850 research outputs found

    Self-powered GHZ solution-processed hybrid perovskite photodetectors

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    Organic-inorganic hybrid perovskite (OIHP) based photo-responsive devices include an OIHP active layer disposed between a cathode layer and an anode layer, and an electron extraction layer disposed between the cathode layer and the active layer. The electron extraction layer includes a layer of C60 directly disposed on the active layer. The active layer includes an organometal trihalide perovskite layer (e.g., CH3NH3PbI2X, where X includes at least one of Cl, Br, or I)

    METHOD FOR SINGLE CRYSTAL GROWTH OF PHOTOVOLTAIC PEROVSKITE MATERIAL AND DEVICES

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    Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container , also including at least one small perovskite single crystal , and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows , in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate . For example , a top portion of the substrate external to the solution may be cooled

    Analysis of Hu\u27s Moment Invariants on Image Scaling and Rotation

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    Moment invariants have been widely applied to image pattern recognition in a variety of applications due to its invariant features on image translation, scaling and rotation. The moments are strictly invariant for the continuous function. However, in practical applications images are discrete. Consequently, the moment invariants may change over image geometric transformation. To address this research problem, an analysis with respect to the variation of moment invariants on image geometric transformation is presented, so as to analyze the effect of image\u27s scaling and rotation. Finally, the guidance is also provided for minimizing the fluctuation of moment invariants

    PASSIVATION OF DEFECTS IN PEROVSKITE MATERIALS FOR IMPROVED SOLAR CELL EFFICIENCY AND STABILITY

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    Semiconductor devices , and methods of forming the same , include a cathode layer , an anode layer , and an active layer disposed between the cathode layer and the anode layer , wherein the active layer includes a perovskite layer . A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer , the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer

    Passivation of defects in perovskite materials for improved solar cell efficiency and stability

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    Semiconductor devices, and methods of forming the same, include a cathode layer, an anode layer, and an active layer disposed between the cathode layer and the anode layer, wherein the active layer includes a perovskite layer. A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer, the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer

    Compositionally Graded Bulk Heterojunction Devices and Methods of Manufacturing The Same

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    Systems and methods are described to form compositionally graded BHJ structures utilizing solvent-fluxing techniques. In implementations, the systems and methods described herein involve a high boiling point additive, a solution of a polymer donor and an acceptor, a substrate material, a working solvent, and a flux solvent for formation of compositionally graded BHJ structures

    A new seal verification for Chinese color seal

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    Automatic seal imprint identification system is highly demanded in oriental countries. Even though several seal identification techniques have been proposed, it is seldom to find the papers on the recovery of lost seal imprint strokes caused by superimposition. In this paper, a new seal verification for Chinese color seal is proposed. This approach segments the seal imprint from the input image in terms of the adaptive thresholds. The lost seal imprint strokes are recovered based on the text stroke width that can be detected automatically. In addition, the moment-based seal verification is to compare the reference seal imprint and the recovered one. Experimental results show that the proposed method is able to correctly and efficiently verify the genuine and forgery seal imprint
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