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De Haan, V. (author), Santbergen, R. (author), Tijssen, M. (author), Zeman, M. (author)A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach–Zehnder and Michelson–Morley interferometer. The response of the Mach–Zehnder interferometer is similar to the Sagnac interferometer. However, the Sagnac...journal article 2011
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Jarolimek, K. (author), De Groot, R.A. (author), De Wijs, G.A. (author), Zeman, M. (author)Quantum wells (QWs) are nanostructures consisting of alternating layers of a low and high band-gap semiconductor. The band gap of QWs can be tuned by changing the thickness of the low band-gap layer, due to quantum confinement effects. Although this principle is well established for crystalline materials, there is still controversy for QWs...journal article 2014
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Santbergen, R. (author), Smets, A.H.M. (author), Zeman, M. (author)We present a novel approach for modeling the reflectance, transmittance and absorption depth profile of thin-film multilayer structures such as solar cells. Our model is based on the net-radiation method adapted for coherent calculations and is highly flexible while using a simple algorithm. We demonstrate that as a result arbitrary multilayer...journal article 2013
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Schulte, M. (author), Bittkau, K. (author), Jäger, K. (author), Ermes, M. (author), Zeman, M. (author), Pieters, B.E. (author)Textured interfaces in thin-film silicon solar cells improve the efficiency by light scattering. A technique to get experimental access to the angular intensity distribution (AID) at textured interfaces of the transparent conductive oxide (TCO) and silicon is introduced. Measurements are performed on a sample with polished microcrystalline...journal article 2011
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Jarolimek, K. (author), De Groot, R.A. (author), De Wijs, G.A. (author), Zeman, M. (author)We present a theoretical study of hydrogenated amorphous silicon nitride (a-SiNx:H), with equal concentrations of Si and N atoms (x=1), for two considerably different densities (2.0 and 3.0?g/cm3). Densities and hydrogen concentration were chosen according to experimental data. Using first-principles molecular-dynamics within density-functional...journal article 2010
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Solntsev, S. (author), Zeman, M. (author)In thin-film silicon solar cells (TFSC) efficient light management is essential in order to increase energy conversion efficiency. The application of nano-scale periodic gratings (PG) is a promising method to enhance absorption in the absorber layers of TFSC since they can efficiently scatter the incident light. Carefully designed gratings give...journal article 2011
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- Nádazdy, V. (author), Zeman, M. (author) journal article 2004
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Deligiannis, D. (author), Alivizatos, S. (author), Ingenito, A. (author), Zhang, D. (author), Van Sebille, M. (author), Van Swaaij, R.A.C.M.M. (author), Zeman, M. (author)Silicon heterojunction (SHJ) solar cells constantly gain more attention due to their low cost and relatively high efficiency. An important aspect of these solar cells is the incorporation of intrinsic hydrogenated amorphous silicon (a-Si:H) layers at each side of the c-Si wafer, which has increased the efficiency potential due to the excellent...journal article 2014
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Tan, H. (author), Sivec, L. (author), Yan, B. (author), Santbergen, R. (author), Zeman, M. (author), Smets, A.H.M. (author)We show experimentally that the photocurrent of thin-film hydrogenated microcrystalline silicon (?c-Si:H) solar cells can be enhanced by 4.5?mA/cm2 with a plasmonic back reflector (BR). The light trapping performance is improved using plasmonic BR with broader angular scattering and lower parasitic absorption loss through tuning the size of...journal article 2013
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Selker, J.S. (author), Thévenaz, L. (author), Huwald, H. (author), Mallet, A. (author), Luxemburg, W.M.J. (author), Van de Giesen, N. (author), Stejskal, M. (author), Zeman, J. (author), Westhoff, M. (author), Parlange, M.B. (author)Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We discuss the spectrum of fiber-optic tools that may...journal article 2006
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Ingenito, A. (author), Ortiz Lizcano, J.C. (author), Luxembourg, S.L. (author), Santbergen, R. (author), Weeber, A. (author), Isabella, O. (author), Zeman, M. (author)At present, research in c-Si solar cells is focused on increasing the efficiency while reducing the amount of used materials. Since silicon wafer and metal contribute up to 50% to the cost of a module, it is crucial to reduce the amount of these materials to fabricate cost-effective modules. In particular, for reducing the consumption of metal,...journal article 2014
