Electronic and Structural Characterization of the Near Surface Layer and the Bulk in νc-Si:H Prepared with Hydrogen dilution

1989 ◽  
Vol 164 ◽  
Author(s):  
Samer Aljishi ◽  
Shu Jin ◽  
Martin Stutzmann ◽  
Lothar Ley
Keyword(s):  
Hydrogen Bonding ◽  
Surface Layer ◽  
Optical Absorption ◽  
Structural Characterization ◽  
Defect Density ◽  
Total Yield ◽  
High Hydrogen ◽  
Near Surface ◽  
Hydrogen Dilution

AbstractThe near surface layer and the bulk of νc-Si:H prepared with hydrogen dilution are investigated by Raman, optical absorption, and total yield photoelectron spectroscopies. The results show that for low hydrogen dilution ratios, microcrystallites appear in the bulk while the growing surface layer remains amorphous, indicating that microcrystallite formation takes place primarily in the sub-surface layer. At high hydrogen dilution ratios, microcrystallites are detected at both the bulk and the near surface layer. The defect density and hydrogen bonding configurations at various hydrogen dilution levels are presented.

Material Basis of Highly Stable a-Si:H Solar Cells

1996 ◽  
Vol 420 ◽  
Author(s):  
B. Rech ◽  
S. Wieder ◽  
F. Siebke ◽  
C. Beneking ◽  
H. Wagner
Keyword(s):  
Defect Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
High Hydrogen ◽  
Interface Recombination ◽  
Hydrogen Dilution ◽  
Process Gas ◽  
Current Densities ◽  
Comprehensive Characterization

AbstractWe achieved a stabilized efficiency of 9.2 % after only 8 % relative degradation for an a-Si:H/a-Si:H stacked cell with the top-cell i-layer prepared at 140 °C using a high hydrogen dilution of the silane process gas. From a comprehensive characterization of p-i-n cells and the corresponding i-layer material prepared at 140 °C and 190 °C substrate temperature with different hydrogen dilutions, we conclude that the performance of these pin cells strongly correlates with the material properties of the corresponding i-layers. High fill factors after light soaking are reflected in a good microstructure, high photo-conductivity, and relatively low defect density. Whereas the initial Voc is limited by interface recombination, volume recombination dominates the forward-dark current after light soaking. The stabilized Voc as well as the short-circuit current densities correlate with the optical bandgap of the i-layer.

Hot-Wire CVD Poly-Silicon Films for Thin Film Devices

1998 ◽  
Vol 507 ◽  
Author(s):  
J.K. Rath ◽  
F.D. Tichelaar ◽  
H. Meiling ◽  
R.E.I. Schropp
Keyword(s):  
Defect Density ◽  
Initial Growth ◽  
Oriented Growth ◽  
Compact Structure ◽  
High Hydrogen ◽  
New Approach ◽  
Intrinsic Nature ◽  
Bias Stress ◽  
Hydrogen Dilution ◽  
Long Duration

ABSTRACTSolar cell using profiled poly-Si:H by HWCVD as i-layer in the configuration SS/n-µSi:H(PECVD)/i-poly-Si:H(HWCVD)/p-µc-Si:H(PECVD)/ITO showed 3.7% efficiency. A current of 23.6 mA/cm2 was generated in only 1.5 µm thick poly-Si:H i-layer grown at ∼5Å/s. TFTs made with the poly-Si:H films (grown at ≥ 9Å/s) exhibited remarkable stability to long duration of 23 hours of gate bias stress of ∼lMV/cm. A saturation mobility of 1.5 cm2/Vs for the TFT has been achieved. Films made at low hydrogen dilution (Poly2) showed device quality (purely intrinsic nature, ambipolar diffusion length of 568 nm, only (220) oriented growth and low ESR defect density of <1017/cm3with complete absence of signal due to conduction electrons) but with an incubation phase of amorphous initial growth, whereas the films made at high hydrogen dilution (Polyl) had a polycrystalline initial growth, though with higher defect density, incorporated oxygen and randomly oriented grains. Poly2 films are compact and hydrogen bonding is at compact Si-H sites manifested as 2000 cm−1IR vibration and high temperature hydrogen evolution peak. Exchange interaction of spins and spin pairing are observed while increasing defects in such a compact structure. A new approach has been used to integrate these two regimes of growth to make profiled poly-Si:H layers. The new layers show good electronic properties as well as complete elimination of incubation phase.

