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Crystalline Silicon Solar Cells (crystalline + silicon_solar_cell)
Selected AbstractsUltra-thin silicon solar cell: Modelling and characterisationPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2008L. Danos Abstract An ultra-thin crystalline silicon solar cell with an active silicon layer of 200 nm has been fabricated and fully characterised electrically (I-V characteristic, spectral response) and optically (Variable Angle Spectroscopic Ellipsometry). Interference effects were observed in the spectral response of the cell due to multiple reflections from the layers within the cell. A mathematical model was developed to account for the different reflections and transmission within the cell which reproduced excellently the essential features of the experimental spectral response. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Experimental testing of a random medium optical model of porous silicon for photovoltaic applicationsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2001A. A. Abouelsaood We have developed a model for light propagation in porous silicon (PS) based on the theory of wave propagation in random media. The low porosity case is considered, with silicon being the host material assuming randomly distributed spherical voids as scattering particles. The specular and the diffuse part of the light could be determined and treated separately. The model is applied to the case in which porous silicon would be used as a diffuse back reflector in a thin-film crystalline silicon solar cell realized in an ultrathin (1,3,,m) epitaxially grown Si layer on PS. Three,layer structures (epi/PS/Si) have been fabricated by atmospheric pressure chemical vapor deposition (APCVD) of 150,1000 nm epitaxial silicon layers on silicon wafers of which 150,450 nm of the surface has been electrochemically etched. An excellent agreement is found between the experimentally measured reflection data in the 400,1000 nm wavelength range and those calculated using the proposed model. The values of the layer thickness agree, within a reasonable experimental error, with those obtained independently by cross,sectional transmission electron microscopy (XTEM) analysis. This provides an experimental verification of the random,medium approach to porous silicon in the low porosity case. The analysis shows that the epitaxial growth process has led to appreciable porosity decrease of an initially high,porosity layer from about 60% to 20,30%. Copyright © 2001 John Wiley & Sons, Ltd. [source] Spatially resolved contact-resistance measurements on crystalline silicon solar cellsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 12 2009Stefan Kontermann Abstract This paper demonstrates a method for quantitatively determining the spatially resolved contact resistance of silicon solar cells. Contact-resistance maps obtained by this technique on screen-printed industrial silicon solar cells are presented and discussed. Extending the contact-resistance map to a series-resistance map by adding contributions from the rear, bulk, emitter, and metallization shows this map to qualitatively agree well with photoluminescence (PL) series-resistance imaging. Compared to existing approaches, our technique enables the spatially resolved measurement of the contact resistance separately from any other series-resistance contributions. [source] Encapsulating Eu3+ complex doped layers to improve Si-based solar cell efficiencyPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 8 2009Alessia Le Donne Abstract This paper reports the electrical characterization of commercially available crystalline silicon solar cells encapsulated with poly-vinylacetate doped with different Eu3+ organic complexes. The inclusion of these complexes in the encapsulating matrix allows down-shifting of the solar spectrum components below 420,nm toward the maximum quantum efficiency of the solar cells. This effect has been proven under Air Mass 1·5 conditions (simulating terrestrial applications) where an increase of the total power delivered by the encapsulated cells has been observed. Moreover, this enhancement has been obtained using very low percentage by weight of organolanthanide dopants, allowing a reduction in the Watt peak price. At higher concentrations a strong quenching of the energy transfer from the organic antenna to the lanthanide ion has been observed. Copyright © 2009 John Wiley & Sons, Ltd. [source] Simulation and implementation of a porous silicon reflector for epitaxial silicon solar cellsPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 5 2008Filip Duerinckx Abstract One of the main challenges in the ongoing development of thin film crystalline silicon solar cells on a supporting silicon substrate is the implementation of a long-wavelength reflector at the interface between the epitaxial layer and the substrate. IMEC has developed such a reflector based on electrochemical anodization of silicon to create a multi-layer porous silicon stack with alternating high and low porosity layers. This innovation results in a 1,2% absolute increase in efficiency for screenprinted epitaxial cells with a record of 13·8%. To reach a better understanding of the reflector and to aid in its continued optimization, several extensive optical simulations have been performed using an in-house-developed optical software programme. This software is written as a Microsoft Excel workbook to make use of its user-friendliness and modular structure. It can handle up to 15 individual dielectric layers and is used to determine the influence of the number and the sequence of the layers on the internal reflection. A sensitivity analysis is also presented. A study of the angle at which the light strikes the reflector shows separate regions in the physical working of the reflector which include a region where the Bragg effect is dominant as well as a region where total internal reflection plays the largest role. The existence of these regions is proved using reflection measurements. Based on these findings, an estimate is made for the achievable current gain with an ideal reflector and the potential of epitaxial silicon solar cells is determined. Copyright © 2008 John Wiley & Sons, Ltd. [source] Limiting efficiency of crystalline silicon solar cells due to Coulomb-enhanced Auger recombinationPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 2 2003Mark J. Kerr Excitonic effects are known to enhance the rate of intrinsic recombination processes in crystalline silicon. New calculations for the limiting efficiency of silicon solar cells are presented here, based on a recent parameterization for the Coulomb-enhanced Auger recombination rate, which accounts for its dopant type and dopant density dependence at an arbitrary injection level. Radiative recombination has been included along with photon recycling effects modeled by three-dimensional ray tracing. A maximum cell efficiency of 29.05% has been calculated for a 90-,m-thick cell made from high resistivity silicon at 25°C. For 1,,,cm p -type silicon, the maximum efficiency reduces from 28.6% for a 55-,m-thick cell in the absence of surface recombination, down to 27.0% for a thickness in the range 300,500,,m when surface recombination limits the open-circuit voltage to 720,mV. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||