1 / F Noise Measurements of Interacting Current Filaments in Hydrogenated Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
C.E. Parman ◽  
N.E. Israeloff ◽  
J. Fan ◽  
J. Kakalios
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Power Spectra ◽  
Noise Power ◽  
Switching Noise ◽  
Scale Invariant ◽  
Noise Sources ◽  
Noise Measurements ◽  
Current Filaments ◽  
Hydrogenated Amorphous

The coplanar current in n-lype doped hydrogenated amorphous silicon (a-Si:H) displays random telegraph switching noise, indicating the presence of inhomogeneous current filaments whose conductance varies with time. There are strong correlations of the 1/f noise power spectra across differing frequency octaves which are much larger than expected if the magnitudes of the fluctuators are varied in parallel. The scale invariant second spectra and the temperature dependence of the spectral slope indicate that hydrogen motion is involved in the cooperative dynamics between noise sources. A model is described wherein the properties of the current filaments are modulated by hydrogen-hydrogen interactions which are mediated by the Si strain fields.

Thermopower and 1/f Noise Measurements in Amorphous Silicon-Carbon Alloys

1995 ◽  
Vol 377 ◽  
Author(s):  
H. M. Dyalsingh ◽  
G. M. Khera ◽  
J. Kakalios
Keyword(s):  
Amorphous Silicon ◽  
Power Spectra ◽  
Carbon Films ◽  
Noise Power ◽  
Mobility Edge ◽  
Silicon Carbon ◽  
Noise Measurements ◽  
Noise Statistics ◽  
Hydrogenated Amorphous ◽  
Q Function

ABSTRACTThermopower, conductivity and 1/f noise measurements have been performed on a series of n-type doped hydrogenated amorphous silicon carbon films that are prepared with varying gas phase concentrations of CH4. The increased disorder at the mobility edge associated with alloying is characterized by the Q-function, which is obtained by combining thermopower and conductivity measurements, and is also reflected in the noise power spectra and noise statistics.

Telegraph Noise as A Probe of Microscopic Hydrogen Motion in Amorphous Silicon

1995 ◽  
Vol 377 ◽  
Author(s):  
Lisa M. Lust ◽  
J. Kakalios
Keyword(s):  
Amorphous Silicon ◽  
Diffusion Processes ◽  
Switching Noise ◽  
Resistor Network ◽  
Network Support ◽  
Conductance Fluctuations ◽  
Telegraph Noise ◽  
Current Filaments ◽  
Hydrogenated Amorphous ◽  
Dynamical Percolation

ABSTRACTTime traces of conductance fluctuations in the co-planar current of hydrogenated amorphous silicon (a-Si:H) display sharp jumps between discrete resistance levels, termed random telegraph switching noise (RTSN). Measurements of the temperature dependence and effects of light soaking of the RTSN in n-type doped a-Si:H are reported. The rise times between the two level fluctuators yield activation energies and attempt to hop frequencies for microscopic hydrogen motion which agree with those obtained from NMR experiments. Computer simulations of a dynamical percolation random resistor network support the suggestion that the RTSN arises from local diffusion processes altering the conductance of inhomogeneous current filaments.

Light Induced Changes in the Non-Gaussian Noise Statistics in Doped Hydrogenated Amorphous Silicon

1993 ◽  
Vol 297 ◽  
Author(s):  
J. Fan ◽  
J. Kakalios
Keyword(s):  
Amorphous Silicon ◽  
Gaussian Noise ◽  
Hydrogenated Amorphous Silicon ◽  
Noise Power ◽  
Defect Creation ◽  
Non Gaussian ◽  
Noise Statistics ◽  
Induced Changes ◽  
Many Body Interactions ◽  
Hydrogenated Amorphous

The power spectrum of coplanar current fluctuations in n-type doped hydrogenated amorphous silicon (a-Si:H) has been measured before and after metastable defect creation by light soaking. The average magnitude and spectral slope of the 1/f noise are not affected by illumination, however significant changes in the higher order statistics are observed. Associated with the decrease of conductivity upon light soaking (the Staebler-Wronski effect), there is a decrease in the correlation of the noise power which characterize the non-Gaussian noise in the annealed state. These changes in the noise statistics are reversible by annealing. The light-induced changes in the non-Gaussian statistics provide experimental support for models of light induced defect creation which involve long-ranged and many body interactions.

