Optoelectronics and Photovoltaic Applications of Microcrystalline Sic

1989 ◽  
Vol 164 ◽  
Author(s):  
Y. Hamakawa ◽  
Y. Matsumoto ◽  
G. Hirata ◽  
H. Okamoto
Keyword(s):  
Electron Cyclotron Resonance ◽  
Energy Gap ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Heterojunction Solar Cells ◽  
Plasma Chemical Vapor Deposition ◽  
Ecr Plasma ◽  
Valency Electron ◽  
P Type

AbstractA review is given of the electrical and optical properties of hydrogenated microcrystalline silicon carbide (μc-SiC:H) films prepared by ECR (Electron Cyclotron Resonance) plasma chemical vapor deposition. The material produced with the ECR plasma technology has a very wide energy gap from 2 to 2.8 eV with good valency electron controllability, e.g., a dark conductivity as high as 10 Scmg− which is more than seven orders of magnitude larger than that of amorphous SiC:H.Employing this material as a wide gap heterojunction window, 15.4% and 12.0% conversion efficiencies have been achieved with the structures of ITO/p type μc-SiC:H/n type poly-Si and p type vc-SiC:H/i type a-Si:H/n type Pc-Si:H heterojunction solar cells, respectively. The successful development of a visible light thin film light emitting diode show the promise of microcrystalline materials for optoelectronic applications.

Low Temperature Fabrication of (Ba, Sr)TiO3 Thin Films by ECR Plasma CVD

1996 ◽  
Vol 433 ◽  
Author(s):  
Y. Kato ◽  
H. Yabuta ◽  
S. Sone ◽  
H. Yamaguchi ◽  
T. Iizuka ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Mass Transport ◽  
Electron Cyclotron Resonance ◽  
Stoichiometric Composition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Equivalent Thickness ◽  
Plasma Chemical Vapor Deposition ◽  
Ecr Plasma ◽  
Metal Organic

AbstractPhysical and electrical properties are investigated for (Ba, Sr)TiO3 (BST) films prepared by electron cyclotron resonance (ECR) plasma chemical vapor deposition (CVD) at relatively low temperatures, between 450 °C and 500 °C. The crystallinity of BST, estimated by X-ray diffraction and from the grain size, is greatly improved when the temperature is raised from 450 °C to 500 °C. Also better crystallinity is obtained for films grown at a deposition rate of 1.1 nn/min than at 2.7 nm/min. The mass transport rates of metal organic sources under our deposition conditions are estimated. The BST film composition is precisely controlled using the results of the investigation on mass transport. At near stoichiometric composition, i.e., (Ba+Sr)/Ti=0.97, and Ba/(Ba+Sr)=0.4, the films grown at 500 °C are found to have the largest dielectric constant, measured using flat capacitors with Pt bottom electrodes. A dielectric constant of 160 is obtained for 27 nm thick films grown at 500 °C and at 1.1 nm/min, without post-deposition annealing. These films exhibit the smallest SiO2 equivalent thickness of 0.65 nm and a leakage current density of 4.6x10−7 A/cm2 at plus IV.

DEVELOPMENT OF HIGHLY CONDUCTIVE BORON-DOPED MICROCRYSTALLINE SILICON FILMS FOR APPLICATION IN SOLAR CELLS

2006 ◽  
Vol 20 (03) ◽  
pp. 303-314 ◽  
Author(s):  
QING-SONG LEI ◽  
ZHI-MENG WU ◽  
JIAN-PING XI ◽  
XIN-HUA GENG ◽  
YING ZHAO ◽  
...  
Keyword(s):  
Solar Cells ◽  
Substrate Temperature ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Silicon Films ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Boron Doped ◽  
Deposition Processes ◽  
P Type

We have examined the deposition of highly conductive boron-doped microcrystalline silicon (μc- Si:H ) films for application in solar cells. Depositions were conducted in a very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) chamber. In the deposition processes, various substrate temperatures (TS) were applied. Highly conductive p-type microcrystalline silicon films were obtained at substrate temperature lower than 210°C. The factors that affect the conductivity of the films were investigated. Results suggest that the dark conductivity, which was determined by the Hall mobility and carrier concentration, is influenced by the structure. The properties of the films are strongly dependent on the substrate temperature. With TS increasing, the dark conductivity (σd) increases initially; reach the maximum values at certain TS and then decrease. Also, we applied the boron-doped μc- Si:H as p-layers to the solar cells. An efficiency of about 8.5% for a solar cell with μc- Si:H p-layer was obtained.

