Microcrystal Si Films Prepared by Remote Plasma CVD

1989 ◽  
Vol 164 ◽  
Author(s):  
Sung Chul Kim ◽  
Jung Tae Hwang ◽  
Seung Kyu Lee ◽  
Chang Young Jung ◽  
Sung Moo Soe ◽  
...  
Keyword(s):  
Rf Power ◽  
Plasma Cvd ◽  
Remote Plasma ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Hydrogen Dilution ◽  
Power Yield ◽  
Si Films ◽  
Hydrogen Radicals ◽  
P Type

AbstractThe effects of deposition temperature, rf power and hydrogen dilution ratio on the growth, structure and transport of p-type microcrystal(μc-) Si films deposited by remote plasma CVD have been investigated. While low substrate temperature and low rf power yield small grain sizes, high temperature and high rf power tend to supress the growth of grains. The etching of Si by hydrogen radicals plays an important role to grow μc-Si, but excess etching supresses the growth of crystallites. We obtained 400 A of grain size and 3.5 S/cm of room temperature conductivity for p-type μ-Si.

Fabrication of Undoped and N+ Microcrystalline si Films Using SiH2Ci2

1995 ◽  
Vol 377 ◽  
Author(s):  
Jae Seong Byun ◽  
Hong Bin Jeon ◽  
Jung Mok Jun ◽  
Jae Ho Yoo ◽  
Kyung Ha Lee ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Volume Fraction ◽  
Crystalline Volume Fraction ◽  
Plasma Cvd ◽  
Conductivity Activation Energy ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Si Films

ABSTRACTWe have studied the growth of undoped and n+ μc-Si:H (:CI) films by Remote Plasma CVD using SiH4/SiH2Cl2/H2/He mixtures. It was found that the μc-Si film can be fabricated by increasing flow rate of SiH2Cl2 and/or H2. The deposited undoped μc-Si film exhibited a maximum crystalline volume fraction of 85 %, obtained from Raman spectroscopy. The n-type μc-Si film, deposited with SiH4/SiH2Cl2/H2/PH3/He mixtures, shows a room temperature conductivity of 2 S/cm, conductivity activation energy of 29.8 meV and optical band gap of-2.0 eV. The optical band gap of n-type μc-S1 deposited using SiH2Cl2 is much higher compared to conventional μc-Si film.

Synthesis, Electrical and Humidity Sensing Properties of BaTiO3 Nanofibers via Electrospinning

2011 ◽  
Vol 418-420 ◽  
pp. 684-687 ◽  
Author(s):  
Hong Di Zhang ◽  
Yun Ze Long ◽  
Zhao Jian Li ◽  
Bin Sun ◽  
Chen Hao Sheng
Keyword(s):  
Room Temperature ◽  
Humidity Sensor ◽  
Annealing Process ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Humidity Sensing ◽  
P Type ◽  
Application Prospects ◽  
Humidity Sensing Properties ◽  
Scanning Electron

Barium titanate (BTO, BaTiO3) nanofiber was prepared via electrospinning and followed annealing process. The as-spun and calcined BTO nanofibers were characterized by a scanning electron microscope (SEM). After annealing at 800 °C in air for 3 h, polycrystalline BTO nanofibers with 120-200 nm in diameter were successfully obtained. I-V characteristic curves of single BTO nanofiber were measured. The p-type semiconducting fiber shows a room-temperature conductivity of about 0.3 S/cm. In addition, the small humidity hysteresis demonstrates the application prospects of electrospun BTO nanofibers in the fabrication of a high-sensitive humidity sensor.

¼c Silicon Thin Films Deposited by Remote Plasma Enhanced Chemical Vapor Deposition Process

1990 ◽  
Vol 192 ◽  
Author(s):  
C. Wang ◽  
G. N. Parsons ◽  
S. S. Kim ◽  
E. C. Buehler ◽  
R. J. Nemanich ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Substrate Material ◽  
Degree Of Crystallinity ◽  
Silicon Thin Films ◽  
Hydrogen Dilution ◽  
Type C ◽  
Si Films ◽  
P Type

ABSTRACTIn an earlier study, we deposited ¼c-Si thin films by reactive magnetron sputtering (RMS). Here we extend our studies to the deposition of both undoped and high conductivity N-type and P-type ¼c-Si thin films by a remote PECVD. We show that ¼c-Si films can be deposited by bringing hydrogen, H2, into the source gas mixtures. The H2 could introduced by either upstream in a He/H2 mixture and directly plasma excited, or downstream, and be remotely excited along with the silane, SiH4, feed gas. The degree of crystallinity is shown to depend on the hydrogen dilution, the substrate temperature and the substrate material.