1/f Noise Measurements of Hydrogenated Amorphous Silicon-Carbon Alloys

1994 ◽  
Vol 336 ◽  
Author(s):  
H. M. Dyalsingh ◽  
G. M. Khera ◽  
J. Kakalios ◽  
C. C. Tsai ◽  
R. A. Street
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Mobility Edge ◽  
Silicon Carbon ◽  
Noise Measurements ◽  
Gaussian Statistics ◽  
Non Gaussian ◽  
P Type ◽  
Hydrogenated Amorphous ◽  
Carbon Concentrations

ABSTRACTMeasurements of the optical, electronic and 1/f noise properties for a series of n-type doped hydrogenated amorphous silicon carbide thin films with varying gas phase concentrations of CH4 are described. The increase in the optical absorption edge of the n-type a-SiCx:H films with the addition of carbon is slower than in p-type films. Studies of the variation in the non-Gaussian statistics which characterize the 1/f noise indicate that the disorder at the mobility edge is greater for films with higher carbon concentrations.

Non-Gaussian 1 / f Noise and Conductance Fluctuations in Hydrogenated Amorphous Silicon

1992 ◽  
Vol 258 ◽  
Author(s):  
C. E. Parman ◽  
N. E. Israeloff ◽  
J. Kakalios
Keyword(s):  
Spectral Analysis ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Current Fluctuations ◽  
Noise Power ◽  
Effective Volume ◽  
Conductance Fluctuations ◽  
Cooperative Dynamics ◽  
Non Gaussian ◽  
Hydrogenated Amorphous

ABSTRACTStatistical analysis of the 1/f noise power spectrum of co-planar current fluctuations in n-type doped hydrogenated amorphous silicon (a-Si:H) find that the noise arises from a small number of correlated fluctuators. The noise power displays a complicated time dependence with the noise power changing in both magnitude and as a function of frequency. Spectral analysis of these noise power fluctuations display an approximate 1/f frequency dependence. These results are surprising given the effective volume (∼10-7 cm3) of the sample, and indicate that cooperative dynamics govern conductance fluctuations in a-Si:H.

BONDING IN HYDROGENATED AMORPHOUS SILICON

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-773-C4-777 ◽  
Author(s):  
H. R. Shanks ◽  
F. R. Jeffrey ◽  
M. E. Lowry
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous

High Rate Deposition of Stable Hydrogenated Amorphous Silicon in Transition from Amorphous to Microcrystalline Silicon

2003 ◽  
Vol 762 ◽  
Author(s):  
Guofu Hou ◽  
Xinhua Geng ◽  
Xiaodan Zhang ◽  
Ying Zhao ◽  
Junming Xue ◽  
...  
Keyword(s):  
Phase Transition ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
High Rate ◽  
Very High Frequency ◽  
High Quality ◽  
Working Pressure ◽  
Hydrogen Dilution ◽  
Hydrogenated Amorphous

AbstractHigh rate deposition of high quality and stable hydrogenated amorphous silicon (a-Si:H) films were performed near the threshold of amorphous to microcrystalline phase transition using a very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The effect of hydrogen dilution on optic-electronic and structural properties of these films was investigated by Fourier-transform infrared (FTIR) spectroscopy, Raman scattering and constant photocurrent method (CPM). Experiment showed that although the phase transition was much influenced by hydrogen dilution, it also strongly depended on substrate temperature, working pressure and plasma power. With optimized condition high quality and high stable a-Si:H films, which exhibit σph/σd of 4.4×106 and deposition rate of 28.8Å/s, have been obtained.

Sign in / Sign up

Export Citation Format

Share Document