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Melskens, J. (author), Schnegg, A. (author), Baldansuren, A. (author), Lips, K. (author), Plokker, M.P. (author), Eijt, S.W.H. (author), Schut, H. (author), Fischer, M. (author), Zeman, M. (author), Smets, A.H.M. (author)The structural and electrical properties of metastable defects in various types of hydrogenated amorphous silicon have been studied using a powerful combination of continuous wave electron-paramagnetic resonance spectroscopy, electron spin echo (ESE) decay measurements, and Doppler broadening positron annihilation spectroscopy. The observed...journal article 2015
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Jäger, K. (author), Fischer, M. (author), Van Swaaij, R.A.C.M.M. (author), Zeman, M. (author)Thin-film silicon solar cells (TFSSC), which can be manufactured from abundant materials solely, contain nano-textured interfaces that scatter the incident light. We present an approximate very fast algorithm that allows optimizing the surface morphology of two-dimensional nano-textured interfaces. Optimized nano-textures scatter the light...journal article 2013
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Han, L. (author), Zeman, M. (author), Smets, A.H.M. (author)The growth mechanism of silicon nanocrystals (Si NCs) synthesized at a high rate by means of expanding thermal plasma chemical vapor deposition technique are studied in this letter. A bimodal Gaussian size distribution is revealed from the high-resolution transmission electron microscopy images, and routes to reduce the unwanted large Si NCs are...journal article 2015
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Jarolimek, K. (author), De Groot, R.A. (author), De Wijs, G.A. (author), Zeman, M. (author)We use a molecular-dynamics simulation within density-functional theory to prepare realistic structures of hydrogenated amorphous silicon. The procedure consists of heating a crystalline structure of Si64H8 to 2370 K, creating a liquid and subsequently cooling it down to room temperature. The effect of the cooling rate is examined. We prepared a...journal article 2009
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Zhang, D. (author), Tavakoliyaraki, A. (author), Wu, Y. (author), Van Swaaij, R.A.C.M.M. (author), Zeman, M. (author)Heterojunction silicon with intrinsic thin layer (HIT) solar cells that combine advanced thin-film hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si) technologies are promising because of the high performance at low cost. Due to the low conductivity of a-Si:H, indium tin oxide (ITO) needs to be used as a front contact layer...journal article 2011
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Klaver, A. (author), Nádady, V. (author), Zeman, M. (author), Swaaiij, R.A.C.M.M. (author)We present a study of changes in the defect density of states in hydrogenated amorphous silicon (a-Si:H) due to high-energy electron irradiation using charged deep-level transient spectroscopy. It was found that defect states near the conduction band were removed, while in other band gap regions the defect-state density increased. A similar...journal article 2006
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Pieters, B.E. (author), Stiebig, H. (author), Zeman, M. (author), Van Swaaij, R.A.C.M.M. (author)Microcrystalline silicon (?c-Si:H) is a promising material for application in multijunction thin-film solar cells. A detailed analysis of the optoelectronic properties is impeded by its complex microstructural properties. In this work we will focus on determining the mobility gap of ?c-Si:H material. Commonly a value of 1.1?eV is found, similar...journal article 2009
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Wank, M.A. (author), Van Swaaij, R.A.C.M.M. (author), Kudlacek, P. (author), Van de Sanden, M.C.M. (author), Zeman, M. (author)We have applied pulse-shaped biasing to the expanding thermal plasma deposition of hydrogenated amorphous silicon at substrate temperatures ? 200?°C and growth rates around 1 nm/s. Substrate voltage measurements and measurements with a retarding field energy analyzer demonstrate the achieved control over the ion energy distribution for...journal article 2010
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Demontis, V. (author), Sanna, C. (author), Melskens, J. (author), Santbergen, R. (author), Smets, A.H.M. (author), Damiano, A. (author), Zeman, M. (author)Thin oxide interlayers are commonly added to the back reflector of thin-film silicon solar cells to increase their current. To gain more insight in the enhancement mechanism, we tested different back reflector designs consisting of aluminium-doped zinc oxide (ZnO:Al) and/or hydrogenated silicon oxide (SiOx:H) interlayers with different metals ...journal article 2013