scholarly journals Hydrogen desorption in SiGe films: A diffusion limited process

1997 ◽  
Vol 70 (24) ◽  
pp. 3287-3289 ◽  
Author(s):  
J. Vizoso ◽  
F. Martín ◽  
J. Suñé ◽  
M. Nafría
2001 ◽  
Vol 685 ◽  
Author(s):  
P. Louro ◽  
Yu. Vygranenko ◽  
M. Fernandes ◽  
M. Vieira ◽  
M. Schubert

AbstractA series of large area single layers and heterojunction cells in the assembly glass/ZnO:Al/p (SixC1-x:H)/i (Si:H)/n (SixC1-x:H)/Al (0<x<1) were produced by PE-CVD at low temperature. Junction properties, carrier transport and photogeneration are investigated from dark and illuminated current-voltage and capacitance-voltage characteristics. For the heterojunction cells Atypical J-V characteristics under different illumination conditions are observed leading to poor fill factors. High serial resistances around 106 Ω are also measured. These experimental results were used as a basis for the numerical simulation of the energy band diagram, and the electrical field distribution of the whole structures. Further comparison with the sensor performance gave satisfactory agreement.Results show that the conduction band offset is the most limiting parameter for the optimal collection of the photogenerated carriers. As the optical gap increases and the conductivity of the doped layers decreases, the transport mechanism changes from a drift to a diffusion-limited process.


Nature ◽  
1979 ◽  
Vol 278 (5701) ◽  
pp. 283-284 ◽  
Author(s):  
ROBERT W. HOLLEY ◽  
JULIA H. BALDWIN

Author(s):  
Peng Li ◽  
Assem Abolmaaty ◽  
Thomas Barek ◽  
Constantine Anagnostopoulos ◽  
Mohammad Faghri

Heterogeneous immunoassay (HI) has been recently used for on-chip biomolecule detection by many researchers due to its high specificity and precision. However, the protocols that have been published are too time-consuming. For HI based immunosensor to be attractive they should have short analysis times. In our work, a polydimethylsiloxane (PDMS) microfluidic device was fabricated to quantify a model analyte (bovine IgG) and used for optimizing the time required for each process. The results show that the incubation time of one single process could be reduced from typical 1 hour to 5 minutes without loss of performance. Our studies reveal that microfluidic devices are only effective in reducing incubation times for diffusion limited processes but not for interaction or adsorption limited process.


1993 ◽  
Vol 310 ◽  
Author(s):  
P-Y. Lesaicherre ◽  
H. Yamaguchi ◽  
T. Sakuma ◽  
Y. Miyasaka ◽  
M. Yoshida ◽  
...  

AbstractSrTiO3 thin films were prepared by ECR and thermal MOCVD. In thermal-CVD mode, Sr content and Ti content were at a maximum at 0.56 Torr. Results showed that SrO deposition is a surface reaction limited process between 500 and 650°C, whereas TiO2 deposition is surface reaction limited between 500 and 600 °C, and diffusion limited above 600 °C. At a low pressure of 8 mTorr, ECR oxygen plasma was found to help decompose Ti(i-OC3H7)4. In ECR-CVD mode, the deposition temperature could be lowered to 400 °C. TEM and SEM analyses showed that SrTiO3 thin films have a columnar structure. The size of the grains depends on film thickness, and their shape on film composition (Sr/Ti ). Films prepared by thermal-CVD had a lateral step coverage of 50 %. 40 nm SrTiO3 thin films (Sr/Ti = 1.0) prepared by thermal-CVD on Pt/TaOx/Si and annealed for 2 hours in O2 had a maximum dielectric constant of 139 (Cs = 31 fF/μm2 and teq = 1.1 nm) and a leakage current density of 6x10−8 A/cm2 at 1.0 V.


1989 ◽  
Vol 27 ◽  
pp. 29
Author(s):  
J.A.M. Berkers ◽  
P.M.P. van Bergen en Henegouwen ◽  
A.J. Verkleij ◽  
J. Boonstra

1983 ◽  
Vol 30 (6) ◽  
pp. 4059-4063 ◽  
Author(s):  
D. B. Brown ◽  
D. I. Ma ◽  
C. M. Dozier ◽  
M. C. Peckerar

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Akitsugu Kawabata ◽  
Takao Yamamoto ◽  
Hiroki Shinoda ◽  
Kazuto Yoshiba ◽  
Yoshiharu Toyama ◽  
...  

Plasma is regarded as a solution of precursor polymers specifically transformed to gel-forming polymers by a reaction with initiators. We developed a theory for the gel growth dynamics of plasma induced by contact with a source of gelators that are yielded by the initiation. In developing the theory, we combined the Ginzburg–Landau type dynamics with the gelator diffusion dynamics expressed by the moving boundary picture. The theory predicts the crossover of the rate-limiting process in the time course of the thickness of the gel layer X from the energy-limited process expressed by X∼t to the diffusion-limited process expressed by X∼t, where t is the time elapsed from when the plasma comes into contact with the source of gelators. A demonstration experiment was performed by placing a tissue factor coating plate as the initiator in plasma. Log–log plot of X vs. t showed a crossover as predicted by the theory, and the parameters characterizing plasma were determined.


1999 ◽  
Vol 13 (14n16) ◽  
pp. 2077-2084 ◽  
Author(s):  
Martin Hagenbüchle ◽  
Jing Liu

Structure formation and chain dynamics in a dilute, monodisperse ferrofluid emulsion under the influence of an external magnetic field have been studied using dynamic light scattering. Chain formation is found to be a diffusion-limited process that is well described by the Smoluchowski theory of irreversible aggregation. The characteristic time on which chain formation occurs depends strongly on volume fraction and on magnetic field strength. Rescaling the time leads to a universal behavior. Internal chain dynamics i.e.chain fluctuations are revealed by measurements of the apparent short-time diffusion coefficient as a function of the scattering angle. They show a strong dependence on the strength of the applied magnetic field.


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