Measurement of optical absorption in single quantum wells using photothermal deflection spectroscopy

1985 ◽  
Vol 47 (6) ◽  
pp. 591-593 ◽  
Author(s):  
A. F. S. Penna ◽  
Jagdeep Shah ◽  
A. E. DiGiovanni ◽  
A. Y. Cho ◽  
A. C. Gossard
1998 ◽  
Vol 37 (Part 1, No. 3A) ◽  
pp. 745-752 ◽  
Author(s):  
O. Ambacher ◽  
D. Brunner ◽  
R. Dimitrov ◽  
M. Stutzmann ◽  
A. Sohmer ◽  
...  

1993 ◽  
Vol 333 ◽  
Author(s):  
James D. Rudnicki ◽  
Richard E. Russo

ABSTRACTPhotothermal Deflection Spectroscopy (PDS) has been applied to the study of uranium oxide electrochemistry. PDS measures the optical absorption of the sample surface and concentration gradients formed in the electrolyte. Both of these measurements are performed in situ under dynamic conditions. The combination of these two measurements provides information that can be used to infer the mechanism of the UO2 surface chemistry. These studies of the uranium dissolution mechanism are performed in pH 10.5 sodium sulfate electrolytes at 22°C. The electrolytes are free from oxygen, and complexing species. Our results suggest that dissolution of UO2 can occur at oxidizing potentials as low as -300 mV vs. saturated calomel electrode (SCE). The optical absorption and concentration gradient results provide evidence for a substantial surface change that occurs at an oxidation potential of +300 mV. The results show that the surface layer formed by this change dissolves slowly by a non-electrochemical reaction.


1991 ◽  
Vol 228 ◽  
Author(s):  
M. Sinclair ◽  
C. H. Seager ◽  
D. McBranch ◽  
A. J. Heeger ◽  
G. L. Baker

ABSTRACTAlong with χ(3), the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10-5, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of “transparent” materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly[1,4-phenylenevinylene] (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm-1 to 10 cm-1. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration or fluorination.


1993 ◽  
Vol 13 (3) ◽  
pp. 315 ◽  
Author(s):  
Joseph Micallef ◽  
E.Herbert Li ◽  
Bernard L. Weiss

1996 ◽  
Vol 99 (12) ◽  
pp. 897-900 ◽  
Author(s):  
Baoping Zhang ◽  
Takanari Yasui ◽  
Takashi Yasuda ◽  
Yusaburo Segawa ◽  
Hiroyuki Yaguchi ◽  
...  

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