Comparative study of the optical absorption spectra of amorphous hydrogenated silicon derived from photothermal deflection spectroscopy and photoconductivity measurements

AbstractAbsorption measurements of as deposited and photodegraded intrinsic amorphous hydrogenated silicon films were made using photothermal deflection spectroscopy (PDS). The films were light-soaked in situ using HeNe laser light to simulate AM1 illumination. An increase in subbandgap absorption occurred predominantly near energies of 1.2eV. A simple model was developed in which a density of states function is hypothesized and the resulting optical absorption at subgap energies is calculated. The measured absorption could be well matched in all cases by assuming a single peak of defect states at or slightly below the Fermi level. Further, the observed changes in optical absorption due to degradation could be modeled by increasing the density of the single peak of defect states and moving the Fermi level towards the valence band.

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Optical absorption spectra of P-type Tin monoxide thin films around their indirect fundamental gaps determined using photothermal deflection spectroscopy

Thin Solid Films ◽

10.1016/j.tsf.2013.05.141 ◽

2014 ◽

Vol 555 ◽

pp. 148-152 ◽

Cited By ~ 10

Author(s):

Toshihiko Toyama ◽

Yuichi Seo ◽

Takafumi Konishi ◽

Hiroaki Okamoto ◽

Ryohei Morimoto ◽

...

Keyword(s):

Thin Films ◽

Optical Absorption ◽

Absorption Spectra ◽

Optical Absorption Spectra ◽

Photothermal Deflection Spectroscopy ◽

Photothermal Deflection ◽

P Type ◽

Tin Monoxide

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Optical Absorption Spectra Under DC Light Bias in Undoped a-Si:H

MRS Proceedings ◽

10.1557/proc-258-795 ◽

1992 ◽

Vol 258 ◽

Cited By ~ 2

Author(s):

J. Z. Liu ◽

J. P. Conde ◽

G. Lewen ◽

P. Roca i Cabarrocas

Keyword(s):

Simple Model ◽

Absorption Band ◽

Optical Absorption ◽

Absorption Spectra ◽

Optical Absorption Spectra ◽

Recombination Lifetime ◽

Photothermal Deflection Spectroscopy ◽

Photothermal Deflection

ABSTRACTUnder a dc light bias, the ac constant photocurrent method (CPM) yields an anomalous subgap optical absorption over that without the bias. When the intensity of the bias is high, an absorption band appears. However, absorption measured by ac photothermal deflection spectroscopy (PDS) is much less affected by the bias. A simple model qualitatively explains the effect on the PDS spectra and suggests that the anomalous CPM absorption is an apparent one which represents a variation of the recombination lifetime.

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Optical Absorption Spectra in Cobalt-Substituted Epitaxial Magnetic Garnet Films Measured with Photothermal Deflection Spectroscopy

Japanese Journal of Applied Physics ◽

10.1143/jjap.28.l656 ◽

1989 ◽

Vol 28 (Part 2, No. 4) ◽

pp. L656-L658 ◽

Cited By ~ 3

Author(s):

Kazumichi Yasuhiro ◽

Katsuaki Sato ◽

Ken Tamanoi ◽

Kiminari Shinagawa ◽

Toshiaki Saito ◽

...

Keyword(s):

Optical Absorption ◽

Absorption Spectra ◽

Optical Absorption Spectra ◽

Garnet Films ◽

Photothermal Deflection Spectroscopy ◽

Photothermal Deflection ◽

Magnetic Garnet

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A comparative study of EL2 and other deep centers in undoped SI GaAs using optical absorption spectra and photoconductivity measurements

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/s0168-9002(03)01871-0 ◽

2003 ◽

Vol 512 (1-2) ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

J.P. Kozlova ◽

T.J. Bowles ◽

V.K. Eremin ◽

V.N. Gavrin ◽

O.G. Koshelev ◽

...

Keyword(s):

Optical Absorption ◽

Comparative Study ◽

Absorption Spectra ◽

Optical Absorption Spectra ◽

Deep Centers

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Microstructure and Dangling Bond Defects in Amorphous Hydrogenated Silicon Deposited Near Room Temperature

MRS Proceedings ◽

10.1557/proc-258-191 ◽

1992 ◽

Vol 258 ◽

Cited By ~ 1

Author(s):

Man Ken Cheung ◽

Mark A. Petrich

Keyword(s):

Room Temperature ◽

Dangling Bond ◽

Optimum Conditions ◽

Band Tail ◽

Hydrogenated Silicon ◽

Photothermal Deflection Spectroscopy ◽

Amorphous Hydrogenated Silicon ◽

Photothermal Deflection ◽

Substrate Temperatures ◽

Absorption Measurements

ABSTRACTThe microstructure of high-density amorphous hydrogenated silicon (a-S.i:H) films deposited at 50°C substrate temperature was revealed by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies to be similar to that of “device-quality” a-Si:H films deposited at standard “optimum” conditions. However, optical absorption measurements of these low microstructure 50°C films with photothermal deflection spectroscopy indicate that they have higher densities of gap state defects and localized band tail states than “device-quality” films deposited at standard substrate temperatures. The correlation between the amount of microstructure and electronic properties is not unique. A low amount of microstructure is a necessary, but not sufficient, requirement for high electronic quality a-Si:H films.

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