Effect of Alloy Composition on the Optoelectronic Properties of Hydrogenated Microcrystalline Silicon-Germanium Films Deposited with Various Hydrogen Dilution

AbstractThe structural and optoelectronic properties of silicon thin films prepared by hot wire chemical vapor deposition and radio frequency plasma enhanced chemical vapor deposition are studied in the range of substrate temperatures (Tsub)from 100 °C to 25 °C. The defect density, structure factor and bond angle disorder of amorphous silicon films (a-Si:H) deposited by both techniques are strongly improved by the use of hydrogen dilution. Correlation of these structural properties with important optoelectronic properties, such as photo-to-dark conductivity ratio, is made. Microcrystalline silicon (μc-Si:H) is obtained using HW with a large crystalline fraction for hydrogen dilutions above 85% independently of Tsub. The deposition of μc-Si:H by RF requires increasing the hydrogen dilution and shows decreasing crystalline fraction as Tsub is decreased. The properties of the low Tsub films are compared to those of samples produced at 175 °C and 250 °C in the same reactors.

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Structural properties of microcrystalline silicon-germanium films

Philosophical Magazine Letters ◽

10.1080/095008399177561 ◽

1999 ◽

Vol 79 (2) ◽

pp. 71-78 ◽

Cited By ~ 4

Author(s):

L Houben

Keyword(s):

Structural Properties ◽

Silicon Germanium ◽

Microcrystalline Silicon ◽

Germanium Films

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Low Temperature Fabrication of Microcrystalline Silicon Germanium Films by RF Reactive Magnetron Sputtering

MRS Proceedings ◽

10.1557/proc-0910-a13-05 ◽

2006 ◽

Vol 910 ◽

Cited By ~ 1

Author(s):

Isao Nakamura ◽

Toru Ajiki ◽

Masao Isomura

Keyword(s):

Magnetron Sputtering ◽

Silicon Germanium ◽

Energy Gap ◽

Wavelength Region ◽

Reactive Magnetron Sputtering ◽

Reactive Magnetron ◽

Microcrystalline Silicon ◽

Long Wavelength ◽

Glass Substrates ◽

Germanium Films

AbstractMicrocrystalline silicon germanium films (μc-SiGe) were fabricated on Corning #7059 glass substrates by the RF reactive magnetron sputtering method. The μc-SiGe films with Ge fraction of 0.7-0.8 could be crystallized at of 200 °C by H2 introduction into the sputtering gases. The absorption coefficients of the films decrease in long wavelength region corresponding to the photon energies below the energy gap by the decrease in the substrate temperature and become close to those of single crystal Si0.25Ge0.75. The dark conductivities show lower values of 10-7 S/cm at 200 °C and 300 °C with H2 introduction. Besides, the photosensitivities are observed in these samples. These results indicate that the H2 introduction into the sputtering gas has two important effects to decrease the crystallization temperature of the μc-SiGe and to improve the film properties by reducing the dangling bond defects.

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Near Infrared Detectors and Solar Cells Based on Microcrystalline Silicon Germanium

MRS Proceedings ◽

10.1557/proc-609-a13.7 ◽

2000 ◽

Vol 609 ◽

Cited By ~ 2

Author(s):

M. Krause ◽

H. Stiebig ◽

R. Carius ◽

H. Wagner

Keyword(s):

Gas Phase ◽

Silicon Germanium ◽

Infrared Detectors ◽

Near Infrared ◽

Infrared Region ◽

Microcrystalline Silicon ◽

Germanium Content ◽

Cell Parameters ◽

Hydrogen Dilution ◽

Near Infrared Region

ABSTRACTMicrocrystalline silicon germanium alloys (ν-Si1−xGex:H) exhibit an enhanced optical absorption in the near infrared region with increasing germanium content. Therefore, the employment of this material as intrinsic absorber is a promising challenge for thin film technology in photovoltaics and sensorics. The influence of hydrogen dilution on the material and the performance of pin diodes prepared in a PECVD process with 10 % GeH4 in the gas phase is discussed. These results are compared with the characteristics of diodes prepared with higher germane content in the gas phase. With increasing germane content the solar cell parameters Voc and FF decrease and the deposition regime where good optoelectronic properties are observed is narrowed.

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Effect of Ge atoms on crystal structure and optoelectronic properties of hydrogenated Si–Ge films

Modern Physics Letters B ◽

10.1142/s0217984917400103 ◽

2017 ◽

Vol 31 (19-21) ◽

pp. 1740010 ◽

Cited By ~ 1

Author(s):

Tianwei Li ◽

Jianjun Zhang ◽

Ying Ma ◽

Yunwu Yu ◽

Ying Zhao

Keyword(s):

Silicon Germanium ◽

Amorphous Matrix ◽

Volume Fraction ◽

Defect Density ◽

Chemical Vapor ◽

Radio Frequency Plasma ◽

Microcrystalline Silicon ◽

Bond Density ◽

Hydrogen Dilution ◽

Frequency Plasma

Optoelectronic and structural properties of hydrogenated microcrystalline silicon–germanium ([Formula: see text]c-Si[Formula: see text]Ge[Formula: see text]:H) alloys prepared by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) were investigated. When the Ge atoms were predominantly incorporated in amorphous matrix, the dark and photo-conductivity decreased due to the reduced crystalline volume fraction of the Si atoms (X[Formula: see text]) and the increased Ge dangling bond density. The photosensitivity decreased monotonously with Ge incorporation under higher hydrogen dilution condition, which was attributed to the increase in both crystallization of Ge and the defect density.

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