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Madīnat Sittah Uktūbar, Egypt

Ayad M.A.,American University in Cairo | Obayya S.S.A.,Center for Photonic and Smart Materials | Swillam M.A.,American University in Cairo
Journal of Optics (United Kingdom) | Year: 2015

An efficient sensitivity analysis approach for quantum nanostructures is proposed. The imaginary time propagation method (ITP) is utilized to solve the time dependent Schrödinger equation (TDSE). Using this method, an extraction of all the modes and their sensitivity with respect to all the design parameters have been performed with minimal computational effort. The sensitivity analysis is done using the adjoint variable method (AVM) and results are comparable to those obtained using central finite difference method (CFD) applied directly on the response level. © 2016 IOP Publishing Ltd. Source


Mohamed S.A.,Johannes Kepler University | Mohamed S.A.,Center for Photonic and Smart Materials | Mohamed S.A.,Benha University | Gasiorowski J.,Johannes Kepler University | And 9 more authors.
Solar Energy Materials and Solar Cells | Year: 2015

An important issue in construction of organic photovoltaic cells concerns the selective contacts. Here, especially the modification of the hole-extraction is challenging, as energy levels have to match the polymer's highest occupied molecular orbital (HOMO). We took the view to the mutual anode interface and we sought for a solution-based alternative for commonly used PEDOT:PSS - with an eye on improving the hole-extraction with an inorganic interlayer. We present copper iodide (CuI) as a versatile inorganic p-type semiconductor that meets the requirements for enhanced charge extraction in donor polymers. We applied two types of anthracene-containing PPE-PPV block-copolymers that recently gained attention as efficient active absorbers in bulk heterojunction photovoltaic cells. We report on the advantages using CuI as hole-selective contact and show an improvement of the power conversion efficiency in polymer-based solar cells. © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. Source


Stadler P.,Johannes Kepler University | Mohamed S.A.,Johannes Kepler University | Mohamed S.A.,Benha University | Mohamed S.A.,Center for Photonic and Smart Materials | And 13 more authors.
Advanced Materials | Year: 2015

(Graph Presented) Lead sulfide quantum dots represent an emerging photovoltaic absorber material. While their associated optical qualities are true for the colloidal solution phase, they change upon processing into thin-films. A detailed view to the optical key-parameters during solid-film development is presented and the limits and outlooks for this versatile and promising absorber are discussed. Copyright © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. Source

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