Abstract: Disclosed are criteria for a lattice matched, multilayer, organic crystal heterostructure. Current organic devices (e.g., photovoltaics, light emitting diodes, or transistors) rely on amorphous material despite superior charge transport properties of crystalline organic semiconductors. Achieving a fully crystalline device architecture requires growth of a molecular crystal atop a different one, or heteroepitaxy, and is particularly relevant in organic semiconductor devices that demand multiple layers of different molecules. This challenge is complicated when attempting to stack highly ordered layers needed for crystalline devices because strategies are needed to ensure that each layer grows crystalline. It is shown herein that lattice matching alone is not sufficient for successful organic heteroepitaxy deposited via physical vapor deposition.

Abstract: Organic-inorganic perovskite nanoparticle compositions are described herein. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with ligands of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

Abstract: Organic-inorganic perovskite nanoparticle compositions are described herein. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with ligands of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

Abstract: Organic-inorganic perovskite nanoparticle compositions are described herein. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with ligands of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

Abstract: The disclosure relates to organic photovoltaic cells comprising a heterojunction structure formed by a first organic donor layer and a first organic acceptor layer, and further comprising a second organic acceptor layer adjacent to the first organic acceptor layer and/or a second organic donor layer adjacent to the first organic donor layer. The materials of the first acceptor layer and the second acceptor layer are selected to allow exciton dissociation by charge transfer at their interface, and to simultaneously allow exciton energy transfer at their interface. The materials of the first donor layer and the second donor layer are selected to allow exciton dissociation by charge transfer at their interface, and to simultaneously allow exciton energy transfer at their interface. Organic photovoltaic cells of the present invention may have a high short-circuit current density, a good open-circuit voltage and a good fill factor.

Abstract: Organic-inorganic perovskite nanoparticle compositions are described herein. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with ligands of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

Abstract: The disclosure relates to organic photovoltaic cells comprising a heterojunction structure formed by a first organic donor layer and a first organic acceptor layer, and further comprising a second organic acceptor layer adjacent to the first organic acceptor layer and/or a second organic donor layer adjacent to the first organic donor layer. The materials of the first acceptor layer and the second acceptor layer are selected to allow exciton dissociation by charge transfer at their interface, and to simultaneously allow exciton energy transfer at their interface. The materials of the first donor layer and the second donor layer are selected to allow exciton dissociation by charge transfer at their interface, and to simultaneously allow exciton energy transfer at their interface. Organic photovoltaic cells of the present invention may have a high short-circuit current density, a good open-circuit voltage and a good fill factor.

Abstract: A method for fabricating an organic photovoltaic cell includes providing a first electrode; depositing a series of at least seven layers onto the first electrode, each layer consisting essentially of a different organic semiconductor material, the organic semiconductor material of at least an intermediate layer of the sequence being a photoconductive material; and depositing a second electrode onto the sequence of at least seven layers. One of the first electrode and the second electrode is an anode and the other is a cathode. The organic semiconductor materials of the series of at least seven layers are arranged to provide a sequence of decreasing lowest unoccupied molecular orbitals (LUMOs) and a sequence of decreasing highest occupied molecular orbitals (HOMOs) across the series from the anode to the cathode.

Abstract: An organic photovoltaic cell includes an anode and a cathode, and a plurality of organic semiconductor layers between the anode and the cathode. At least one of the anode and the cathode is transparent. Each two adjacent layers of the plurality of organic semiconductor layers are in direct contact. The plurality of organic semiconductor layers includes an intermediate layer consisting essentially of a photoconductive material, and two sets of at least three layers. A first set of at least three layers is between the intermediate layer and the anode. Each layer of the first set consists essentially of a different organic semiconductor material having a higher LUMO and a higher HOMO, relative to the material of an adjacent layer of the plurality of organic semiconductor layers closer to the cathode. A second set of at least three layers is between the intermediate layer and the cathode.

Abstract: The disclosed technology relates to a light-emitting diode (LED) and a method of fabricating the same. In one aspect, the LED includes a GaN p-n junction formed at a junction between a p-type GaN layer and an n-type GaN layer. The LED further includes a first metal electrode layer provided on the p-type GaN layer, where the first metal electrode layer is configured to reflect light emitted by the p-n junction towards a light emitting side of the LED. The LED additionally includes an attachment layer interposed between and configured to electrically connect the p-type GaN layer and the metal electrode layer, wherein the attachment layer comprises a transition metal oxide and is configured to transmit light emitted by the p-n junction and to transmit light reflected by the metal electrode layer.