Hydrogenated Silicon Films Prepared by Remote Plasma CVD

1990 ◽  
Vol 192 ◽  
Author(s):  
Sung Chul Kim ◽  
Seung Kyu Lee ◽  
Sung Mo Soe ◽  
Sung Ok Koh ◽  
Sung Shil Ihm ◽  
...  
Keyword(s):  
Chemical Vapour ◽  
Substrate Bias ◽  
Rf Power ◽  
Remote Plasma ◽  
Substrate Bias Voltage ◽  
Hydrogenated Silicon ◽  
Gas Concentration ◽  
Hydrogen Dilution ◽  
Plasma Chemical Vapour Deposition

ABSTRACTWe have studied the improvement of the quality of undoped a-Si:H deposited by remote-plasma chemical vapour deposition. The effects of reactant gas concentration, rf power, substrate bias voltage on the electrical and optical properties have been investigated. Some hydrogen dilution of si lane improves the photoeletric property and a high rf power gives rise to the defect creation due to the ion bombardment on the growing surface. The positive substrate bias improves the quality of undoped a-Si:H.

Preparation of SiC Thin Film Using Organosilicon by Remote Plasma CVD Method

1998 ◽  
Vol 544 ◽  
Author(s):  
Ying-Yu Xu ◽  
Takahiro Muramatsu ◽  
Toru Aoki ◽  
Yoichiro Nakanishi ◽  
Yoshinori Hatanaka
Keyword(s):  
Thin Film ◽  
Film Deposition ◽  
Plasma Cvd ◽  
Remote Plasma ◽  
Cvd Method ◽  
Gas Source ◽  
Thin Film Preparation ◽  
Hydrogen Radicals ◽  
Deposited Film ◽  
Deposited Films

AbstractAn organosilicon compound, hexamethyldisilane (HMDS) was incorporated for SiC thin film preparation by remote plasma enhanced CVD method. We investigated how plasma excited radicals react with source monomers using two kinds of gas mixtures. It was found that film component and formation mechanism depends on stronger on plasma gases. Using a mixture of nitrogen and hydrogen gases as plasma gas source, deposited films contained large amounts of nitrogen. When uing an argon and hydrogen mixture, deposited film was a SiC with large hydrogen contents. In this research, we found that hydrogen radicals are very active for decomposition of monomer source gas and this can be related to precursors for film deposition. When using a mixture of argon and hydrogen as plasma gas, the film deposition speed was influenced by substrate temperature. The estimated activation energy was larger than the case of using nitrogen and hydrogen gases. Different reaction mechanisms were observed for different plasma gas source

a-Si:N:H prepared by reactive evaporation in ammonia vapour

1987 ◽  
Vol 65 (8) ◽  
pp. 1020-1022
Author(s):  
R. D. Audas ◽  
D. E. Brodie
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Activation Energies ◽  
High Activation ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Reactive Evaporation ◽  
Ammonia Vapour ◽  
Optical Bandgaps ◽  
P Type

The reactive evaporation of Si in an ammonia ambient has been used to produce a-Si:N:H thin films. These films are "intrinsic-like" with low room-temperature conductivities (<10−12 S∙cm−1), high activation energies (0.9 eV), and high optical bandgaps (1.9 eV). Films prepared in this manner have been doped using co-evaporation of antimony (n type) and indium (p type). The addition of 2 at.% indium or antimony results in an increase in the room-temperature conductivity by eight and six orders of magnitude respectively. The undoped and doped samples are photoconductive when illuminated with a quartz-halogen source.

Fabrication of devices using vacuum deposited a–Si

1989 ◽  
Vol 67 (4) ◽  
pp. 195-198 ◽  
Author(s):  
R. D. Audas ◽  
D. E. Brodie
Keyword(s):  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Reactive Evaporation ◽  
Boron Doped ◽  
Optical Bandgaps ◽  
Temperature Activation ◽  
P Type ◽  
Phosphorus Doped ◽  
Term Objective

The long-term objective of this work is to produce a stable, efficient amorphous Si (a-Si) solar cell by a safe and inexpensive method. A process of reactive evaporation in a silane ambient was developed. This technique permits the fabrication of "intrinsic-like" a-Si:H. p-Type and n-type samples (carrier type was confirmed by Seebeck measurements) were prepared by the coevaporation of boron or reactive evaporation in a phosphorus ambient. The intrinsic-like samples have a room temperature conductivity of about 2 × 10−12 S cm−1, high temperature activation energies of 0.9 eV, and optical bandgaps near 1.8 eV. An all-amorphous Si:H pin diode was fabricated using this reactive evaporation process. The device consists of a tantalum contact, 20 – 40 nm of phosphorus doped a-Si:H, 300 – 400 nm of undoped a-Si:H, 20 – 40 nm of boron doped a-Si:H, and another tantalum contact.

