The Urbach tail in amorphous semiconductors

1977 ◽  
Vol 10 (9) ◽  
pp. L263-L266 ◽  
Author(s):  
I Z Kostadinov
2001 ◽  
Vol 664 ◽  
Author(s):  
Valeri Ligatchev

ABSTRACTIt is usually assumed that optical and electrical properties of amorphous semiconductors are determined by the short-range-order (SRO) parameters of atomic structure. The SRO parameters behavior is considered here as governed by morphology geometrical parameters (MGP) variations. Generalized Skettrup model is developed for a quantitative description of the MGP influence on the density of electron states distribution N(E). Common N(E) relation for the power, exponential and the ‘defect’ regions of the dependence is derived both for adiabatic (optical) and non-adiabatic (thermal) electron excitation processes. The simulated (by the N(E) convolution) spectral dependence of the opti-cal absorption coefficient contains the Tauc, Urbach and the ‘defect’ parts. The optical gap and the Urbach tail slope energies are typical for the ‘device quality’ a-Si:H films at the average morphology geometrical parameters values of order of 1 μm. Nearly linear the optical gap versus the Urbach tail slope energies dependence is obtained at the mor-phology geometrical parameters and temperature changes. Good agreement of experi-mental and the simulation results is achieved for a-Si:H films, prepared both by the RF sputtering and by the silane decomposition.


1972 ◽  
Vol 33 (C3) ◽  
pp. C3-157-C3-165 ◽  
Author(s):  
B. KRAMER ◽  
K. MASCHKE ◽  
P. THOMAS

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-395-C4-398 ◽  
Author(s):  
M. Wautelet ◽  
R. Andrew ◽  
M. Failly-Lovato ◽  
L. D. Laude

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-855-C4-864 ◽  
Author(s):  
E. A. Davis

1994 ◽  
Vol 75 (11) ◽  
pp. 7349-7355 ◽  
Author(s):  
D. S. Shen ◽  
J. P. Conde ◽  
V. Chu ◽  
S. Wagner

1998 ◽  
Vol 540 ◽  
Author(s):  
J. M. Gibson ◽  
J-Y. Cheng ◽  
P. Voyles ◽  
M.M.J. TREACY ◽  
D.C. Jacobson

AbstractUsing fluctuation microscopy, we show that ion-implanted amorphous silicon has more medium-range order than is expected from the continuous random network model. From our previous work on evaporated and sputtered amorphous silicon, we conclude that the structure is paracrystalline, i.e. it possesses crystalline-like order which decays with distance from any point. The observation might pose an explanation for the large heat of relaxation that is evolved by ion-implanted amorphous semiconductors.


1980 ◽  
Vol 35-36 ◽  
pp. 55-60 ◽  
Author(s):  
Morrel H. Cohen ◽  
J. Singh ◽  
F. Yonezawa

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