Revealing Structural Disorder in Hydrogenated Amorphous Silicon for a Low‐Loss Photonic Platform at Visible Frequencies

2021 ◽  
pp. 2005893
Author(s):  
Younghwan Yang ◽  
Gwanho Yoon ◽  
Sunghak Park ◽  
Seok Daniel Namgung ◽  
Trevon Badloe ◽  
...  
1993 ◽  
Vol 297 ◽  
Author(s):  
A.J.M. Berntsen ◽  
P.A. Stolk ◽  
W.F. VAN DER WEG ◽  
F.W. Saris

Hydrogenated amorphous silicon (a-Si:H) films were irradiated with 1-MeV Si+ ions. The accumulation and annealing of ion damage was investigated by Raman scattering, optical reflection and transmission, and conductivity measurements. For damage levels up to 0.003 displacements per atom, electrical defects are created with no measurable effect on the structural properties. These defects can be completely annealed out at 180°C. Further irradiation results in an increase in the average bond-angle variation in the films. This structural disorder causes a decrease of the optical band gap with 0.46 eV. The structural changes caused by high-dose implantation can not be reversed by annealing at 180° C, which results in the formation of anneal-stable electrical defects.


1998 ◽  
Vol 73 (21) ◽  
pp. 3093-3095 ◽  
Author(s):  
J. M. Gibson ◽  
M. M. J. Treacy ◽  
P. M. Voyles ◽  
H-C. Jin ◽  
J. R. Abelson

1992 ◽  
Vol 258 ◽  
Author(s):  
A. J. M. Berntsen ◽  
M. J. Van Den Boogaard ◽  
W. G. J. H. M. Van Sark ◽  
W. F. Van Der Weg

ABSTRACTA series of hydrogenated amorphous silicon (a-Si:H) films was deposited by rf glow-discharge deposition using various processing conditions. We have studied microstructure in the films by means of infrared absorption spectroscopy. Small-angle X-ray scattering measurements were used to determine the microvoid fractions of a few selected samples. Our results show that both the void fraction and the amount of microstructure can be varied either by changing the substrate temperature or by H2 dilution. Bond-angle variation in the films was probed by Raman scattering measurements. The Raman data indicate that the substrate temperature is the main variable that determines the bond-angle variation. We conclude that the presence of microvoids in a-Si:H does not influence the structural disorder of the amorphous matrix surrounding the voids. Our results are in agreement with experimental work on microvoids in a-Si1-xCx:H, and model calculations on voids in a-Si.


1998 ◽  
Vol 507 ◽  
Author(s):  
K. Shimizu ◽  
T. Tabuchi ◽  
K. Hattori ◽  
H. Kida ◽  
H. Okamoto

ABSTRACTPolarized electroabsorption method has been used to study photo-induced structural changes in hydrogenated amorphous silicon. The field-modulated absorption signal consists of two components, one of which is the true polarization-dependent electroabsorption serving as an indicator of the structural disorder, and the other is the thermoabsorption resulted from the temperature modulation due to Joule heating. The thermoabsorption component has removed from the observed field-modulated absorption signal to make an accurate and reliable evaluation of structural disorder by phase-separation procedure. As a result, about 15-25 % of the observed signal arises from the thermoabsorption effect for the Tauc gap region. Nevertheless, any essential alteration is not needed for our previous PEA results. The internal stress as well as density have been measured to provide another evidences for the photo-induced structural change. It is found that amorphous silicon film expands and the density tends to decrease upon light-exposure, the temporal behaviors of which coincide with that of the PEA ratio factor indicating disorderness of the amorphous network structure. The results permit us to conclude that a large scaled change in the amorphous network structure occurs under light-exposure, which might proceed the light-induced creation of metastable dangling bond defects.


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