Microstructure and Optoelectronic Properties of CdSe-Thin Films

1997 ◽  
Vol 472 ◽  
Author(s):  
U. Klement ◽  
F. Ernst
Keyword(s):  
Thin Films ◽  
Depth Profiling ◽  
Sample Surface ◽  
Substrate Material ◽  
Hydrogenated Silicon ◽  
Potential Barriers ◽  
Amorphous Hydrogenated Silicon ◽  
Thin Film Technique ◽  
Intergrain Boundaries ◽  
Electronic Eye

ABSTRACTCdSe appears to be a promising material to replace amorphous hydrogenated silicon as the photosensitive part in the retina of the “Electronic Eye”, a camera based on thin film technique. We have investigated the influence of post-depositional annealing treatments with respect to the optimization of the photoconductive properties. TEM-, AFM- and XPS-measurements on CdSe thin films are reported. The formation of an oxide could not be detected by XPS-depth profiling of films annealed in air but chemisorption of oxygen is expected at the intergrain boundaries. Hence, high potential barriers for electron transport will be introduced. Under illumination, trapping of photo-generated holes will neutralize the charge at the intergrain boundaries leading to improved electric properties. However, the homogeneity of the photoconductive properties in CdSe is not yet satisfying. The formation of swellings and holes on the sample surface, found by AFM-measurements, can perhaps explain the inhomogeneity of the photoconductive properties. Using Si wafers as substrate material no improvement in texturing could be reached, since an amorphous CdSe-interlayer is formed.

Microstructure of Thin Film Photoconductors and its Correlation with Optical and Electronic Properthss

1996 ◽  
Vol 452 ◽  
Author(s):  
U. Klement ◽  
D. Horst ◽  
F. Ernst
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hydrogenated Silicon ◽  
Amorphous Hydrogenated Silicon ◽  
Transmission Electron ◽  
Electronic Eye

AbstractThe objective of this work is to find a material to replace amorphous hydrogenated silicon used as photosensitive part in the “retina” of an “electronic eye”. For that reason, ZnS, ZnSe, CdS and CdSe were chosen for investigations. Thin films, prepared by chemical vapour deposition, were characterized by transmission electron microscopy. The observed microstructures were correlated with the optoelectronic properties of these materials. CdSe was found to be the most promising material for our application. Hence, the influence of a dielectric interlayer and the effects of additional annealing treatments were analyzed for CdSe and will be discussed with respect to the optimization of the material.

DEPOSITION-AND-SUBSTRATE TUNABLE PHOTONIC BANDGAP IN OPTICAL RESPONSES OF HYDROGENATED AMORPHOUS SILICON CARBIDE THIN FILMS

2003 ◽  
Vol 17 (09) ◽  
pp. 387-392 ◽  
Author(s):  
NIKIFOR RAKOV ◽  
ARSHAD MAHMOOD ◽  
MUFEI XIAO
Keyword(s):  
Thin Films ◽  
Silicon Carbide ◽  
Photonic Bandgap ◽  
Visible Spectrum ◽  
Incoherent Light ◽  
Hydrogenated Silicon ◽  
Optical Responses ◽  
Amorphous Hydrogenated Silicon ◽  
The Status ◽  
Two Parameters

Amorphous hydrogenated silicon carbide (a-SiC:H) thin films have been prepared by the RF reactive magnetron sputtering technique. The optical properties of the films have been studied by optical spectroscopy with an incoherent light source. The material is commonly regarded as a dielectric. We have discovered however that some films that were prepared under certain deposition conditions and on certain substrates may respond to external light as a metallic thin film, i.e. there are strongly enhanced reflection peaks in the optical spectrum. We have further discovered that some films may have a strong and broadened absorption peak at about 590 nm, which is an apparent photonic bandgap in the visible spectrum. The appearance of the photonic bandgap is very sensitive to two parameters: the substrate and the deposition gas. By changing the two parameters, one shifts the status of the film from with and without the photonic bandgap.

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

ChemInform Abstract: UHV Study of Hydrogen Atom Induced Etching of Amorphous Hydrogenated Silicon Thin Films.

ChemInform ◽  
2010 ◽  
Vol 32 (39) ◽  
pp. no-no
Author(s):  
Thomas Zecho ◽  
Birgit D. Brandner ◽  
Juergen Biener ◽  
Juergen Kueppers
Keyword(s):  
Thin Films ◽  
Hydrogen Atom ◽  
Hydrogenated Silicon ◽  
Silicon Thin Films ◽  
Amorphous Hydrogenated Silicon

Carbon Local Bonding Configurations in Amorphous Hydrogenated Silicon-Carbon Alloys

1987 ◽  
Vol 95 ◽  
Author(s):  
Mark A. Petrich ◽  
Jeffrey A. Reimer
Keyword(s):  
Thin Films ◽  
Nuclear Magnetic Resonance ◽  
Silicon Carbide ◽  
Magnetic Resonance ◽  
Hydrogenated Silicon ◽  
Nmr Data ◽  
Amorphous Hydrogenated Silicon ◽  
Nmr Study ◽  
Silicon Carbon ◽  
Local Bonding

AbstractWe present the results of a carbon-13 nuclear magnetic resonance (NMR) study of well-characterized thin films of amorphous hydrogenated silicon carbide. The NMR data detail the distribution of carbon local bonding configurations in films which have carbon-to-silicon ratios less than one. In particular, we show data which clearly identify and quantify non-hydrogenated sp2, or unsaturated, carbon bonding environments.

Studies on the thickness-dependent photofield effect in amorphous hydrogenated silicon thin films

1991 ◽  
Vol 198 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
V. Jayan ◽  
L.P. Lailamoni ◽  
K.J. Thomas ◽  
J. Majhi ◽  
P.R. Vaya
Keyword(s):  
Thin Films ◽  
Hydrogenated Silicon ◽  
Silicon Thin Films ◽  
Amorphous Hydrogenated Silicon

Optically Induced Paramagnetism in Amorphous Hydrogenated Silicon Nitride Thin Films

1992 ◽  
Vol 242 ◽  
Author(s):  
W. L. Warren ◽  
J. Kanicki ◽  
F. C. Rong ◽  
W. R. Buchwald ◽  
M. Harmatz
Keyword(s):  
Thin Films ◽  
Silicon Nitride ◽  
Ultra Violet ◽  
Dangling Bond ◽  
Hydrogenated Silicon ◽  
Uv Illumination ◽  
Defect Centers ◽  
Amorphous Hydrogenated Silicon ◽  
The Creation ◽  
A Charge

ABSTRACTThe creation mechanisms of Si and N dangling bond defect centers in amorphous hydrogenated silicon nitride thin films by ultra-violet (UV) illumination are investigated. The creation efficiency and density of Si centers in the N-rich films are independent of illumination temperature, strongly suggesting that the creation mechanism of the spins is electronic in nature, i.e., a charge transfer mechanism. However, our results suggest that the creation of the Si dangling bond in the Si-rich films are different. Last, we find that the creation of the N dangling-bond in N-rich films can be fit to a stretched exponential time dependence, which is characteristic of dispersive charge transport.

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