Measurements of the Transient Photoconductivity During the Growth of A-Si:H Multilayers

1990 ◽  
Vol 192 ◽  
Author(s):  
H. C. Neitzert ◽  
A. Werner ◽  
W. Kunst ◽  
M. Kunst
Keyword(s):  
Amorphous Silicon ◽  
Doping Concentration ◽  
Film Growth ◽  
Hydrogenated Amorphous Silicon ◽  
Deposition Process ◽  
Transient Photoconductivity ◽  
Multiple Layer ◽  
Layer Structures ◽  
P Type ◽  
Hydrogenated Amorphous

ABSTRACTThe deposition process of multiple layer structures of intrinsic and p-type hydrogenated amorphous silicon was followed by measuring the microwave detected transient photoconductivity (TRMC) during the film growth. In an i-p-i structure we can show that after deposition of an upper layer of about 500 nm, former deposited layers do not influence the TRMC-signal any more. In an i-p+-i-p structure we can clearly distinguish between p-layers of different doping concentration.

Effect of B Boping Concentration on the Properties of P-Type Hydrogenated Amorphous Silicon Thin Films

2011 ◽  
Vol 239-242 ◽  
pp. 247-251
Author(s):  
Wei Yuan Wang ◽  
Qing Nan Zhao ◽  
Wen Hui Yuan ◽  
Pu Lei Yang ◽  
Hong Yu Liang ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Band Gap ◽  
Doping Concentration ◽  
Optical Band Gap ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Float Glass ◽  
B Doping ◽  
P Type ◽  
Hydrogenated Amorphous

P-type hydrogenated amorphous silicon films were deposited on float glass substrates by plasma enhanced chemical vapor deposition (PECVD). The effect of B doping concentration on the properties of the films was studied. The structure of the films was investigated by X-ray diffraction (XRD). The transmittance of the films was measured using an UV–Vis–NIR spectrophotometer in the wavelength range 200–2600nm.The film thickness was fitted by NKD-7000W optical thin film analysis system. The optical band gap of the films was obtained by the Tauc method. The conductivity of the films was tested by Electrometer Keithley 6517B. The results show that the optical band gap of the films changes from 1.93 eV to 1.65eV with the increase of B doping concentration, the highest conductivity of the film doped with 1.86% B2H6is 7.82 × 10-4S/cm.

Reduction of the Defect Density in a-Si:H Deposited at ≤250°C

1993 ◽  
Vol 297 ◽  
Author(s):  
Hitoshi Nishio ◽  
Gautam Ganguly ◽  
Akihisa Matsuda
Keyword(s):  
Diffusion Coefficient ◽  
Amorphous Silicon ◽  
Surface Diffusion ◽  
Film Growth ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Device Fabrication ◽  
Surface Diffusion Coefficient ◽  
Hydrogenated Amorphous ◽  
Substrate Temperatures

We present a method to reduce the defect density in hydrogenated amorphous silicon (a-Si:H) deposited at low substrate temperatures similar to those used for device fabrication . Film-growth precursors are energized by a heated mesh to enhance their surface diffusion coefficient and this enables them to saturate more surface dangling bonds.

Semiconducting Polymer and Hydrogenated Amorphous Silicon Heterojunction Solar Cells

2011 ◽  
Vol 1321 ◽  
Author(s):  
A. R. Middya ◽  
Eric A. Schiff
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Photovoltaic Effect ◽  
Hydrogenated Amorphous Silicon ◽  
Hybrid Solar Cells ◽  
Semiconducting Polymer ◽  
Heterojunction Solar Cells ◽  
P Type ◽  
Hydrogenated Amorphous ◽  
Silicon Heterojunction Solar Cells

ABSTRACTIn this work, we report on investigation of p-type semiconducting polymer, {poly(3,4 polyethylenedioxythiophene)-poly(styrenesulfonate)} (PEDOT:PSS) as the p-layer in NIP and PIN hydrogenated amorphous silicon (a-Si:H) solar cells. The rectification ratio of solution-casted diode is ∼ 10, it increases to 3×104 when PEDOT:PSS is deposited by Spin Coating technique. We observed additional photovoltaic effect when light is illuminated through polymer side. So far, best solar cells characteristics observed for PEDOT:PSS/a-Si:H hybrid solar cells are Voc ≈ 720 mV and Jsc ≈ 1 - 2 mA/cm2.

