Progress in Photovoltaics: Research and Applications

Cover image for Vol. 19 Issue 6

September 2011

Volume 19, Issue 6

Pages 631–756

  1. Research Articles

    1. Top of page
    2. Research Articles
    3. Research: Short Communication: Accelerated Publications
    4. Applications
    5. Literature Survey
    1. Efficient light trapping in silicon solar cells by ultrafast-laser-induced self-assembled micro/nano structures (pages 631–639)

      Barada K. Nayak, Vikram V. Iyengar and Mool C. Gupta

      Version of Record online: 5 JAN 2011 | DOI: 10.1002/pip.1067

      Thumbnail image of graphical abstract

      A novel ultrafast laser processing technique is used to create self-assembled micro/nano structures on crystalline and multi-crystalline silicon surfaces for efficient light trapping. Light reflection (including scattering) of the Si surface has been reduced to less than 3% for the entire solar spectrum and the material appears completely black to the naked eye. We report for the first time the total solar cell efficiency of over 14% fabricated on the ultrafast-laser-induced micro/nano structured crystalline Si wafer.

    2. Effects of spectrum on the power rating of amorphous silicon photovoltaic devices (pages 640–648)

      C. Monokroussos, M. Bliss, Y.N. Qiu, C.J. Hibberd, T.R. Betts, A.N. Tiwari and R. Gottschalg

      Version of Record online: 19 JAN 2011 | DOI: 10.1002/pip.1080

      Thumbnail image of graphical abstract

      Variation of the mismatch factor M for the case of the 400nm cell in the as prepared (a) and degraded (b) state. The x-axis represents here the voltage normalized by the VOC value of the cell under STCs. It is shown in this paper that the device state affects the magnitude of the errors arising from spectral mismatch. The simulated errors are dependent on the level of degradation, but also the i-layer thickness of the a-Si:H device.

    3. Interstitial iron concentrations across multicrystalline silicon wafers via photoluminescence imaging (pages 649–657)

      AnYao Liu, Yang-Chieh Fan and Daniel Macdonald

      Version of Record online: 5 JAN 2011 | DOI: 10.1002/pip.1082

      Thumbnail image of graphical abstract

      We present high-resolution images of the lateral distribution of interstitial iron across wafers from various positions along the length of a directionally solidified multicrystalline silicon ingot. The iron images reveal the internal gettering of iron during ingot cooling to grain boundaries and dislocation clusters, resulting in much lower dissolved iron concentrations at those features. In contrast, gettered wafers exhibit higher interstitial iron concentrations at the crystallographic defects than within the grains.

    4. Analysis of degradation mechanisms of crystalline silicon PV modules after 12 years of operation in Southern Europe (pages 658–666)

      Paula Sánchez-Friera, Michel Piliougine, Javier Peláez, Jesús Carretero and Mariano Sidrach de Cardona

      Version of Record online: 5 JAN 2011 | DOI: 10.1002/pip.1083

      Thumbnail image of graphical abstract

      This paper presents the results of the investigations carried out on the degradation mechanisms of a crystalline silicon PV installation of 2kWp after 12 years of exposure in Málaga, Spain. The analysis was conducted by visual inspection, infrared thermography and electrical performance evaluation. The total peak power loss, including the initial light induced degradation, was 11.5%, which corresponded almost totally to a loss in short-circuit current.

    5. Derivation of power gain for three types of three dimensional photovoltaics cells (pages 667–675)

      Jack Flicker and Jud Ready

      Version of Record online: 28 FEB 2011 | DOI: 10.1002/pip.1084

      Thumbnail image of graphical abstract

      In order to determine how to optimize geometrical layout of 3D cells to maximize the average number of interactions between a photon and the solar cell surface, G, theoretical equations were developed for three different configurations, a single infinite trench, a constrained box, and an infinite 2D array of square towers. To evaluate these expressions, monte carlo simulations were carried out for all three morphologies. The theoretical expressions describe simulated data very well for all configurations.

    6. Upper limits to absorption enhancement in thick solar cells using diffraction gratings (pages 676–687)

      A. Mellor, I. Tobías, A. Martí, M.J. Mendes and A. Luque

      Version of Record online: 5 JAN 2011 | DOI: 10.1002/pip.1086

      Thumbnail image of graphical abstract

      In this paper a mathematical formalism is derived for calculating the absorption that can be expected in a thick solar cell equipped with a diffraction grating, which can be applied to any lattice geometry and grating profile. The formalism is used to calculate the upper limit of total absorption that can theoretically be achieved using a diffraction grating. The upper limit is shown to be equal to the overall thermodynamic limit of 1−exp(−4n2αw/sin2θ0) for all cell absorbances and concentration factors

    7. Measurement and simulation of vibrations of PV-modules induced by dynamic mechanical loads (pages 688–694)

      Marcus Assmus, Steffen Jack, Karl-Anders Weiss and Michael Koehl

      Version of Record online: 23 FEB 2011 | DOI: 10.1002/pip.1087

      Thumbnail image of graphical abstract

      Photovoltaic-modules are exposed to external mechanical loads. The graphic shows a schematic representation of a free standing module in the air flow with positive (front) and negative pressure range (back) as well as resulting movement (arrow) due to flow separation.

