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Micro-spectroscopy on silicon wafers and solar cells.

Gundel P, Schubert MC, Heinz FD, Woehl R, Benick J, Giesecke JA, Suwito D, Warta W - Nanoscale Res Lett (2011)

Bottom Line: This is demonstrated on micro defects in multicrystalline silicon.In comparison with the stress measurement by μRS, these measurements reveal the influence of stress on the recombination activity of metal precipitates.With the aim of evaluating technological process steps, Fano resonances in μRS measurements are analyzed for the determination of the doping density and the carrier lifetime in selective emitters, laser fired doping structures, and back surface fields, while μPLS can show the micron-sized damage induced by the respective processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstr, 2, 79110 Freiburg, Germany. paul.gundel@ise.fraunhofer.de.

ABSTRACT
Micro-Raman (μRS) and micro-photoluminescence spectroscopy (μPLS) are demonstrated as valuable characterization techniques for fundamental research on silicon as well as for technological issues in the photovoltaic production. We measure the quantitative carrier recombination lifetime and the doping density with submicron resolution by μPLS and μRS. μPLS utilizes the carrier diffusion from a point excitation source and μRS the hole density-dependent Fano resonances of the first order Raman peak. This is demonstrated on micro defects in multicrystalline silicon. In comparison with the stress measurement by μRS, these measurements reveal the influence of stress on the recombination activity of metal precipitates. This can be attributed to the strong stress dependence of the carrier mobility (piezoresistance) of silicon. With the aim of evaluating technological process steps, Fano resonances in μRS measurements are analyzed for the determination of the doping density and the carrier lifetime in selective emitters, laser fired doping structures, and back surface fields, while μPLS can show the micron-sized damage induced by the respective processes.

No MeSH data available.


Related in: MedlinePlus

Graphic representation of calibration table. Graphic representation of a part of the calibration table for a 1.5 × 1016-cm-3 p-doped sample with different surface recombination velocities. From the ratio Q, which is monotonically increasing with the Shockley-Read-Hall lifetime τSRH, we can directly determine τSRH. In analogy to this calibration table, a table for the determination of the doping density can be plotted
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Figure 3: Graphic representation of calibration table. Graphic representation of a part of the calibration table for a 1.5 × 1016-cm-3 p-doped sample with different surface recombination velocities. From the ratio Q, which is monotonically increasing with the Shockley-Read-Hall lifetime τSRH, we can directly determine τSRH. In analogy to this calibration table, a table for the determination of the doping density can be plotted

Mentions: By this comparison, the Shockley-Read-Hall lifetime and the doping density can be extracted. An example for the simulated injection density in the sample and a graphic representation of a part of the calibration table for the lifetime are shown in Figures 2 and 3.


Micro-spectroscopy on silicon wafers and solar cells.

Gundel P, Schubert MC, Heinz FD, Woehl R, Benick J, Giesecke JA, Suwito D, Warta W - Nanoscale Res Lett (2011)

Graphic representation of calibration table. Graphic representation of a part of the calibration table for a 1.5 × 1016-cm-3 p-doped sample with different surface recombination velocities. From the ratio Q, which is monotonically increasing with the Shockley-Read-Hall lifetime τSRH, we can directly determine τSRH. In analogy to this calibration table, a table for the determination of the doping density can be plotted
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211253&req=5

Figure 3: Graphic representation of calibration table. Graphic representation of a part of the calibration table for a 1.5 × 1016-cm-3 p-doped sample with different surface recombination velocities. From the ratio Q, which is monotonically increasing with the Shockley-Read-Hall lifetime τSRH, we can directly determine τSRH. In analogy to this calibration table, a table for the determination of the doping density can be plotted
Mentions: By this comparison, the Shockley-Read-Hall lifetime and the doping density can be extracted. An example for the simulated injection density in the sample and a graphic representation of a part of the calibration table for the lifetime are shown in Figures 2 and 3.

Bottom Line: This is demonstrated on micro defects in multicrystalline silicon.In comparison with the stress measurement by μRS, these measurements reveal the influence of stress on the recombination activity of metal precipitates.With the aim of evaluating technological process steps, Fano resonances in μRS measurements are analyzed for the determination of the doping density and the carrier lifetime in selective emitters, laser fired doping structures, and back surface fields, while μPLS can show the micron-sized damage induced by the respective processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstr, 2, 79110 Freiburg, Germany. paul.gundel@ise.fraunhofer.de.

ABSTRACT
Micro-Raman (μRS) and micro-photoluminescence spectroscopy (μPLS) are demonstrated as valuable characterization techniques for fundamental research on silicon as well as for technological issues in the photovoltaic production. We measure the quantitative carrier recombination lifetime and the doping density with submicron resolution by μPLS and μRS. μPLS utilizes the carrier diffusion from a point excitation source and μRS the hole density-dependent Fano resonances of the first order Raman peak. This is demonstrated on micro defects in multicrystalline silicon. In comparison with the stress measurement by μRS, these measurements reveal the influence of stress on the recombination activity of metal precipitates. This can be attributed to the strong stress dependence of the carrier mobility (piezoresistance) of silicon. With the aim of evaluating technological process steps, Fano resonances in μRS measurements are analyzed for the determination of the doping density and the carrier lifetime in selective emitters, laser fired doping structures, and back surface fields, while μPLS can show the micron-sized damage induced by the respective processes.

No MeSH data available.


Related in: MedlinePlus