Buffer layer thickness

TABLE 6 Variation of E2 with buffer layer thickness (with reference to a value of 568 cm 1) [31],... 

Figure 2.21. Dependence of NMSEF at surface of Si-CoSi2 BML substrate on angle of incidence as function of Si buffer layer thickness. Resuit obtained from bulk Si substrate without BML is also shown for comparison, (a) Verticai components for p-polarization ( z). (b) Lateral components for p- (Ex) and s-polarization (Ey). Here, v = 2900 cm" . Adapted, by permission, from Y. Kobayashi and T. Ogino, Appl. Surf. Sci. 100/101, 407 (1996), p. 410, Fig. 3. Copyright 1996 Elsevier Science B.V.

Figure 3.9. The p-polarized thermostimulated spectra of 0.6- xm ZnSe film on buried metai layer (BML) substrates Si-AI with Si buffer layer thickness (1)0, (2)2, and (3)3(jim. Points are experimental data solid curves are calculated. Experimental points are shifted downward for spectra 1 and 2 by 0.06 and for spectrum 3 by 0.13 (reduction of background radiation). Reprinted, by permission, from E. A. Vinogradov, Phys. Rep. 217, 159 (1992), p. 201, Fig. 26. Copyright 1992 Elsevier.

The present experimental results of the time smoothed velocity distribution are in good agreement with those reported by several authors (Reishman and Tiederman (13), Mizushina and Usui (10)), showing the increase both in laminar sublayer and buffer layer thickness. 

Al buffer layer thickness diffusion coefficient Pd over layer thickness Y film thickness... 

From our findings, it is clear that the use of a second buffer layer to screen out open-shell character is a vital convergence tool. The dual buffer approach also leads to more predictability in the quality of the D C results as the matrix cutoff is increased. In addition, it appears to be slightly more accurate than Yang s single buffer region approach with the equivalent total buffer layer thickness. 

Figure 2.34 CL linewidth of the ZnO near-band-edge emission as a function of LT buffer layer thickness and growth temperature. The linewidth decreases with increasing growth temperature and layer thickness of LT ZnO buffer. (After Ref [153].)...

Kato, H., Miyamoto, X, Sano, M. and Yao, T. (2004) Polarity control of ZnO on sapphire by the MgO buffer layer thickness Applied Physics Letters, 84,4562. 

As velocity continues to rise, the thicknesses of the laminar sublayer and buffer layers decrease, almost in inverse proportion to the velocity. The shear stress becomes almost proportional to the momentum flux (pk ) and is only a modest function of fluid viscosity. Heat and mass transfer (qv) to the wall, which formerly were limited by diffusion throughout the pipe, now are limited mostly by the thin layers at the wall. Both the heat- and mass-transfer rates are increased by the onset of turbulence and continue to rise almost in proportion to the velocity. 

For turbulent flow of a fluid past a solid, it has long been known that, in the immediate neighborhood of the surface, there exists a relatively quiet zone of fluid, commonly called the Him. As one approaches the wall from the body of the flowing fluid, the flow tends to become less turbulent and develops into laminar flow immediately adjacent to the wall. The film consists of that portion of the flow which is essentially in laminar motion (the laminar sublayer) and through which heat is transferred by molecular conduction. The resistance of the laminar layer to heat flow will vaiy according to its thickness and can range from 95 percent of the total resistance for some fluids to about I percent for other fluids (liquid metals). The turbulent core and the buffer layer between the laminar sublayer and turbulent core each offer a resistance to beat transfer which is a function of the turbulence and the thermal properties of the flowing fluid. The relative temperature difference across each of the layers is dependent upon their resistance to heat flow. 

I0-38Z ) is solved to give the temperature distribution from which the heat-transfer coefficient may be determined. The major difficulties in solving Eq. (5-38Z ) are in accurately defining the thickness of the various flow layers (laminar sublayer and buffer layer) and in obtaining a suitable relationship for prediction of the eddy diffusivities. For assistance in predicting eddy diffusivities, see Reichardt (NACA Tech. Memo 1408, 1957) and Strunk and Chao [Am. ln.st. Chem. Eng. J., 10, 269(1964)]. 

Taylor(4) and Prandtl(8 9) allowed for the existence of the laminar sub-layer but ignored the existence of the buffer layer in their treatment and assumed that the simple Reynolds analogy was applicable to the transfer of heal and momentum from the main stream to the edge of the laminar sub-layer of thickness <5. Transfer through the laminar sub-layer was then presumed to be attributable solely to molecular motion. 

A SiC buffer layer was grown on a silicon wafer at 1150-1300°C from one to 45 minutes using C3Hg and H2 as reactant gases. The thickness of the film increased gradually by diffusion of Si into the deposit until a thickness controlled by temperature and silicon etching was reached. 

Absorption in the p-layer can be reduced by using an a-SiC H alloy with a bandgap of about 2 eV [584]. Carbon profiling within the p-layer further improves the window properties [585]. An intentionally graded p-i interface (buffer layer) 10 nm in thickness enhances the spectral response in the blue [125, 494, 586], which can be attributed to a reduced interface recombination. 

The depth profiling technique used on samples with a barrier film before and after the addition of chloride to the buffering borate electrolyte showed no indication of either chloride penetration or significant reduction of the average oxide layer thickness.123 This, of course, does not rule out the possibility of the formation, by any of the mechanisms suggested above, of pinholes with radii much smaller than that of the ion-gun beam, through which the entire active dissolution could take place, or the possibility that the beam missed pits formed sporadically across the surface. If pinholes which are not visible were formed, the dissolution should proceed in them with extremely high true current densities. 

It has been reported that a thin interfacial oxide layer such as Si02, SiOvN, or Ti02 can improve device performance [39 11], Although the exact mechanism of such thin buffer layers is not clear, the enhanced performance may arise from the improved smoothness of the surface of ITO, which leads to more homogeneous adhesion of the HTL. In addition, the optimized thickness of the buffer layer also helps balance the device charges due to reduced hole injection. 

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