Gap States in Hydrogenated Amorphous Silicon—Carbon Alloys

1985 ◽  
Vol 49 ◽  
Author(s):  
P. Fiorini ◽  
F. Evangelisti ◽  
A. Frova
Keyword(s):  
Amorphous Silicon ◽  
Recombination Rate ◽  
Transport Mechanism ◽  
Hydrogenated Amorphous Silicon ◽  
State Density ◽  
Defect State ◽  
Defect States ◽  
Silicon Carbon ◽  
Gap States ◽  
Hydrogenated Amorphous

AbstractTail and defect states in the gap of a-SixCl-x:H alloys have been studied by measurements of spectral photoconductivity. The variation of defect—state density versus x is found to be negligible. By comparison with PDS results the ητ product has been determined and found to be almost independent of photonenergy and to strongly decrease with inclusion of carbon. This effect is attributed to changes in the transport mechanism combined with an increased recombination rate associated with the widening of the gap.

Stability in Amorphous Silicon

1987 ◽  
Vol 95 ◽  
Author(s):  
Z E. Smith ◽  
S. Wagner
Keyword(s):  
Electron Spin Resonance ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Thermal Recovery ◽  
Defect States ◽  
Spin Resonance ◽  
Resonance Data ◽  
Electron Spin Resonance Data ◽  
Gap States ◽  
Hydrogenated Amorphous

AbstractThe experimental phenomena associated with light-induced degradation and thermal recovery of hydrogenated amorphous silicon (a-Si:H) films are reviewed, with special emphasis on the limitations of each experimental technique. When several techniques are used in concert, a fuller picture emerges. Recent experiments suggest different positions in the band-gap of the paramagnetic-associated defect states (the dangling bonds) for doped and undopedfilms; this information can be combined with conductivity, sub-bandgap optical absorption and electron spin resonance data to yield a model for the density of gap states (DOS) in a- Si:H, including how the DOS changes upon illumination and annealing.

EPR study of carbon and silicon related defects in carbon-rich hydrogenated amorphous silicon-carbon films

2010 ◽  
Vol 81 (15) ◽  
Author(s):  
E. N. Kalabukhova ◽  
S. N. Lukin ◽  
D. V. Savchenko ◽  
B. D. Shanina ◽  
A. V. Vasin ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Carbon Films ◽  
Silicon Carbon ◽  
Hydrogenated Amorphous

Theoretical Studies of Structure and Doping of Hydrogenated Amorphous Silicon

2011 ◽  
Vol 1321 ◽  
Author(s):  
Bin Cai ◽  
D. A. Drabold
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Theoretical Studies ◽  
Defect States ◽  
High Impurity ◽  
Bond Center ◽  
B Doping ◽  
Hydrogenated Amorphous ◽  
Center Site

ABSTRACTIn a-Si:H, large concentrations of B or P (of order 1%) are required to dope the material, suggesting that doping mechanisms are very different than for the crystal for which much smaller concentrations are required. In this paper, we report simulations on B and P introduced into realistic models of a-Si:H and a-Si, with concentrations ranging from 1.6% to 12.5% of B or P in the amorphous host. The results indicate that tetrahedral B and P are effective doping configurations in a-Si, but high impurity concentrations introduce many defect states. For a-Si:H, we report that both B(3,1) and P(3,1) (B or P atom bonded with three Si atoms and one H atom) are effective doping configurations. We investigate H passivation in both cases. For both B and P, there exists a “hydrogen poison range” of order 6 Å for which H in a bond-center site can suppress doping. For B doping, nearby H prefers to stay at the bond-center of Si-Si, leaves B four-fold and neutralizes the doping configuration; for P doping, nearby H spoils the doping by inducing a reconstruction rendering initially tetrahedral P three-fold.

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