Optical Absorption in Co-Deposited Mixed-Phase Hydrogenated Amorphous/Nanocrystalline Silicon Thin Films

2010 ◽  
Vol 1245 ◽  
Author(s):  
Lee Wienkes ◽  
Aaron Besaw ◽  
Curtis Anderson ◽  
David Bobela ◽  
Paul Stradins ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Defect Density ◽  
Amorphous Material ◽  
Nanocrystalline Silicon ◽  
Esr Spectra ◽  
Hydrogenated Silicon ◽  
Silicon Thin Films ◽  
Electron Donation

AbstractThe conductivity of amorphous/nanocrystalline hydrogenated silicon thin films (a/nc-Si:H) deposited in a dual chamber co-deposition system exhibits a non-monotonic dependence on the nanocrystal concentration. Optical absorption measurements derived from the constant photocurrent method (CPM) and preliminary electron spin resonance (ESR) data for similarly prepared materials are reported. The optical absorption spectra, in particular the subgap absorption, are found to be independent of nanocrystalline density for relatively small crystal fractions (< 4%). For films with a higher crystalline content, the absorption spectra indicate broader Urbach slopes and higher midgap absorption. The ESR spectra show an approximately constant defect density across all of the films. These data are interpreted in terms of a model involving electron donation from the nanocrystals into the amorphous material.

A study of optical absorption in amorphous hydrogenated silicon thin films of varied thickness

2010 ◽  
Vol 256 (18) ◽  
pp. 5667-5671 ◽  
Author(s):  
J. Müllerová ◽  
L. Prušáková ◽  
M. Netrvalová ◽  
V. Vavruňková ◽  
P. Šutta
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Hydrogenated Silicon ◽  
Silicon Thin Films ◽  
Amorphous Hydrogenated Silicon

Magnetic Resonance in Hydrogenated Nanocrystalline Silicon Thin Films

2008 ◽  
Vol 1066 ◽  
Author(s):  
Tining Su ◽  
Tong Ju ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Subhendu Guha ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Spin Resonance ◽  
Magnetic Resonance ◽  
Optical Absorption ◽  
Electronic States ◽  
Amorphous Region ◽  
Nanocrystalline Silicon ◽  
Silicon Thin Films ◽  
Exciting Photon ◽  
Spin Resonance

ABSTRACTWe have investigated the localized electronic states in mixed-phase hydrogenated nanocrystalline silicon thin films (nc-Si:H) with electron-spin-resonance (ESR). The dark ESR signal most likely arises from defects at the grain boundaries or within the crystallites. With illumination with photon energies ranging from 1.2 eV to 2.0 eV, there is no evidence of photo-induced carriers trapped in the bandtail states within the amorphous region. Dependence of the light-induced ESR (LESR) upon the exciting photon energy reveals that, at different excitation photon energies, different regions dominate the optical absorption. This behavior may have potential consequences for understanding the light-induced degradation in nc-Si:H.

Monte Carlo Simulation of the Optical Absorption of Hydrogenated Nanocrystalline Silicon Thin Films

2008 ◽  
Author(s):  
Fatiha Besahraoui ◽  
Jamal Dine Sib ◽  
Yahia Bouizem ◽  
Larbi Chahed ◽  
B. G. Sidharth ◽  
...  
Keyword(s):  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Optical Absorption ◽  
Nanocrystalline Silicon ◽  
Silicon Thin Films

Giant Anisotropy of Conductivity in Hydrogenated Nanocrystalline Silicon Thin Films

1998 ◽  
Vol 536 ◽  
Author(s):  
A. B. Pevtsov ◽  
N. A. Feoktistov ◽  
V. G. Golubev
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Percolation Theory ◽  
Nanocrystalline Silicon ◽  
Spatial Light Modulators ◽  
Light Emitting ◽  
Light Modulators ◽  
Silicon Thin Films ◽  
Longitudinal Conductivity ◽  
Transverse Conductivity

