled substrate, to form a patterned organic film. A device for carrying out the method is also provided. The device includes a source of organic vapors, a source of carrier gas and a vacuum chamber. A heated nozzle block attached to the source of organic vapors and the source of carrier gas has at least one nozzle adapted to eject carrier gas and organic vapors onto a cooled substrate disposed within the vacuum chamber.
Abstract:
Organic light emitting devices are described wherein the emissive layer comprises a host material containing an emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, and the emissive molecule is selected from the group of phosphorescent organometallic complexes, including cyclometallated platinum, iridium and osmium complexes. The organic light emitting devices optionally contain an exciton blocking layer. Furthermore, improved electroluminescent efficiency in organic light emitting devices is obtained with an emitter layer comprising organometallic complexes of transition metals of formula L2MX, wherein L and X are distinct bidentate ligands. Compounds of this formula can be synthesized more facilely than in previous approaches and synthetic options allow insertion of fluorescent molecules into a phosphorescent complex, ligands to fine tune the color of emission, and ligands to trap carriers.