Transient photoconductivity, density of tail states and doping effect in a-Si:H

Author

Merazga, A. ; Belgacem, H. ; Main, C. ; Reynolds, S.

Author_Institution

Inst. d´´Electron., Univ. Mohammed Khider, Biskra, Algeria

fYear

1999

fDate

22-24 Nov. 1999

Firstpage

267

Lastpage

270

Abstract

The transient photoconductivity (TPC) is studied in the pre-recombination time range on the basis of a multiple trapping (MT) model which uses a transient occupation function to account for simultaneous interactions of all the tail states with the conduction band. A direct inversion method for the extraction of the density of states (DOS) from the TPC data in amorphous semiconductors is derived. Application of this transient spectroscopy to n-type a-Si:H results in a very narrow band tail (0.014 eV width) around 0.16 eV below the mobility edge, leading to low DOS. This finding is in favour of the defect pool concept, and involves some doping effects at the donor level.

Keywords

amorphous semiconductors; carrier mobility; conduction bands; electron traps; electronic density of states; elemental semiconductors; hole traps; hydrogen; photoconductivity; semiconductor doping; silicon; Si:H; TPC data; a-Si:H; amorphous semiconductors; defect pool concept; density of states; density of tail states; direct inversion method; donor level doping effects; doping effect; mobility edge; multiple trapping model; n-type a-Si:H; narrow band tail; pre-recombination time range; simultaneous tail state-conduction band interactions; transient occupation function; transient photoconductivity; transient spectroscopy; Amorphous materials; Amorphous semiconductors; Charge carrier density; Data mining; Doping; Fourier transforms; Photoconductivity; Semiconductor process modeling; Spectroscopy; Tail;

fLanguage

English

Publisher

ieee

Conference_Titel

Microelectronics, 1999. ICM '99. The Eleventh International Conference on

Print_ISBN

0-7803-6643-3

Type

conf

DOI

10.1109/ICM.2000.884855

Filename

884855