AbstractThin (<1000 Å) hydrogenated nanocrystalline silicon films are widely used in solar cells, light emitting diodes, and spatial light modulators. In this work the conductivity of doped and undoped amorphous-nanocrystalline silicon thin films is studied as a function of film thickness: a giant anisotropy of conductivity is established. The longitudinal conductivity decreases dramatically (by a factor of 109 − 1010) as the layer thickness is reduced from 1500 Å to 200 Å, while the transverse conductivity remains close to that of a doped a- Si:H. The data obtained are interpreted in terms of the percolation theory.

scholarly journals Influence of deposition parameters on the optical absorption of amorphous silicon thin films

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Lukas Terkowski ◽  
Iain W. Martin ◽  
Daniel Axmann ◽  
Malte Behrendsen ◽  
Felix Pein ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Amorphous Silicon ◽  
Silicon Thin Films ◽  
Deposition Parameters

INVESTIGATION OF THE Si:H FILMS DEPOSITED NEAR THE TRANSITION REGION FOR APPLICATION IN SOLAR CELLS

2006 ◽  
Vol 20 (27) ◽  
pp. 1739-1747 ◽  
Author(s):  
QINGSONG LEI ◽  
ZHIMENG WU ◽  
XINHUA GENG ◽  
YING ZHAO ◽  
JIANPING XI
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Transition Region ◽  
Chemical Vapor ◽  
Transition Process ◽  
Very High Frequency ◽  
Working Pressure ◽  
Hydrogenated Silicon ◽  
Silicon Thin Films ◽  
Narrow Region

Hydrogenated silicon thin films (Si:H) have been deposited by using very high-frequency plasma-enhanced chemical vapor deposition (VHF PECVD). The structural, electrical and optical properties of the films were characterized. The transition process and the effect of pressure were studied. Results suggest that a narrow region, in which the transition from microcrystalline to amorphous growth takes place, exists in the regime of silane concentration (SC). This region is influenced by the working pressure (P). At lower pressure, the transition region is shifted to higher SC. Microcrystalline silicon (μ c-Si:H ) thin films deposited near transition region was applied as i-layer to the p-i-n solar cells. An efficiency of about 5.30% was obtained.

Internal structure of mixed phase hydrogenated silicon thin films made at 39°C

2006 ◽  
Vol 89 (5) ◽  
pp. 051922 ◽  
Author(s):  
P. C. P. Bronsveld ◽  
J. K. Rath ◽  
R. E. I. Schropp ◽  
T. Mates ◽  
A. Fejfar ◽  
...  
Keyword(s):  
Thin Films ◽  
Internal Structure ◽  
Mixed Phase ◽  
Hydrogenated Silicon ◽  
Silicon Thin Films

Quantitative photopyroelectric out-of-phase spectroscopy of amorphous silicon thin films deposited on crystalline silicon

1991 ◽  
Vol 69 (3-4) ◽  
pp. 317-323 ◽  
Author(s):  
Constantinos Christofides ◽  
Andreas Mandelis ◽  
Albert Engel ◽  
Michel Bisson ◽  
Gord Harling
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Absorption Coefficient ◽  
Dynamic Range ◽  
Crystalline Silicon ◽  
Optical Absorption Coefficient ◽  
Si Substrates ◽  
Silicon Thin Films ◽  
Background Compensation

A photopyroelectric spectrometer with real-time and(or) self-normalization capability was used for both conventional transmission and thermal-wave spectroscopic measurements of amorphous Si thin films, deposited on crystalline Si substrates. Optical-absorption-coefficient spectra were obtained from these measurements and the superior dynamic range of the out-of-phase (quadrature) photopyroelectric signal was established as the preferred measurement method, owing to its zero-background compensation capability. An extension of a photopyroelectric theoretical model was established and successfully tested in the determination of the optical absorption coefficient and the thermal diffusivity of the sample under investigation. Instrumental sensitivity limits of βt ≈ 5 × 10−3 were demonstrated.

Sign in / Sign up

Export Citation Format

Share Document