High-Rate Growth of Stable a-Si:H

1999 ◽  
Vol 557 ◽  
Author(s):  
T. Takagi ◽  
R. Hayashi ◽  
A. Payne ◽  
W. Futako ◽  
T. Nishimoto ◽  
...  
Keyword(s):  
Vapour Deposition ◽  
Film Growth ◽  
Density Ratio ◽  
Excitation Frequency ◽  
Chemical Vapour ◽  
High Growth ◽  
High Growth Rate ◽  
High Rate ◽  
Hydrogenated Amorphous ◽  
Silane Plasma

AbstractCorrelation between the gas phase species in silane plasma measured by mass spectrometry and the properties of hydrogenated amorphous silicon (a-Si:H) films deposited by plasma enhanced chemical vapour deposition (PECVD) has been investigated. We have especially been interested in the higher-order silane related species in the plasma, whose contribution to the film growth is considered to be the cause of light-induced degradation in the film quality, especially at high growth rate. In this study, we varied excitation frequency, gas pressure and power density to vary the growth rates of a-Si:H films ranging from 2 Å/s to 20 Å/s.Molecular density ratio of trisilane, representative of higher silane related radicals, to monosilane has shown a clear correspondence to the fill factor after light soaking of Schottky cells fabricated on the resulting films.

Control of Materials and Interfaces in μc-Si:H-based Solar Cells Grown at High Rate

2011 ◽  
Vol 1321 ◽  
Author(s):  
Yasushi Sobajima ◽  
Chitose Sada ◽  
Akihisa Matsuda ◽  
Hiroaki Okamoto
Keyword(s):  
Growth Rate ◽  
Solar Cells ◽  
Film Growth ◽  
Defect Density ◽  
Density Measurement ◽  
High Growth ◽  
High Growth Rate ◽  
High Rate ◽  
Bulk Region ◽  
Dangling Bond

ABSTRACTGrowth process of microcrystalline silicon (μc-Si:H) using plasma-enhanced chemicalvapor- deposition method under high-rate-growth condition has been studied for the control of optoelectronic properties in the resulting materials. We have found two important things for the spatial-defect distribution in the resulting μc-Si:H through a precise dangling-bond-density measurement, e. g., (1) dangling-bond defects are uniformly distributed in the bulk region of μc- Si:H films independent of their crystallite size and (2) large number of dangling bonds are located at the surface of μc-Si:H especially when the film is deposited at high growth rate. Starting procedure of film growth has been investigated as an important process to control the dangling-bond-defect density in the bulk region of resulting μc-Si:H through the change in the electron temperature by the presence of particulates produced at the starting period of the plasma. Deposition of Si-compress thin layer on μc-Si:H grown at high rate followed by thermal annealing has been proposed as an effective method to reduce the defect density at the surface of resulting μc-Si:H. Utilizing the starting-procedure-controlling method and the compress-layerdeposition method together with several interface-controlling methods, we have demonstrated the fabrication of high conversion-efficiency (9.27%) substrate-type (n-i-p) μc-Si:H solar cells whose intrinsic μc-Si:H layer is deposited at high growth rate of 2.3 nm/sec.

Process Parameters for Poly-Silicon Deposition at a High Growth Rate (1-7 nm/s) by Hot-Wire Chemical Vapour Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
J.K. Rath ◽  
A.J. Hardeman ◽  
C.H.M. van der Werf ◽  
P.A.T.T. van Veenendaal ◽  
M.Y.S. Rusche ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chemical Vapour Deposition ◽  
Process Parameters ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
High Growth ◽  
High Growth Rate ◽  
Hot Wire ◽  
High Hydrogen ◽  
Si Films

AbstractHigh silane to hydrogen flow ratios and optimum wire temperatures are the key process parameters to achieve high growth rate poly-silicon films by hot wire chemical vapour deposition (HWCVD) using a four-wire hot-wire assembly. Four tungsten wires, 4 cm apart from each other, were used as catalytic filaments. Growth rates higher than 7 nm/s have been achieved at a substrate temperature of ∼510°C. The increase in deposition rate was accompanied by deterioration of two physical properties i.e., decrease in photoresponse and increase in oxygen incorporation in the film, which is attributed to high porosity in the material that is commonly observed in these high growth rate materials. The process conditions to incorporate a high hydrogen content into the material for passivation of defects and donor states have been identified as high hydrogen dilution and lower wire temperature. With these procedures, poly-Si films deposited at 1.3 nm/s showed a high ambipolar diffusion length of 132 nm. Incorporating such poly-Si films as the i-layer in an n-i-p solar cell on a stainless steel substrate, without back reflector, showed an efficiency of 4.4 % and a high open circuit voltage of 0.58 V, which is attributed to effective passivation of defects and dopants by incorporated hydrogen.

Attempts to p-Dope Ultrananocrystalline Diamond Films in a Hot Filament Reactor

2006 ◽  
Vol 956 ◽  
Author(s):  
Paul William May ◽  
Matthew Hannaway
Keyword(s):  
Vapour Deposition ◽  
Film Growth ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapour ◽  
Grain Sizes ◽  
Ultrananocrystalline Diamond ◽  
The Individual ◽  
P Type ◽  
Hot Filament

ABSTRACTUltrananocrystalline diamond (UNCD) films have been deposited using hot filament chemical vapour deposition using Ar/CH4/H2 gas mixtures plus additions of B2H6 in an attempt to make p-type semiconducting films. With increasing additions of B2H6 from 0 to 40,000 ppm with respect to C, the film growth rate was found to decrease substantially, whilst the individual grain sizes increased from nm to μm. With 40,000 ppm of B2H6, crystals of boric oxide were found on the substrate surface, which slowly hydrolysed to boric acid on exposure to air. These results are rationalised using a model for UNCD growth based on competition for surface radical sites between CH3 and C atoms.

Thin film growth of gadolinia by metal-organic chemical vapour deposition (MOCVD)

1996 ◽  
Vol 286 (1-2) ◽  
pp. 64-71 ◽  
Author(s):  
John McAleese ◽  
John C Plakatouras ◽  
Brian C.H Steele
Keyword(s):  
Thin Film ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Film Growth ◽  
Chemical Vapour ◽  
Thin Film Growth ◽  
Organic Chemical ◽  
Metal Organic
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