    8. Structural inhomogeneities in polycrystalline silicon on glass solar cells and their effects on device characteristics (pages 695–705)

      J. Wong, J. L. Huang, S. Varlamov, M. A. Green, R. Evans, M. Keevers and R. J. Egan

      Version of Record online: 12 JAN 2011 | DOI: 10.1002/pip.1089

      Thumbnail image of graphical abstract

      This article demonstrates experimentally and analyses the detriments of potential fluctuations in polycrystalline silicon on glass solar cells, namely in terms of the open circuit voltage and fill factor. Electrostatic fluctuations arise from charged extended defects and are influential to the cell voltage properties as the absorber dopant concentration falls below a certain threshold (a few 1015cm-3). Bandgap fluctuations on the other hand can be detrimental to the open circuit voltage of electron-beam evaporated cells of any absorber dopant density.

    9. Progress with epitaxy wrap-through crystalline silicon thin-film solar cells (pages 706–714)

      Emily J. Mitchell, Nils Brinkmann and Stefan Reber

      Version of Record online: 28 FEB 2011 | DOI: 10.1002/pip.1091

      Thumbnail image of graphical abstract

      The Epitaxy Wrap-Through cell is a back contact crystalline silicon epitaxial thin-film solar cell. An ‘pitaxy-through-holes’ process has been developed and various configurations of the cell have been investigated. The best result so far, with a 22 µm base layer and a passivated selective emitter, is 13.2% efficiency.

    10. Use of seed layers for structure, optical, and electronic transport measurements on microcrystalline silicon on glass (pages 715–723)

      C. Ross, Y. Mai, R. Carius and F. Finger

      Version of Record online: 13 MAY 2011 | DOI: 10.1002/pip.1093

      Thumbnail image of graphical abstract

      The benefits of thin undoped ‘seed layers’ for the preparation of microcrystalline silicon on glass for material characterization are demonstrated. A detailed structural analysis on the base of Raman spectroscopy and photothermal deflection spectroscopy reveals that ‘seed layers’ are not only effective for the growth of structurally homogenous films and for an extension of the range of deposition parameters in which highly crystalline material is grown, but also allow for preparing material on glass with properties very close to that of functional layers in thin film solar cells. Films which have successfully been tailored in this way are characterized with respect to electrical conductivity and optical absorption.

    11. Ray tracing for the optics at nano-textured ZnO–air and ZnO–silicon interfaces (pages 724–732)

      Melanie Schulte, Karsten Bittkau, Bart Elger Pieters, Silvia Jorke, Helmut Stiebig, Jürgen Hüpkes and Uwe Rau

      Version of Record online: 23 FEB 2011 | DOI: 10.1002/pip.1097

      Thumbnail image of graphical abstract

      The scattering behavior of nano-textured ZnO-Air and ZnO-Silicon interfaces is investigated by a ray tracing approach. The approach is examined by means of a SNOM experiment on one hand and the numerical solution of Maxwell's equations on the other hand. We show, that ray tracing describes dominant features of the local scattering properties.

  2. Research: Short Communication: Accelerated Publications

    1. Top of page
    2. Research Articles
    3. Research: Short Communication: Accelerated Publications
    4. Applications
    5. Literature Survey
    1. Spatially separated atomic layer deposition of Al2O3, a new option for high-throughput Si solar cell passivation (pages 733–739)

      B. Vermang, A. Rothschild, A. Racz, J. John, J. Poortmans, R. Mertens, P. Poodt, V. Tiba and F. Roozeboom

      Version of Record online: 23 FEB 2011 | DOI: 10.1002/pip.1092

      Thumbnail image of graphical abstract

      The passivation quality and uniformity of spatially separated ALD Al2O3 films are evaluated and compared to conventional temporal ALD Al2O3. On p-type Si, 10 and 30 nm spatial ALD Al2O3 layers can achieve the same level of surface passivation as equivalent temporal ALD layers. On n-type Si, after “firing”, 30 nm of spatially separated ALD Al2O3 can lead to effective surface recombination velocities as low as 2.9  cm/s, compared to 1.9  cm/s in the case of temporal ALD Al2O3.

  3. Applications

    1. Top of page
    2. Research Articles
    3. Research: Short Communication: Accelerated Publications
    4. Applications
    5. Literature Survey
    1. Method of analyzing silicon groove damage using QSS-PC, PL imaging, silicon etch rate, and visual microscopy for solar cell fabrication (pages 740–746)

      Kean Chern Fong and Andrew Blakers

      Version of Record online: 15 JUL 2011 | DOI: 10.1002/pip.1081

      Thumbnail image of graphical abstract

      The paper presents a method of groove damage analysis using a combination of four sample characterization tools. The presented method allows determination of the damage radius of the grooves within the bulk of the wafer, the radius of damage in the dielectric layer, as well as the groove etching requirements to fully recover the minority carrier lifetime in the vicinity of the groove. Application of this method to two different silicon grooving method is demonstrated.

    2. Tracking and back-tracking (pages 747–753)

      E. Lorenzo, L. Narvarte and J. Muñoz

      Version of Record online: 23 FEB 2011 | DOI: 10.1002/pip.1085

      Thumbnail image of graphical abstract

      This paper presents a review of back-tracking geometry not only for single axis but also for two-axis tracking and analyses the corresponding energy gains. It compares the different back-tracking strategies with the ideal tracking in terms of energy yield concluding, on the one hand, that back-tracking is more useful for single horizontal axis than for the single vertical one, and on the other hand, that back-tracking is more efficient when applied in the primary axis of a two-axis tracker.

  4. Literature Survey

    1. Top of page
    2. Research Articles
    3. Research: Short Communication: Accelerated Publications
    4. Applications
    5. Literature Survey
    1. Photovoltaics literature survey (no. 88) (pages 754–756)

      Santosh Shrestha

      Version of Record online: 24 AUG 2011 | DOI: 10.1002/pip.1165

SEARCH

SEARCH BY CITATION