Evaluation Of The Gap State Distribution In a-Si:H By SCLC Measurements

2002 ◽  
pp. 253-256
Author(s):  
A. Eray ◽  
G. Nobile
Keyword(s):  
State Distribution ◽  
Gap State

Photoelectron spectroscopic investigations of very thin a-Si:H layers

2003 ◽  
Vol 762 ◽  
Author(s):  
M. Schmidt ◽  
A. Schoepke ◽  
O. Milch ◽  
Th. Lussky ◽  
W. Fuhs
Keyword(s):  
Fermi Level ◽  
Gas Phase ◽  
Photoelectron Spectroscopy ◽  
Doping Level ◽  
Urbach Energy ◽  
Deposition Process ◽  
State Density ◽  
State Distribution ◽  
20 Nm ◽  
Gap State

AbstractWe report on a detailed study on gap-state distribution in thin amorphous silicon layers (a-Si:H) with film thicknesses between 5 nm and 20 nm on c-Si wafers performed by UV excited photoelectron spectroscopy (UV-PES). We measured how the work function, the gap state density, the position of the Fermi-level and the Urbach-energy depend on the layer thickness and the doping level of the ultra thin a-Si:H(n) layers. It was found, that for phosphorous doping the position of the Fermi level saturates at EF–EV=1.47 eV. This is achieved at a gas phase concentration of 10000 ppm PH3 in the SiH4/H2 mixture which was used for the PECVD deposition process. The variation of the doping level from 0 to 20000 ppm PH3 addition results in an increase of the Urbach energy from 65 meV to 101 meV and in an increase of the gap state density at midgap (EV-Ei= 0.86eV) from 3·1018 to 2·1019 cm-3eV-1.

Gap state distribution of amorphous hydrogenated Si and Si:Ge alloys

1983 ◽  
Vol 59-60 ◽  
pp. 545-548 ◽  
Author(s):  
C.-Y. Huang ◽  
S. Guha ◽  
S.J. Hudgens
Keyword(s):  
State Distribution ◽  
Gap State

Urbach tail and gap state distribution in as-deposited and annealed a-(C-Si-Ge): H alloys

1989 ◽  
Vol 60 (5) ◽  
pp. 713-720 ◽  
Author(s):  
F. Demichelis ◽  
G. Kaniadakis ◽  
R. Spagnolo ◽  
E. Tresso
Keyword(s):  
State Distribution ◽  
Urbach Tail ◽  
Gap State

Defect pool gap-state distribution in a-Si:H in equilibrium and under photoexcitation

1992 ◽  
Author(s):  
Gottfried H. Bauer ◽  
C.-D. Abel ◽  
G. Schumm
Keyword(s):  
State Distribution ◽  
Gap State

The Influence of Interfaces on the Gap State Distribution of Undoped a-Si:H

1990 ◽  
Vol 192 ◽  
Author(s):  
G. Schumm ◽  
G. H. Bauer
Keyword(s):  
Fermi Level ◽  
Transit Time ◽  
Reverse Bias ◽  
State Distribution ◽  
Band Bending ◽  
Time Regime ◽  
Level Shifts ◽  
Pool Model ◽  
Annealing Effects ◽  
Gap State

ABSTRACTModulated primary photocurrent (MPC) studies on pin structures show spatial variations of the gap state distribution across the i-layer that can be correlated with Fermi level shifts by band bending towards interfaces. These results as well as reverse bias annealing effects are explained in terms of the defect pool model. It is demonstrated that MPC measurements are basically identical to TOF measurements with clear advantages in the post-transit time regime.

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