Abstract: The disclosed technology relates to a light-emitting diode (LED) and a method of fabricating the same. In one aspect, the LED includes a GaN p-n junction formed at a junction between a p-type GaN layer and an n-type GaN layer. The LED further includes a first metal electrode layer provided on the p-type GaN layer, where the first metal electrode layer is configured to reflect light emitted by the p-n junction towards a light emitting side of the LED. The LED additionally includes an attachment layer interposed between and configured to electrically connect the p-type GaN layer and the metal electrode layer, wherein the attachment layer comprises a transition metal oxide and is configured to transmit light emitted by the p-n junction and to transmit light reflected by the metal electrode layer.

Abstract: A method for fabricating an organic photovoltaic cell includes providing a first electrode; depositing a series of at least seven layers onto the first electrode, each layer consisting essentially of a different organic semiconductor material, the organic semiconductor material of at least an intermediate layer of the sequence being a photoconductive material; and depositing a second electrode onto the sequence of at least seven layers. One of the first electrode and the second electrode is an anode and the other is a cathode. The organic semiconductor materials of the series of at least seven layers are arranged to provide a sequence of decreasing lowest unoccupied molecular orbitals (LUMOs) and a sequence of decreasing highest occupied molecular orbitals (HOMOs) across the series from the anode to the cathode.

Abstract: An organic optoelectronic device and a method for manufacturing the same are disclosed. In one aspect, the device has a stack of layers. The stack includes a buffer layer and a first organic semiconductor layer adjacent to the buffer layer at a first side of the buffer layer. The buffer layer includes at least one transition metal oxide doped with a metal.

Abstract: An organic photovoltaic cell includes an anode and a cathode, and a plurality of organic semiconductor layers between the anode and the cathode. At least one of the anode and the cathode is transparent. Each two adjacent layers of the plurality of organic semiconductor layers are in direct contact. The plurality of organic semiconductor layers includes an intermediate layer consisting essentially of a photoconductive material, and two sets of at least three layers. A first set of at least three layers is between the intermediate layer and the anode. Each layer of the first set consists essentially of a different organic semiconductor material having a higher LUMO and a higher HOMO, relative to the material of an adjacent layer of the plurality of organic semiconductor layers closer to the cathode. A second set of at least three layers is between the intermediate layer and the cathode.

Abstract: An organic photosensitive optoelectronic device includes an anode, a cathode, and a donor-acceptor heterojunction between the anode and the cathode, the heterojunction including a donor-like material and an acceptor-like material, wherein at least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound, wherein the subporphyrin or subporphyrazine compound includes boron.

Abstract: An organic photosensitive optoelectronic device includes an anode, a cathode, and a donor-acceptor heterojunction between the anode and the cathode, the heterojunction including a donor-like material and an acceptor-like material, wherein at least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound, wherein the subporphyrin or subporphyrazine compound includes boron.

Abstract: An organic photosensitive optoelectronic device, having a donor-acceptor heterojunction of a donor-like material and an acceptor-like material and methods of making such devices is provided. At least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound; and/or the device optionally has at least one of a blocking layer or a charge transport layer, where the blocking layer and/or the charge transport layer includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound.

Abstract: An organic photosensitive optoelectronic device, having an anode, a cathode, and an organic blocking layer between the anode and the cathode is described, wherein the blocking layer comprises a phenanthroline derivative, and at least partially blocks at least one of excitons, electrons, and holes.

Abstract: An organic optoelectronic device and a method for manufacturing the same are disclosed. In one aspect, the device has a stack of layers. The stack includes a buffer layer and a first organic semiconductor layer adjacent to the buffer layer at a first side of the buffer layer. The buffer layer includes at least one transition metal oxide doped with a metal.

Abstract: An organic photosensitive optoelectronic device, having a donor-acceptor heterojunction of a donor-like material and an acceptor-like material and methods of making such devices is provided. At least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound; and/or the device optionally has at least one of a blocking layer or a charge transport layer, where the blocking layer and/or the charge transport layer includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound.