Characterization of multicrystalline silicon wafers by non-invasive measurements

Kunst, M.; Grunow, P.

doi:10.1016/j.solmat.2004.01.034

Cited by 8 publications

(5 citation statements)

References 13 publications

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“…The best fit gives D ) 20 cm 2 /s at the fluence used if diffusion is to regions outside the electron zone area; if within, D becomes much less in magnitude (0.2-2 cm 2 /s). The obtained values are significantly larger than that of heat diffusion in VO 2 (D heat ≈ 0.02 cm 2 /s 15,19 ) but close to the carrier diffusion value we calculated from mobility measurements (D ∼ 0.2 cm 2 / s 15 ); for semiconductors, 22 D reaches about 20 cm 2 /s, while for metals, say, gold, D ∼150 cm 2 /s. 23 We note that the diffusion in 2D gives dependence (t -1 ) that is different from that of one-dimensional (1D) (t -1/2 ) or three-dimensional (3D) (t -3/2 ) diffusion.…”

Section: ∂ ∂Tsupporting

confidence: 83%

Ultrafast Electron Microscopy (UEM): Four-Dimensional Imaging and Diffraction of Nanostructures during Phase Transitions

et al. 2007

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Four-dimensional (4D) imaging during structural changes are reported here using ultrafast electron microscopy (UEM). For nanostructures, the phase transition in the strongly correlated material vanadium dioxide is our case study. The transition is initiated and probed in situ, in the microscope, by a femtosecond near-infrared and electron pulses (at 120 keV). Real-space imaging and Fourier-space diffraction patterns show that the transition from the monoclinic (P21/c) to tetragonal (P42/mnm) structure is induced in 3 +/- 1 ps, but there exists a nonequilibrium (metastable) structure whose nature is determined by electronic, carrier-induced, structural changes. For the particles studied, the subsequent recovery occurs in about 1 ns. Because of the selectivity of excitation from the 3d parallel-band, and the relatively low fluence used, these results show the critical role of carriers in weakening the V4+-V4+ bonding in the monoclinic phase and the origin of the nonequilibrium phase. A theoretical two-dimensional (2D) diffusion model for nanoscale materials is presented, and its results account for the observed behavior.

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Section: ∂ ∂Tsupporting

confidence: 83%

Ultrafast Electron Microscopy (UEM): Four-Dimensional Imaging and Diffraction of Nanostructures during Phase Transitions

et al. 2007

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“…Regarding the solar cell production, there is a strong need for noninvasive, low-cost and fast production monitoring tools. For the incoming wafer inspection and for the in-situ process evaluation microwave reflection based techniques are widely used [10,11] but also finished solar cell inspection tools, going beyond the standard IV-light and quantum yield measurements, become more and more important. Cooled CCD-camera based defect characterization by room temperature luminescence, as it has been for example regularly used for fiber-optic component defect analysis [12,13] has recently been demonstrated to be feasible also for crystalline silicon solar cell inspection [14,15].…”

Section: Introductionmentioning

confidence: 99%

Electroluminescence efficiency degradation of crystalline silicon solar cells after irradiation with protons in the energy range between 0.8 MeV and 65 MeV

Neitzert¹,

Ferrara

Kunst

et al. 2008

Physica Status Solidi (b)

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Standard crystalline silicon homojunction solar cells have been irradiated with high energy protons at variable energies between 0.8 MeV and 65 MeV. As one possible criterion for the evaluation of the radiation induced degradation, we compared the supression of the bandgap electroluminescence at a wavelength around 1150 nm for the solar cells, irradiated at different energies. The lowest electroluminescene efficiency has been observed for an intermediate proton energy of 1.7 MeV. At this energy value however crystalline silicon solar cells are not homogeneously damaged as shown by the defect profiles, calculated by the SRIM code. We propose therefore a irradiation at a high energy in order to obtain a relative homogeneous defect profile. At 65 MeV the projected range of the protons in silicon is about 2 cm and we obtain a nearly constant defect distribution in the solar cell and the irradiation can be performed in air. Subsequently we compared the fluence dependence of the degradation of the solar cell parameters after 65 MeV irradiation with other material by the quantum yield spectra and the effective excess charge carrier lifetime, as measured on silicon wafers by the contactless TRMC-technique. Similar degradation has been found for the short circuit current, solar cell efficiency and electroluminescence efficiency and a good agreement between diffusion length and excess charge carrier lifetime changes

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“…We proposed in a previous publication a procedure to determine the volume lifetime τ v for p mc-Si based on measurements of a large number of wafers from different producers [51]. It is convenient to summarize the results and conclusions of this work, because it may elucidate several important points that we believe are important for reliable measurements and interpretation of measurements:…”

Section: P-type Multicrystalline-silicon (P Mc-si) 521 the Determinmentioning

confidence: 99%

The determination of charge‐carrier lifetime in silicon

Klein

Wuensch

Kunst³

2008

Physica Status Solidi (b)

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In this study, we report on a novel composite membrane system for pH‐responsive controlled release, which is composed of a porous membrane with linear grafted, positively pH‐responsive polymeric gates acting as functional valves, and a crosslinked, negatively pH‐responsive hydrogel inside the reservoir working as a functional pumping element. The proposed system features a large responsive release rate that goes effectively beyond the limit of concentration‐driven diffusion due to the pumping effects of the negatively pH‐responsive hydrogel inside the reservoir. The pH‐responsive gating membranes were prepared by grafting poly(methacrylic acid) (PMAA) linear chains onto porous polyvinylidene fluoride (PVDF) membrane substrates using a plasma‐graft pore‐filling polymerization, and the crosslinked poly(N,N‐dimethylaminoethyl methacrylate) (PDM) hydrogels were synthesized by free radical polymerization. The volume phase‐transition characteristics of PMAA and PDM were opposite. The proposed system opens new doors for pH‐responsive “smart” or “intelligent” controlled‐release systems, which are highly attractive for drug‐delivery systems, chemical carriers, sensors, and so on.

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Characterization of multicrystalline silicon wafers by non-invasive measurements

Cited by 8 publications

References 13 publications

Ultrafast Electron Microscopy (UEM): Four-Dimensional Imaging and Diffraction of Nanostructures during Phase Transitions

Ultrafast Electron Microscopy (UEM): Four-Dimensional Imaging and Diffraction of Nanostructures during Phase Transitions

Electroluminescence efficiency degradation of crystalline silicon solar cells after irradiation with protons in the energy range between 0.8 MeV and 65 MeV

The determination of charge‐carrier lifetime in silicon

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