Silicon-germanium layers

Physical Properties. Raman spectroscopy is an excellent tool for investigating stress and strain in many different materials (see Materlals reliability). Lattice strain distribution measurements in siUcon are a classic case. More recent examples of this include the characterization of thin films (56), and measurements of stress and relaxation in silicon—germanium layers (57). 

In 1981 an efficiency of 7.5% was obtained for a p-i-n structure (3.3 mm2) in which the p layer was a boron-doped silicon-carbon-hydrogen alloy (a-Si C H) (Tawada et al., 1981). A further improvement in conversion efficiency to 8.5% was obtained in 1982 with a stacked junction structure (9 mm2) that utilized an amorphous silicon-germanium-hydrogen alloy (a-Si Ge H) in the back junction of three stacked p-i-n junctions (Nakamura et al., 1982). More recently, an efficiency of 10.1% has been achieved in a p-i-n structure (1.2 cm2) utilizing p-type a-Si C H as a window layer (Catalano et al., 1982). 

S.C. Jain, Germanium-Silicon Strained Layers and Heterostructures, P.W. Hawkes (Ed.), Advances in Electronics and Electron Physics Series, Supplement 24, Academic Press, Boston, 1994. 

Volume 74 Silicon-Germanium Strained Layers and Heterostructures... 

We have studied alternating germanium-silicon-silicon oxide layers of 41 nm thickness grown on Si substrates by plasma enhanced chemically vapor deposition. The compositions of the grown films were determined by X-ray photoelectron spectroscopy. 

Another f pe of lattice this time of the homopolar class — b>iind jii normal al< icy ini ormetallir compounds is I ho tetrahedral cubic or adamantine lattice, which, when all I In atoms are carbon atoms, occurs in the diamond, as shown in Fig. 31. This lattice is also present in crystals of the other tetravalent elements, silicon, germanium and grey tin. In all of these elements the atoms have four outer-layer or valency electrons, each of which contributes to the formation of the four tetrahedral homopolar valency... 

Figure 6.2-23(a) shows the STM picture of an about 100 nm thick silicon layer that was electrodeposited at —1600 mV vs. Fc/Fc, probed under potential control with the in situ STM. Its surface is smooth on the nanometer scale and its topography is similar to that of a germanium layer of comparable thickness [79]. Figure 6.2-23(b)... 

Figure 8. The amplitude of oscillation versus square root of ion-cnergy dependence for two multilayer systems consisting of silicon and germanium layers 2 nm and 3 nm thick, respectively.

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