Contactless Spatially Resolved Measurement of Bulk Free-Carrier Lifetime in Silicon Ingots

1986 ◽  
Vol 69 ◽  
Author(s):  
S. M. Johnson ◽  
L. G. Johnson ◽  
R. Hemphill
Keyword(s):  
Spatial Dependence ◽  
Polycrystalline Silicon ◽  
Carrier Lifetime ◽  
Transient Absorption ◽  
Free Carrier ◽  
Large Area ◽  
Spatially Resolved ◽  
Probe Transmission ◽  
Transmission Measurements ◽  
Absorption Measurements

AbstractA contactless spatially resolved measurement of bulk free-carrier lifetime in polycrystalline silicon ingots was accomplished using optically modulated free-carrier infrared absorption. Using a CW Nd:YAG laser (λ = 1.319 μm) for a probe and novel pulsed, tunable, infrared dye laser (λ = 1.10 to 1.13 μm) with photon energies near the Si bandgap, for a pump, the free-carrier lifetime was determined from transient absorption measurements to a maximum depth of 3.0 cm from the surface of an ingot. The spatial dependence of the free-carrier lifetime and the distribution of precipitates (determined from infrared probe transmission measurements) measured along the growth axis of an ingot were found to be strongly related to the spatial dependence of the I–V characteristics of large area solar cells fabricated from the subsequently wafered ingot.

Carrier Lifetime Analysis by Photoconductance Decay and Free Carrier Absorption Measurements

2001 ◽  
Vol 148 (11) ◽  
pp. G655 ◽  
Author(s):  
H.-J. Schulze ◽  
A. Frohnmeyer ◽  
F.-J. Niedernostheide ◽  
F. Hille ◽  
P. Tütto ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Free Carrier ◽  
Free Carrier Absorption ◽  
Lifetime Analysis ◽  
Carrier Absorption ◽  
Absorption Measurements

Correlation of Fe-Rich Defect Centre and Minority Carrier Lifetime in p-Type Multicrystalline Silicon

2013 ◽  
Vol 440 ◽  
pp. 82-87 ◽  
Author(s):  
Mohammad Jahangir Alam ◽  
Mohammad Ziaur Rahman
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Multicrystalline Silicon ◽  
Recombination Lifetime ◽  
Spatially Resolved ◽  
Carrier Recombination ◽  
Negative Role ◽  
P Type ◽  
The Impact

A comparative study has been made to analyze the impact of interstitial iron in minority carrier lifetime of multicrystalline silicon (mc-Si). It is shown that iron plays a negative role and is considered very detrimental for minority carrier recombination lifetime. The analytical results of this study are aligned with the spatially resolved imaging analysis of iron rich mc-Si.

scholarly journals Dynamics of Strong Coupling Between Free Charge Carriers in Organometal Halide Perovskites and Aluminum Plasmonic States

2022 ◽  
Vol 9 ◽  
Author(s):  
Yang Luo ◽  
Hai Wang ◽  
Le-Yi Zhao ◽  
Yong-Lai Zhang
Keyword(s):  
Strong Coupling ◽  
Transient Absorption ◽  
Perovskite Solar Cells ◽  
Coupled System ◽  
Free Carrier ◽  
Charge Carriers ◽  
Free Charge ◽  
Free Carriers ◽  
Halide Perovskites ◽  
Poor Absorption

We have investigated a strong coupled system composed of a MAPbIxCl3-x perovskite film and aluminum conical nanopits array. The hybrid states formed by surface plasmons and free carriers, rather than the traditional excitons, is observed in both steady-state reflection measurements and transient absorption spectra. In particular, under near upper band resonant excitation, the bleaching signal from the band edge of uncoupled perovskite was completely separated into two distinctive bleaching signals of the hybrid system, which is clear evidence for the formation of strong coupling states between the free carrier–plasmon state. Besides this, a Rabi splitting up to 260 meV is achieved. The appearance of the lower bands can compensate for the poor absorption of the perovskite in the NIR region. Finally, we found that the lifetime of the free carrier–SP hybrid states is slightly shorter than that of uncoupled perovskite film, which can be caused by the ultrafast damping of the SPs modes. These peculiar features on the strong coupled hybrid states based on free charge carriers can open new perspectives for novel plasmonic perovskite solar cells.

Unusually Strong Bi-Exciton Repulsion Detected in Quantum Confined CsPbBr3 Nanocrystals with Two and Three Pulse Femtosecond Spectroscopy

2021 ◽  
Author(s):  
jayanta dana ◽  
Tal Binyamin ◽  
Lioz Etgar ◽  
Sanford Ruhman
Keyword(s):  
Cross Section ◽  
Quantum Confinement ◽  
Auger Recombination ◽  
Transient Absorption ◽  
Stimulated Emission ◽  
Band Edge ◽  
High Time Resolution ◽  
Difference Spectra ◽  
The Difference ◽  
Absorption Measurements

Transient absorption measurements were conducted on pristine and on monoexciton saturated<br>CsPbBr3 nanocrystals varying in size within the regime of strong quantum confinement. Once<br>the difference spectra were translated to absolute transient changes in absorption cross section,<br>a single exciton is shown to completely bleach the band edge absorption peak, and induce a<br>new absorption roughly two times weaker ~100 meV to the blue. Difference spectra obtained<br>during Auger recombination of biexcitons demonstrate that addition of a second exciton, rather<br>than double the effect of a first, bleaches the blue induced absorption band without producing<br>net stimulated emission at the band edge. Accompanied by high time resolution transient<br>absorption spectra pumping at the lowest exciton band, these results identify the blue induced<br>absorption as the second transition to 1Se1Sh which is shifted in energy due to unusually strong<br>and promptly rising biexciton repulsion. <br>

scholarly journals Exciton dynamics in DNA oligomers studied by broadband deep-UV transient absorption spectroscopy

2019 ◽  
Vol 205 ◽  
pp. 10006
Author(s):  
Benjamin Bauer ◽  
Malte Oppermann ◽  
Majed Chergui
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Base Stacking ◽  
Dna Oligomers ◽  
Exciton Dynamics ◽  
Deep Uv ◽  
Strand Length ◽  
Absorption Measurements

We report broadband transient absorption measurements of adenine strands in the deep-UV (250-370 nm). By varying the strand length we resolve the interplay between inter-base stacking and exciton formation and dynamics in DNA oligomers.

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