Laplace-transform transient photocurrent spectroscopy as a probe of metastable defect distributions in hydrogenated amorphous silicon

Mariana J. Gueorguieva, Charlie Main, Steve Reynolds

Research output: Contribution to journalConference article

6 Citations (Scopus)

Abstract

Three Laplace transform methods for recovering the density of electronic states from transient photocurrent data are evaluated through a study of light-induced defect creation in PECVD a-Si:H films. A mathematically approximate method is shown to be sufficient to resolve the deep defects, whose density is estimated to increase by a factor of five from the annealed state after 3 hours' exposure to simulated AM1 illumination. An exact method, and a method employing Tikhonov regularisation, are found to give very similar results, provided the current-time data are smoothed beforehand in the former case. The increased resolution available is, however, unnecessary here, and these methods are shown to be more suited to the study of discrete levels or narrow distributions.

Original languageEnglish
Article numberA19.3
JournalMaterials Research Society Symposium - Proceedings
Volume664
DOIs
Publication statusPublished - 2001
EventAmorphous and Heterogeneous Silicon Based Films 2001 - San Francisco, CA, United States
Duration: 16 Apr 200120 Apr 2001

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Electronic density of states
Defect density
Laplace transforms
Plasma enhanced chemical vapor deposition
Amorphous silicon
Photocurrents
amorphous silicon
photocurrents
Lighting
Spectroscopy
Defects
probes
defects
spectroscopy
illumination
electronics

Cite this

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title = "Laplace-transform transient photocurrent spectroscopy as a probe of metastable defect distributions in hydrogenated amorphous silicon",
abstract = "Three Laplace transform methods for recovering the density of electronic states from transient photocurrent data are evaluated through a study of light-induced defect creation in PECVD a-Si:H films. A mathematically approximate method is shown to be sufficient to resolve the deep defects, whose density is estimated to increase by a factor of five from the annealed state after 3 hours' exposure to simulated AM1 illumination. An exact method, and a method employing Tikhonov regularisation, are found to give very similar results, provided the current-time data are smoothed beforehand in the former case. The increased resolution available is, however, unnecessary here, and these methods are shown to be more suited to the study of discrete levels or narrow distributions.",
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Laplace-transform transient photocurrent spectroscopy as a probe of metastable defect distributions in hydrogenated amorphous silicon. / Gueorguieva, Mariana J.; Main, Charlie; Reynolds, Steve.

In: Materials Research Society Symposium - Proceedings, Vol. 664, A19.3, 2001.

Research output: Contribution to journalConference article

TY - JOUR

T1 - Laplace-transform transient photocurrent spectroscopy as a probe of metastable defect distributions in hydrogenated amorphous silicon

AU - Gueorguieva, Mariana J.

AU - Main, Charlie

AU - Reynolds, Steve

PY - 2001

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N2 - Three Laplace transform methods for recovering the density of electronic states from transient photocurrent data are evaluated through a study of light-induced defect creation in PECVD a-Si:H films. A mathematically approximate method is shown to be sufficient to resolve the deep defects, whose density is estimated to increase by a factor of five from the annealed state after 3 hours' exposure to simulated AM1 illumination. An exact method, and a method employing Tikhonov regularisation, are found to give very similar results, provided the current-time data are smoothed beforehand in the former case. The increased resolution available is, however, unnecessary here, and these methods are shown to be more suited to the study of discrete levels or narrow distributions.

AB - Three Laplace transform methods for recovering the density of electronic states from transient photocurrent data are evaluated through a study of light-induced defect creation in PECVD a-Si:H films. A mathematically approximate method is shown to be sufficient to resolve the deep defects, whose density is estimated to increase by a factor of five from the annealed state after 3 hours' exposure to simulated AM1 illumination. An exact method, and a method employing Tikhonov regularisation, are found to give very similar results, provided the current-time data are smoothed beforehand in the former case. The increased resolution available is, however, unnecessary here, and these methods are shown to be more suited to the study of discrete levels or narrow distributions.

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M3 - Conference article

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JO - Materials Research Society Symposium Proceedings

JF - Materials Research Society Symposium Proceedings

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