Light Induced Modulation of Absorption (LIMA) of CdS Crystals

1969 ◽  
Vol 24 (9) ◽  
pp. 1306-1310 ◽  
Author(s):  
K.W. Böer

Abstract With chopped high intensity optical excitation a modulation of the optical absorption in a wide wavelength-range in CdS was observed. This light induced modulation of absorption is attributed to a redistribution of carriers over levels in the band gap following the chopping frequency. With this method the energy spectrum of certain traps and recombination centers can be determined and their frequency factor and capture cross section obtained. This method permits also the analysis of fast recombination centers.

1991 ◽  
Vol 219 ◽  
Author(s):  
B.-G. Yoon ◽  
H. Fritzsche ◽  
M. Q. Tran ◽  
D.-Z. Chi

ABSTRACTThermal quenching (TQ) of photoconductivity σp occurs when the demarkation level of minority carriers passes through recombination centers having small capture cross section for majority carriers compared to other centers present but normal cross section for minority carriers. The photoconductivity becomes superlinear with light intensity at the temperature of maximum TQ. We discovered TQ not only in n-type but also p-type a-Si:H. This cannot happen with the same centers unless the sign of the majority carriers changes. We present evidence that in p-type and undoped films majority carriers are electrons at T below TQ and holes above TQ. The nature of these special centers will be discussed.


Author(s):  
Yu Kodama ◽  
Tatsuya Katabuchi ◽  
Gerard Rovira ◽  
Atsushi Kimura ◽  
Shoji Nakamura ◽  
...  

1953 ◽  
Vol 31 (3) ◽  
pp. 204-206 ◽  
Author(s):  
Rosalie M. Bartholomew ◽  
R. C. Hawkings ◽  
W. F. Merritt ◽  
L. Yaffe

The thermal neutron capture cross sections of Na23 and Mn55 have been determined using the activation method. The values are 0.53 ± 0.03 and 12.7 ± 0.3 barns respectively with respect to σAul97 = 93 barns. These agree well with recent pile oscillator results. The half-life for Mn56 is found to be 2.576 ± 0.002 hr.


2017 ◽  
Vol 146 ◽  
pp. 11054
Author(s):  
M. Mastromarco ◽  
M. Barbagallo ◽  
M.J. Vermeulen ◽  
N. Colonna ◽  
S. Altstadt ◽  
...  

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