Boron doping in a-SiO:H,

2014 ◽  
Vol 92 (7/8) ◽  
pp. 586-588 ◽  
Author(s):  
Y. Kitani ◽  
T. Maeda ◽  
S. Kakimoto ◽  
K. Tanaka ◽  
R. Okumoto ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Hole Mobility ◽  
Boron Doping ◽  
Type A ◽  
Dark Conductivity ◽  
Wide Range ◽  
P Type ◽  
Hydrogenated Amorphous ◽  
Silicon Oxygen

Boron-doping characteristics in hydrogenated amorphous silicon–oxygen alloys (a-SiO:H) have been studied in contrast to those in hydrogenated amorphous silicon (a-Si:H). Although the boron-incorporation efficiency shows almost the same value between a-SiO:H and a-Si:H, p-type a-SiO:H (p-a-SiO:H) exhibits lower dark conductivity by one or two orders of magnitude as compared to p-type a-Si:H (p-a-Si:H) in a wide range of doping levels. We have found that p-a-SiO:H exhibits low dark conductivity as compared to p-a-Si:H even when we choose samples showing the same activation energy from a variety of as-deposited and thermally annealed samples. We have concluded from the different Urbach-energy values between high quality intrinsic a-SiO:H and a-Si:H that the origin of low dark conductivity in p-a-SiO:H is due to low hole mobility.

High Performance Hydrogenated Amorphous Silicon n-i-p Photo-diodes on Glass and Plastic Substrates by Low-temperature Fabrication Process

2007 ◽  
Vol 989 ◽  
Author(s):  
Kyung Ho Kim ◽  
Yuriy Vygranenko ◽  
Mark Bedzyk ◽  
Jeff Hsin Chang ◽  
Tsu Chiang Chuang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Amorphous Silicon ◽  
High Performance ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Plastic Substrate ◽  
Process Conditions ◽  
Plastic Substrates ◽  
Hydrogenated Amorphous

AbstractWe report on the fabrication and characterization of hydrogenated amorphous silicon (a-Si:H) films and n-i-p photodiodes on glass and PEN plastic substrates using low-temperature (150°C) plasma-enhanced chemical vapor deposition. Process conditions were optimized for the i-a-Si:H material which had a band gap of ~1.73 eV and low density of states (of the order 1015 cm-3). Diodes with 0.5 μm i-layer demonstrate quantum efficiency ~70%. The reverse dark current of the diodes on glass and PEN plastic substrate is ~10-11 and below 10-10 A/cm2, respectively. We discuss the difference in electrical characteristics of n-i-p diodes on glass and PEN in terms of bulk- and interface-state generation currents.

scholarly journals Anisotropy in Hydrogenated Amorphous Silicon Films as Observed Using Polarized Ftir-Atr Spectroscopy

1999 ◽  
Vol 557 ◽  
Author(s):  
J. D. Webb ◽  
L. M. Gedvilas ◽  
R. S. Crandall ◽  
E. Iwaniczko ◽  
B. P. Nelson ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Film Growth ◽  
Crystalline Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Impurity Band ◽  
Attenuated Total Reflection ◽  
Structural Anisotropy ◽  
Si Films ◽  
Polarized Ftir ◽  
Hydrogenated Amorphous

AbstractWe used polarized attenuated total reflection (ATR) measurements together with Fourier transform infrared (FTIR) spectroscopy to investigate the vibrational spectra of hydrogenated amorphous silicon (a-SiHx) films 0.5-1.0 microns in thickness. We deposited the films using hot-wire or plasma-enhanced chemical vapor deposition methods (HWCVD or PECVD, respectively) on crystalline silicon and cadmium telluride substrates. Our ATR technique gave a spectral range from 2100-400 cm-1, although the Si-H wagging mode absorption band at 640 cm-1 was somewhat distorted in the a-SiHx/Si samples by impurity and lattice absorption in the silicon ATR substrates. We report the identification of a Si-O-C impurity band with maximum intensity at 1240-1230 cm-1. The assignment of this band to a Si-O-C vibration is supported by secondary-ion mass spectrometry (SIMS) measurements. Our polarized FTIR-ATR spectra of HWCVD and PECVD a-SiHx films on <111> Si ATR substrates show that the impurity dipoles are oriented strongly parallel to the film growth direction. The wagging mode absorbance band is more intense in the film plane. This trend is less pronounced for the Si-H stretching vibrations. These observations are consistent with some degree of anisotropy or medium-range order in the films. The anisotropy in the Si-H bands may be related to residual stress in the films. Our scanning electron microscopy (SEM) analyses of the samples offer additional evidence of bulk structural anisotropy in the a-SiHx/Si films. However, the Si-O-C impurity band was not observed in the polarized ATR-FTIR spectra of the a-SiHx/CdTe samples, thus indicating that the Si substrates influence formation of the impurity in the a-SiHx/Si films.

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