Publications by authors named "Eszter Voroshazi"

Fullerene-based molecules are the archetypical electron-accepting materials for organic photovoltaic devices. A detailed knowledge of the degradation mechanisms that occur in C60 layers will aid in the development of more stable organic solar cells. Here, the impact of storage in air on the optical and electrical properties of C60 is studied in thin films and in devices.

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We report on the degradation of organic photovoltaic (OPV) cells in both indoor and outdoor environments. Eight different research groups contributed state of the art OPV cells to be studied at Pomona College. Power conversion efficiency and fill factor were determined from IV curves collected at regular intervals over six to eight months.

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We present a hole injection layer processed from solution at room temperature for inverted organic solar cells. Bis(2,4-pentanedionato) molybdenum(VI) dioxide (MoO2(acac)2) is used as the precursor for MoOx. Small amounts of Nafion in the precursor solution allow it to form continuous films with good wetting onto the active layers.

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Metal oxide transport layers have played a crucial role in recent progress in organic photovoltaic (OPV) device stability. Here, we measure the stability of inverted and encapsulated polythiophene:fullerene cells with MoO3/Ag/Al composite anode in operational conditions combining solar radiation and 65 °C. Performance loss of over 50% in the first 100 h of the aging is dominated by a drop in the short-circuit current (Jsc).

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The present work is the fourth (and final) contribution to an inter-laboratory collaboration that was planned at the 3rd International Summit on Organic Photovoltaic Stability (ISOS-3). The collaboration involved six laboratories capable of producing seven distinct sets of OPV devices that were degraded under well-defined conditions in accordance with the ISOS-3 protocols. The degradation experiments lasted up to 1830 hours and involved more than 300 cells on more than 100 devices.

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This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPV) devices prepared by leading research laboratories. All devices have been shipped to and degraded at RISØ-DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work, we apply the Incident Photon-to-Electron Conversion Efficiency (IPCE) and the in situ IPCE techniques to determine the relation between solar cell performance and solar cell stability.

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We report on a sol-gel-based technique to fabricate MoO(3) thin films as a hole-injection layer for solution-processed or thermally evaporated organic solar cells. The solution-processed MoO(3) (sMoO(3)) films are demonstrated to have equal performance to hole-injection layers composed of either PEDOT:PSS or thermally evaporated MoO(3) (eMoO(3)), and the annealing temperature at which the sol-gel layer begins to work is consistent with the thermodynamic analysis of the process. Finally, the shelf lifetime of devices made with the sMoO(3) is similar to equivalent devices prepared with a eMoO(3) hole-injection layer.

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