Optoelectronic Properties of Amorphous SiGec Alloys

ABSTRACTWe describe the optoelectronic characteristics of hydrogenated amorphous silicon germanium carbon (a.Si1-x-yGexCy:H) alloys prepared by plasma deposition from SiH4/GeH4/CH4/H2 gas mixtures. a-Si1-x-yGexCy:H is a homogeneous random alloy having a variable optical gap depending on composition, with properties similar to those of amorphous Si-Ge alloys of the same optical gap but with improved thermal stability. Calculations show that if the ratio of Ge/C atomic fractions is 8.2, the average bond length matches that of unalloyed amorphous a-Si:H with the possibility of reduced defect densities at heterointerfaces. After light-soaking with high intensity white light, a sample having a 1.3 eV optical gap exhibited no Staebler-Wronski change in its properties.

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In-situ monitoring and control of hydrogenated amorphous silicon–germanium band-gap profiling during plasma deposition process

Current Applied Physics ◽

10.1016/j.cap.2013.05.005 ◽

2013 ◽

Vol 13 (7) ◽

pp. 1502-1505 ◽

Cited By ~ 5

Author(s):

Se Youn Moon ◽

D.J. You ◽

S.E. Lee ◽

Heonmin Lee

Keyword(s):

Silicon Germanium ◽

Plasma Deposition ◽

Hydrogenated Amorphous Silicon ◽

Deposition Process ◽

In Situ Monitoring ◽

Monitoring And Control ◽

And Control ◽

Amorphous Silicon Germanium ◽

Hydrogenated Amorphous

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Properties of Catalytic-Cvd Amorphous Silicon-Germanium (a-SiGe:H)

MRS Proceedings ◽

10.1557/proc-192-499 ◽

1990 ◽

Vol 192 ◽

Cited By ~ 1

Author(s):

Hideki Matsumura ◽

Masaaki Yamaguchi ◽

Kazuo Morigaki

Keyword(s):

Amorphous Silicon ◽

Silicon Germanium ◽

Hydrogenated Amorphous Silicon ◽

Chemical Vapor ◽

Characteristic Energy ◽

Optical Band Gaps ◽

Spin Resonance ◽

Amorphous Silicon Germanium ◽

Conductive Properties ◽

Hydrogenated Amorphous

ABSTRACTHydrogenated amorphous silicon-germanium (a-SiGe:H) films are prepared by the catalytic chemical vapor deposition (Cat-CVD) method using a SiH4, GeH4 and H4 gas mixture. Properties of the films are investigated by the photo-thermal deflection spectroscopy (PDS) and electron spin resonance (ESR) measurements, in addition to the photo-conductive and structural studies. It is found that the characteristic energy of Urbach tail, ESR spin density and other photo-conductive properties of Cat-CVD a-SiGe:H films with optical band gaps around 1.45 eV are almost equivalent to those of the device quality glow discharge hydrogenated amorphous silicon (a-Si:H).

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Development of Stable a-Si/a-SiGe Tandem Solar Cell Submodules Deposited by a Very High Hydrogen Dilution at Low Temperature

MRS Proceedings ◽

10.1557/proc-507-145 ◽

1998 ◽

Vol 507 ◽

Cited By ~ 8

Author(s):

Masaki Shima ◽

Masao Isomura ◽

Eiji Maruyama ◽

Shingo Okamoto ◽

Hisao Haku ◽

...

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Silicon Germanium ◽

Structural Variations ◽

High Hydrogen ◽

Hydrogen Dilution ◽

Hydrogen Radicals ◽

Amorphous Silicon Germanium ◽

Hydrogenated Amorphous ◽

Very High

ABSTRACTThe world's highest stabilized efficiency of 9.5% (light-soaked and measured by the Japan Quality Assurance Organization (JQA)) for an a-Si/a-SiGe superstrate-type solar cell submodule (area: 1200 cm2) has been achieved. This value was obtained by investigating the effects of very-high hydrogen dilution of up to 54:1 (= H2: SiH4) on hydrogenated amorphous silicon germanium (a-SiGe:H) deposition at a low substrate temperature (Ts). It was found that deterioration of the film properties of a-SiGe:H when Ts decreases under low hydrogen dilution conditions can be suppressed by the high hydrogen dilution. This finding probably indicates that the energy provided by hydrogen radicals substitutes for the lost energy caused by the decrease in Ts and that sufficient surface reactions can occur. In addition, results from an estimation of the hydrogen and germanium contents of a-SiGe:H suggest the occurrence of some kinds of structural variations by the high hydrogen dilution. A guideline for optimization of a-SiGe:H films for solar cells can be presented on the basis of the experimental results. The possibility of a-SiGe:H as a narrow gap material for a-Si stacked solar cells in contrast with microcrystalline silicon (μ c-Si:H) will also be discussed from various standpoints. At present, a-SiGe:H is considered to have an advantage over μ1 c-Si:H.

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