Solar photovoltaics is ready to power a sustainable future

Reliability of IR-imaging of PV-plants under operating conditions

Recent technical advancements, economics and environmental impacts of floating photovoltaic solar energy conversion systems

Defect detection of solar cells in electroluminescence images using Fourier image reconstruction

Photoluminescence Imaging for Photovoltaic Applications

Implementation of agrophotovoltaics: Techno-economic analysis of the price-performance ratio and its policy implications

We introduce a fast and easy to apply method for determining the local series resistance of standard silicon solar cells. For this method only two electroluminescence images taken at different voltages are needed. From these two images, the local voltage and the local current density through the device can be calculated. Knowing these parameters for each pixel yields the local series resistance. By calculating the cell's dark saturation current from the lower voltage image, the method also works with multicrystalline material. We show images, acquired in only 300 ms and compare them with other luminescence based series resistance images. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Fast series resistance imaging for silicon solar cells using electroluminescence

Quality control of as-cut multicrystalline silicon wafers using photoluminescence imaging for solar cell production

Metallic impurities are detrimental to many silicon devices and limit the efficiency of multicrystalline silicon solar cells. Therefore they are a major subject of ongoing research. Photoluminescence spectroscopy is a promising technique for detecting precipitated metals in silicon because of its sensitivity to the minority carrier density and to specific types of defects; however the impact of impurities on the defect luminescence could not be clarified yet. In this letter we examine the role of micron-sized iron and copper precipitates in direct bonded wafers by micro-photoluminescence spectroscopy. Both kinds of precipitates are detectable by means of the reduced band-to-band luminescence. An element-specific effect on the defect luminescence is observed. The results are confirmed by X-ray fluorescence spectroscopy. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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Micro-photoluminescence spectroscopy on metal precipitates in silicon

Synchrotron based X-ray excited optical luminescence (XEOL) has been measured with many direct bandgap semiconductors. We present XEOL measurements on crystalline silicon (Si), obtained despite of its indirect bandgap and the consequently low luminescence efficiency. Spectra of monocrystalline and multicrystalline (mc) Si at room temperature are compared to theoretical spectra. A possible application in the synchrotron-based research on mc-Si is exemplified by combining XEOL, X-ray fluorescence (XRF) spectroscopy, photoluminescence (PL) spectroscopy, and microscope images of grain boundaries. This approach can be utilized to investigate the recombination activity of metal precipitates, to analyze areas of different lifetimes on mc-Si samples and to correlate additional material parameters to XRF measurements. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Eicke R. Weber

Papers

Implementation of agrophotovoltaics: Techno-economic analysis of the price-performance ratio and its policy implications

Fast series resistance imaging for silicon solar cells using electroluminescence

Quality control of as-cut multicrystalline silicon wafers using photoluminescence imaging for solar cell production

Micro-photoluminescence spectroscopy on metal precipitates in silicon

X-ray excited optical luminescence from crystalline silicon