Quantitative Raman Scattering from Acceptors in GaAs

1987 ◽  
Vol 104 ◽  
Author(s):  
T. D. Harrisz ◽  
M. G. Lamont ◽  
L. Seibles
Keyword(s):  
Raman Scattering ◽  
Laser Power ◽  
Laser Wavelength ◽  
Dye Laser ◽  
Local Mode ◽  
Tunable Dye Laser ◽  
Electronic Raman Scattering ◽  
Ccd Detector ◽  
Cooled Ccd ◽  
Carbon Concentrations

ABSTRACTRecent reports have demonstrated the possibility of probing acceptor concentrations in bulk semi-insulating GaAs by electronic Raman scattering using 1.06 μm radiation.1 The inefficiency of detectors in this spectral region severely limits sensitivity, precluding extension to epitaxial layers. We will discuss an approach using both 1.06 μm radiation to photo-neutralize acceptors, and a tunable dye laser to excite Raman scattering. Using a cooled CCD detector, an improvement in detection limit of 104 is realized. Comparison of Raman signals with infrared local mode measurements for samples with carbon concentrations from 1×1014 to 4×1015 cm-3 will be reported. The effect of 1.06 μm power density, dye laser wavelength, dye laser power, and sample fluorescence are included.

Optical Characterization of SiC Wafers

1999 ◽  
Vol 572 ◽  
Author(s):  
J. C. Burton ◽  
M. Pophristic ◽  
F. H. Long ◽  
I. Ferguson
Keyword(s):  
Raman Spectroscopy ◽  
Raman Scattering ◽  
Laser Wavelength ◽  
Time Resolved ◽  
Near Ir ◽  
Electronic Raman Scattering ◽  
Defect Levels ◽  
Sic Wafer ◽  
Time Resolved Photoluminescence

ABSTRACTRaman spectroscopy has been used to investigate wafers of both 4H-SiC and 6H-SiC. The two-phonon Raman spectra from both 4H- and 6H-SiC have been measured and found to be polytype dependent, consistent with changes in the vibrational density of states. We have observed electronic Raman scattering from nitrogen defect levels in both 4H- and 6H-SiC at room temperature. We have found that electronic Raman scattering from the nitrogen defect levels is significantly enhanced with excitation by red or near IR laser light. These results demonstrate that the laser wavelength is a key parameter in the characterization of SiC by Raman scattering. These results suggest that Raman spectroscopy can be used as a noninvasive, in situ diagnostic for SiC wafer production and substrate evaluation. We also present results on time-resolved photoluminescence spectra of n-type SiC wafers.

TUNABLE DYE LASER INSTRUMENT FOR OPHTHALMOLOGY

1987 ◽  
Vol 48 (C7) ◽  
pp. C7-303-C7-303
Author(s):  
M. L. PASCU ◽  
A. PASCU ◽  
M. ENESCU ◽  
M. OLTEANU ◽  
B. CÂRSTOCEA
Keyword(s):  
Dye Laser ◽  
Tunable Dye Laser

scholarly journals Electronic Raman Scattering in Suspended Semiconducting Carbon Nanotube

2020 ◽  
Vol 11 (24) ◽  
pp. 10497-10503
Author(s):  
Yuecong Hu ◽  
Shaochuang Chen ◽  
Xin Cong ◽  
Sida Sun ◽  
Jiang-bin Wu ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Raman Scattering ◽  
Electronic Raman Scattering
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