Abstract:
Embodiments of the invention can provide organic light-emitting devices (OLEDs) with enhanced outcoupling efficiency. Specific embodiments can enhance the outcoupling efficiency by more than four times. Embodiments of the invention incorporate microlens 5 arrays on the emitting surface of a top-emission OLED. Incorporation of microlens arrays on the emitting surface of a top-emission OLED can greatly enhance the outcoupling efficiency in OLEDs. With a microlens array attached to the emitting surface, much of, if not all, of the waveguiding modes can be extracted. The microlens array can be fabricated using the inkjet printing method or using other methods, including molding.
Abstract:
The preparation of microlenses on a substrate and light emitting devices employing microlenses on the surface from which light is emitted is described. The miscrolenses are formed on a surface that has been coated to have functionality that promotes a sufficiently large contact angle of the microlense on the surface and contains functionality for bonding the microlense to the coating. The microlenses are formed on the coating by deposition of a microlense precursor resin as a microdrop by inkjet printing and copolymerizing the resin with the bonding functionality in the coating. The coating can be formed from a mixture of silane coupling agents that contain functionality in some of the coupling agents that is copolymeriable with the resin such that the microlens can be formed and bonded to the surface by photopolymerization.
Abstract:
Embodiments of the invention pertain to the use of alloyed semiconductor nanocrystals for use in solar cells. The use of alloyed semiconductor nanocrystals offers materials that have a flexible stoichiometry. The alloyed semiconductor may be a ternary semiconductor alloy, such as AxB1-xC or AB1-yCy, or a quaternary semiconductor alloy, such as AxByC1-x-yD, AxB1-xCyD1-y or ABxCyD1-x-y (where A, B, C, and D are different elements). In general, alloys with more than four elements can be used as well, although it can be much harder to control the synthesis and quality of such materials. Embodiments of the invention pertain to solar cells having a layer incorporating two or more organic materials such that percolated paths for one or both molecular species are created. Specific embodiments of the invention pertain to a method for fabricating nanostructured bulk heterojunction that facilitates both efficient exciton diffusion and charge transport. Embodiments of the subject invention pertain to a solar cell having an architecture that allows for efficient harvesting of solar energy. The organic solar cell architecture can incorporate a host/guest (or matrix/dopant) material system that utilizes the long diffusion lengths for triplet excitons without compromising light absorption efficiency.
Abstract:
A device is provided having a first electrode, a second electrode, a first photoactive region having a characteristic absorption wavelength λ1 and a second photoactive region having a characteristic absorption wavelength λ2. The photoactive regions are disposed between the first and second electrodes, and further positioned on the same side of a reflective layer, such that the first photoactive region is closer to the reflective layer than the second photoactive region. The materials comprising the photoactive regions may be selected such that λ1 is at least about 10% different from λ2. The device may further comprise an exciton blocking layer disposed adjacent to and in direct contact with the organic acceptor material of each photoactive region, wherein the LUMO of each exciton blocking layer other than that closest to the cathode is not more than about 0.3 eV greater than the LUMO of the acceptor material.
Abstract:
A method which lower the series resistance of photosensitive devices includes providing a transparent film of a first electrically conductive material arranged on a transparent substrate; depositing and patterning a mask over the first electrically conductive material, such that openings in the mask have sloping sides which narrow approaching the substrate; depositing a second electrically conductive material directly onto the first electrically conductive material exposed in the openings of the mask, at least partially filling the openings; stripping the mask, leaving behind reentrant structures of the second electrically conductive material which were formed by the deposits in the openings of the mask; after stripping the mask, depositing a first organic material onto the first electrically conductive material in between the reentrant structures; and directionally depositing a third electrically conductive material over the first organic material deposited in between the reentrant structures, edges of the reentrant structures aligning deposition so that the third electrically conductive material does not directly contact the first electrically conductive material, and does not directly contact the second electrically conductive material.
Abstract:
A device is provided having a first electrode, a second electrode, a first photoactive region having a characteristic absorption wavelength λ1 and a second photoactive region having a characteristic absorption wavelength λ2. The photoactive regions are disposed between the first and second electrodes, and further positioned on the same side of a reflective layer, such that the first photoactive region is closer to the reflective layer than the second photoactive region. The materials comprising the photoactive regions may be selected such that λ1 is at least about 10% different from λ2. The device may further comprise an exciton blocking layer disposed adjacent to and in direct contact with the organic acceptor material of each photoactive region, wherein the LUMO of each exciton blocking layer other than that closest to the cathode is not more than about 0.3 eV greater than the LUMO of the acceptor material.
Abstract:
A device is provided having a first electrode, a second electrode, a first photoactive region having a characteristic absorption wavelength λ1 and a second photoactive region having a characteristic absorption wavelength λ2. The photoactive regions are disposed between the first and second electrodes, and further positioned on the same side of a reflective layer, such that the first photoactive region is closer to the reflective layer than the second photoactive region. The materials comprising the photoactive regions may be selected such that λ1 is at least about 10% different from λ2. The device may further comprise an exciton blocking layer disposed adjacent to and in direct contact with the organic acceptor material of each photoactive region, wherein the LUMO of each exciton blocking layer other than that closest to the cathode is not more than about 0.3 eV greater than the LUMO of the acceptor material.
Abstract:
Embodiments of the invention are directed to quantum dot light emitting diodes (QD-LEDs) where the electron injection and transport layer comprises inorganic nanoparticles (I-NPs). The use of I-NPs results in an improved QD-LED over those having a conventional organic based electron injection and transport layer and does not require chemical reaction to form the inorganic layer. In one embodiment of the invention the hole injection and transport layer can be metal oxide nanoparticles (MO-NPs) which allows the entire device to have the stability of an all inorganic system and permit formation of the QD-LED by a series of relatively inexpensive steps involving deposition of suspensions of nanoparticles and removing the suspending vehicle.
Abstract:
A SolarTurf unit has a plurality of solar blades, each blade comprising a donor-acceptor conjugated polymer (DA-CP) disposed between and electrically contacting a working electrode and a counter electrode where at least one of electrodes is transparent and where the plurality of solar blades have like or different DA-CPs having like color or different colors, for example, green. The SolarTurf unit includes an interconnect strip having a first electrically conductive surface and a second electrically conductive surface separated by an insulator. The working electrodes are electrically connected to the first electrically conductive surface and the counter electrodes are electrically connected to the second electrically conductive surface. The SolarTurf units can be combined into a device for harvesting light energy to provide an electric output. The SolarTurf device can have the appearance of a lawn or other plant, fungi, rock, sand or animal.
Abstract:
Embodiments of the invention can provide organic light-emitting devices (OLEDs) with enhanced outcoupling efficiency. Specific embodiments can enhance the outcoupling efficiency by more than four times. Embodiments of the invention incorporate microlens 5 arrays on the emitting surface of a top-emission OLED. Incorporation of microlens arrays on the emitting surface of a top-emission OLED can greatly enhance the outcoupling efficiency in OLEDs. With a microlens array attached to the emitting surface, much of, if not all, of the waveguiding modes can be extracted. The microlens array can be fabricated using the inkjet printing method or using other methods, including molding.