Germanium band structure

Mujica A and R J Needs 1993. First-principles Calculations of the Structural Properties, Stability, aind Band Structure of Complex Tetrahedral Phases of Germanium ST12 and BC8. Physical Review B48 17010-17017. 

Indirect transitions are much weaker thau direct trausitious, because the latter do uot require the participation of photons. However, many indirect-gap materials play an important role in technological applications, as is the case of silicon (band structure diagram iu Figure 4.7(a)) or germanium (baud structure diagram shown later, in Figure 4.11). Hereafter, we will deal with the spectral shape expected for both direct and indirect transitions. 

Figure 4.11 (a) The band structure of germanium (reproduced with permission from... 

An example of a one-dimensional superlattice structure is structure 1, which is an ordered copolymer. The skeleton is formed by silicon and germanium atoms. A unit cell is three times larger than that of a homopolymer. The band structure of this ordered copolymer changes to the zone-folded profile, which may result in a characteristic absorption spectrum. 

Draw the band structure expected for germanium doped with gallium. What sort of semiconductor would this be What type of charge carrier has been added ... 

Fig. 3.4. Band structure of germanium calculated from empirical pseudopotentials including s-o coupling as a function of the electron wave vector along selected directions of the reciprocal lattice. The s-o splitting Aso is the energy difference between Ts+ and IV. The light- and heavy-hole VBs are the IV1" to Le and IV1" to L4 +L5 bands, respectively. The energy reference is the VB maximum at the T point after [21]...

Fig. 3.19 The band structure of germanium, which is representative of that of the semiconductor families from groups IV, III, V and VI. (Reprinted with permission from Smith, R. A. Semiconductors. Cambridge University Press, 1978.)...

Figures 14.4 and 14.5 show calculated band structures of silicon and germanium, respectively. At the typical temperatures that will concern us (0-300 K), the only external action (that is, thermal excitation of electrons and holes, optical absorption edges) will occur dose to the highest point in the valence band and the lowest points in the conduction band.

Authors of [8] studied electronic and structural properties of silicon and germanium from first-principle models. Results allow one to describe qualitatively the band structure of sp-bonded metals and semiconductors by a few numbers the values of the spherical atomic-like potentials at a few lowest-reciprocal lattice vectors. By fitting to experimental data, some parameters could be used to describe a... 

A number of papers have appeared describing calculations of polymers based on bridged bithiophenes and their carbon, silicon, or germanium analogs (Chart 12.2). In 1995, Toussaint and Bredas [18] reported band structure calculations on polymer 10 with the VEH technique. The calculated bandgap... 

The principle of operation of this type of detector can be explained by the band structure of the electrons in the semiconductor crystal. The band gap of some semiconductor materials is very small, for germanium 0.66eV. A passage of radiation may inject sufficient energy into the structure to raise an electron from the valence band to the conduction band. By this an electron-hole pair is created. The expression hole has to be understood as the absence... 

Table 4.1-12 Band structures of Group IV semiconductors and IV-IV compounds, couL Germanium (Ge) (Fig. 4.1-27)...

Silicon and germanium are of great importance as intrinsic semicondnctors. Being unable to form double bonds, they can only crystallize in the cubic diamond structure (Figure 4a) with jp -hybridized atoms linked by four identical covalent bonds. Of particular interest is their band structure (Figure 5a). In diamond the C-C bond is so strong (C-C = 1.54 A) that, in spite of the band spreading, the... 

Figure 9.6 Band structure of (a) silicon and (b) germanium. Both are indirect semiconductors, that is, valence band maxima and conduction band minima are not aligned in reciprocal space. In Si, the minima of the...

G. Dresselhaus and M. S. Dresselhaus, Fourier expansion for the electronic band structure in silicon and germanium, Phys. Rev. 160, 649-79 (1967). 

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