Effects of Composition on the Microstructures and Optical Properties of Hydrogenated Amorphous Silicon Carbide Films Prepared by Electron Cyclotron Resonance Plasma Chemical Vapor Deposition

1999 ◽  
Vol 593 ◽  
Author(s):  
Lih-Hsiung Chan ◽  
Wei-Zen Chou ◽  
Lih-Hsin Chou
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Vapor Deposition ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Hydrogenated Amorphous ◽  
Resonance Plasma

ABSTRACTHydrogenated amorphous silicon carbide films (a -SiC:H) were prepared from CH4, SiH4, and Ar mixtures by Electron Cyclotron Resonance Plasma Chemical Vapor Deposition (ECR PCVD). The deposition of the thin films was proceeded with the following optimized conditions; microwave power: 900W, Ar flux : 90sccm, and total flux: 113.4 sccm. The substrate temperature was around 100∼120°C during deposition. For comparisons, the relative flux ratio of methane to silane was varied to produce thin films of different compositions to investigate the relationships between the associated compositions of films and their corresponding microstructures and optical properties. Moreover, both film's microstructures and their optical properties were analyzed to find out as to how they are interrelated. Furthermore, the surface morphology and amorphous microstructures were confirmed by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), respectively. And, x-ray Photoelectron Spectroscopy (XPS) was employed to study the relative atomic ratio of C to Si along with the bonding conditions in the thin films. Finally, the Hydrogen concentration and the amounts of C-H and Si-H bonds were determined by Fourier transform infrared spectroscopy(FTIR), while the optical properties were measured by optical spectrophotometer.

Effect of Boron Doping on Microcrystalline Germanium Carbon Thin Films

2007 ◽  
Vol 989 ◽  
Author(s):  
Yasutoshi YASHIKI ◽  
Seiichi KOUKETSU ◽  
Shinsuke MIYAJIMA ◽  
Akira YAMADA ◽  
Makoto KONAGAI
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Boron Doping ◽  
Dark Conductivity ◽  
Hot Wire ◽  
Boron Doped ◽  
Vapor Deposition Technique ◽  
Type C ◽  
P Type

AbstractEffects of boron doping on microcrystalline germanium carbon alloy (μc-Ge1-xCx:H) thin films have been investigated. We deposited boron-doped p-type μc-Ge1-xCx:H thin films by hot-wire chemical vapor deposition technique using hydrogen diluted monomethylgermane (MMG) and diborane (B2H6). A dark conductivity of 1.3 S/cm and carrier concentration of 1.7 x 1020 cm-3 were achieved with B2H6/MMG ratio of 0.1. Furthermore, the activation energy decreased from 0.37 to 0.037 eV with increasing B2H6/MMG ratio from 0 to 0.1. We also fabricated p-type μc-Ge1-xCx:H/n-type c-Si heterojunction diodes. The diodes showed rectifying characteristics. The typical ideality factor and rectifying ratio were 1.4 and 3.7 x 103 at ¡Ó 0.5 V, respectively.

Amorphous and Microcrystalline SiC as New Synthetic Wide Gap Semiconductors

1992 ◽  
Vol 242 ◽  
Author(s):  
Y. Hamakawa ◽  
H. Okamoto
Keyword(s):  
Energy Gap ◽  
Ion Beam ◽  
Technological Evolution ◽  
Microcrystalline Silicon ◽  
Technical Data ◽  
Preparation Conditions ◽  
Current State ◽  
Valency Electron ◽  
Impurity Doping ◽  
P Type

ABSTRACTA review is given on recent progress in amorphous and microcrystalline silicon-carbide (a-SiC, nc-SiC) semiconductors and their technological applications to optoelectronic functional devices. Firstly, some significant properties in this alloy as a new synthetic material are pointed out with recent advances of thin film technologies, such as plasma CVD, ECR-CVD and ion-beam CVD etc. There exists an energy gap controllability from 1.7eV to 3.6 eV with retaining the valency electron control from n-type through i- to p-type semiconductors. While its conductivity can also be controlled more than ten order of magnitudes, e.g., from 10-9to 102 Scm-1 by controlling the impurity doping and preparation conditions.Secondly, a series of technical data on the electronic and optoelectronic properties of a-Si, C1−x C1−x and μ-SiC are demonstrated from recent achievements. In the final part of the paper, current state of the art in the field of optoelectronic applications from live technologies on amorphous silicon solar cells. a-SiC visible light LED and EL devices are reviewed. A technological evolution from “microelectronics” to “macroelectronlcs” will be discussed.

Deposition of Diamond using an Electron Cyclotron Resonance Plasma System

1994 ◽  
Vol 339 ◽  
Author(s):  
Donald R. Gilbert ◽  
Rajiv Singh ◽  
W. Brock Alexander ◽  
Dong Gu Lee ◽  
Patrick Doering
Keyword(s):  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Electron Cyclotron ◽  
Plasma System ◽  
Electron Cyclotron Resonance Plasma ◽  
Ecr Plasma ◽  
Low Pressures ◽  
Substrate Temperatures ◽  
Resonance Plasma

ABSTRACTWe have used an electron cyclotron resonance plasma system to perform chemical vapor deposition experiments on single-crystal, (110) oriented diamond substrates. The depositions were carried out at 0.060 Torr using mixtures of methanol in hydrogen. Substrate temperatures were varied from approximately 620 to 800 °C The film morphology was examined using SEM and microstructural phase determination was attempted using micro-Raman spectroscopy. Based on the results of these experiments, we have determined general trends for the characteristics of films deposited on diamond from the ECR plasma at low pressures and temperatures.

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