scholarly journals Room-temperature synthesized copper iodide thin film as degenerate p-type transparent conductor with a boosted figure of merit

2016 ◽  
Vol 113 (46) ◽  
pp. 12929-12933 ◽  
Author(s):  
Chang Yang ◽  
Max Kneiβ ◽  
Michael Lorenz ◽  
Marius Grundmann
Keyword(s):  
Thin Films ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Visible Spectral Range ◽  
Transparent Conductors ◽  
Transparent Conductor ◽  
Temperature Dependent ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
P Type

A degenerate p-type conduction of cuprous iodide (CuI) thin films is achieved at the iodine-rich growth condition, allowing for the record high room-temperature conductivity of ∼156 S/cm for as-deposited CuI and ∼283 S/cm for I-doped CuI. At the same time, the films appear clear and exhibit a high transmission of 60–85% in the visible spectral range. The realization of such simultaneously high conductivity and transparency boosts the figure of merit of a p-type TC: its value jumps from ∼200 to ∼17,000 MΩ−1. Polycrystalline CuI thin films were deposited at room temperature by reactive sputtering. Their electrical and optical properties are examined relative to other p-type transparent conductors. The transport properties of CuI thin films were investigated by temperature-dependent conductivity measurements, which reveal a semiconductor–metal transition depending on the iodine/argon ratio in the sputtering gas.

scholarly journals Old Donors for New Molecular Conductors: Combining TMTSF and BEDT-TTF with Anionic (TaF6)1−x/(PF6)x Alloys

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 386
Author(s):  
Magali Allain ◽  
Cécile Mézière ◽  
Pascale Auban-Senzier ◽  
Narcis Avarvari
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Density Wave ◽  
Spin Density Wave ◽  
Orthorhombic Phase ◽  
Molecular Conductors ◽  
Bechgaard Salts ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
Resistivity Measurements

Tetramethyl-tetraselenafulvalene (TMTSF) and bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) are flagship precursors in the field of molecular (super)conductors. The electrocrystallization of these donors in the presence of (n-Bu4N)TaF6 or mixtures of (n-Bu4N)TaF6 and (n-Bu4N)PF6 provided Bechgaard salts formulated as (TMTSF)2(TaF6)0.84(PF6)0.16, (TMTSF)2(TaF6)0.56(PF6)0.44, (TMTSF)2(TaF6)0.44(PF6)0.56 and (TMTSF)2(TaF6)0.12(PF6)0.88, together with the monoclinic and orthorhombic phases δm-(BEDT-TTF)2(TaF6)0.94(PF6)0.06 and δo-(BEDT-TTF)2(TaF6)0.43(PF6)0.57, respectively. The use of BEDT-TTF and a mixture of (n-Bu4N)TaF6/TaF5 afforded the 1:1 phase (BEDT-TTF)2(TaF6)2·CH2Cl2. The precise Ta/P ratio in the alloys has been determined by an accurate single crystal X-ray data analysis and was corroborated with solution 19F NMR measurements. In the previously unknown crystalline phase (BEDT-TTF)2(TaF6)2·CH2Cl2 the donors organize in dimers interacting laterally yet no organic-inorganic segregation is observed. Single crystal resistivity measurements on the TMTSF based materials show typical behavior of the Bechgaard phases with room temperature conductivity σ ≈ 100 S/cm and localization below 12 K indicative of a spin density wave transition. The orthorhombic phase δo-(BEDT-TTF)2(TaF6)0.43(PF6)0.57 is semiconducting with the room temperature conductivity estimated to be σ ≈ 0.16–0.5 S/cm while the compound (BEDT-TTF)2(TaF6)2·CH2Cl2 is also a semiconductor, yet with a much lower room temperature conductivity value of 0.001 to 0.0025 S/cm, in agreement with the +1 oxidation state and strong dimerization of the donors.

scholarly journals Synthesis and Characterization of Lithium-Ion Conductive LATP-LaPO4 Composites Using La2O3 Nano-Powder

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai
Keyword(s):  
Room Temperature ◽  
Conduction Mechanism ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Nano Powder ◽  
Powder Addition

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.

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