Optical absorption and structural characterization of reactively sputtered tellurium suboxide thin films

1993 ◽  
Vol 65-66 ◽  
pp. 313-318 ◽  
Author(s):  
M. Di Giulio ◽  
M.C. Nicotra ◽  
M. Re ◽  
R. Rella ◽  
P. Siciliano
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Structural Characterization

scholarly journals Structural Characterization of Fine γ′-Fe4N Nitrides Formed by Active Screen Plasma Nitriding

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1656
Author(s):  
Jaroslaw Jan Jasinski ◽  
Lukasz Kurpaska ◽  
Tadeusz Fraczek ◽  
Malgorzata Lubas ◽  
Maciej Sitarz
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Characterization ◽  
Plasma Nitriding ◽  
Nitrogen Concentration ◽  
Grazing Incidence ◽  
Model Material ◽  
Active Screen Plasma Nitriding ◽  
Active Screen

The paper presents the structural characterization of γ′-Fe4N nitrides produced by active screen plasma nitriding (ASPN) processes. Experiments were performed on the Fe-Armco model material at 693, 773, and 853 K for 6 h. Investigation of the properties of the substrate was realized using scanning electron microscopy (SEM, SEM–EBSD/Kikuchi lines), energy-filtered transmission electron microscopy (TEM-EFTEM), X-ray diffraction (GID, grazing incidence diffraction, micro-XRD), and secondary ion mass spectroscopy (SIMS). Results have confirmed that the γ′-Fe4N nitrides’ structure and morphology depend considerably on the nitriding process’s plasma conditions and cooling rate. In addition to that, γ′-Fe4N nitrides’ formation can be correlated with the surface layer saturation mechanism and recombination effect. It has been shown that the γ′-Fe4N structure depends considerably on several phenomena that occur in the diffusive layer (e.g., top layer decomposition, nitrogen, and carbon atoms’ migration). Our research proves that the nitrogen concentration gradient is a driving force of nitrogen migration atoms during the recombination of γ′-Fe4N nitrides. Finally, realized processes have allowed us to optimize active screen plasma nitriding to produce a surface layer of fine nitrides.

Structure and Dynamics of 9(10H)-Acridone and Its Hydrated Clusters. II. Structural Characterization of Hydrogen-Bonding Networks

2000 ◽  
Vol 104 (38) ◽  
pp. 8649-8659 ◽  
Author(s):  
Masaaki Mitsui ◽  
Yasuhiro Ohshima ◽  
Shun-ichi Ishiuchi ◽  
Makoto Sakai ◽  
Masaaki Fujii
Keyword(s):  
Hydrogen Bonding ◽  
Structural Characterization ◽  
Structure And Dynamics ◽  
Hydrogen Bonding Networks ◽  
Hydrated Clusters

Synthesis and structural characterization of tube-type tetradecavanadates

2018 ◽  
Vol 74 (11) ◽  
pp. 1295-1299 ◽  
Author(s):  
Sho Kuwajima ◽  
Yuta Arai ◽  
Hiromasa Kitajima ◽  
Yuji Kikukawa ◽  
Yoshihito Hayashi
Keyword(s):  
Hydrogen Bonding ◽  
Dimethyl Sulfoxide ◽  
Ammonium Perchlorate ◽  
Structural Characterization ◽  
Equatorial Plane ◽  
Noncovalent Interactions ◽  
Rotation Axes ◽  
Hydrogen Bonding Interactions ◽  
Tube Type

By the reaction of ammonium perchlorate with anion-incorporated bowl-type dodecavanadates, viz. [V12O32(X)]5− [X = N3 − (1), OCN− and NO3 −], tube-type tetradecavanadates, viz. (NH4)7[V14O38(X)] [X = N3 − (2), OCN− (3) and NO3 − (4)] were synthesized. The crystal structures of penta(tetraethylammonium) azidododecavanadate nitromethane monosolvate, (C8H20N)5[V12O32(N3)]·CH3NO2, 1, heptaammonium azidotetradecavanadate dimethyl sulfoxide hexasolvate, (NH4)7[V14O38(N3)]·6C2H6OS, 2, heptaammonium cyanatotetradecavanadate dimethyl sulfoxide hexasolvate, (NH4)7[V14O38(OCN)]·6C2H6OS, 3, and heptaammonium nitratotetradecavanadate dimethyl sulfoxide hexasolvate, (NH4)7[V14O38(NO3)]·6C2H6OS, 4, were determined. The tube consists of two layers of V7 rings with a guest anion at the centre. The distances between the incorporated anions and the nearest V atoms are 3.058 (3), 3.039 (6) and 2.811 (9) Å for 2, 3 and 4, respectively, showing that the incorporated anions are stabilized via noncovalent interactions. Two ammonium cations cap both ends of the tube to stabilize the structures via hydrogen-bonding interactions. Linear OCN− and N3 − anions sit on the twofold rotation axes of the tube frameworks and the triangular plane of the NO3 − anion deviates from the equatorial plane of the tube by ca 30°.

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