Optical Absorption in Amorphous Silicon

1996 ◽  
Vol 420 ◽  
Author(s):  
S. K. O'Leary ◽  
S. Zukotynski ◽  
J. M. Perz ◽  
L. S. Sidhu

AbstractThe role that disorder plays in shaping the form of the optical absorption spectrum of hydrogenated amorphous silicon is investigated. Disorder leads to a redistribution of states, which both reduces the ‘Tauc’ gap and broadens the absorption tail. The observed relationship between the ‘Tauc’ gap and the breadth of the absorption tail is thus explained.

1991 ◽  
Vol 219 ◽  
Author(s):  
J. Fan ◽  
J. Kakalios

ABSTRACTMeasurements of the optical absorption spectrum of doped and undoped hydrogenated amorphous silicon (a-Si:H) for photon energies ranging from 0.8 to 2.5 eV are obtained using photo-pyroelectric spectroscopy (PPES). This technique, based upon the pyroelectric effect, has a simpler experimental set-up than photo-thermal deflection spectroscopy, and presently has a sensitivity of ad > 10-3, where d is the sample thickness. In addition, using PPES we have measured the non-radiative quantum efficiency in a-Si:H, and find that it has a strong wavelength dependence for sub-bandgap illumination.


1999 ◽  
Vol 557 ◽  
Author(s):  
D. E. Sweenor ◽  
S. K. O'Leary ◽  
B. E. Foutz

AbstractThere are many different empirical means whereby the optical gap of an amorphous semiconductor may be defined. We analyze some hydrogenated amorphous silicon data with respect to a number of these empirical measures for the optical gap. By plotting these various gap measures as a function of the breadth of the optical absorption tail, we provide a means of relating these disparate measures of the optical gap. The applicability of this calibration to another set of hydrogenated amorphous silicon data is investigated.


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