Germanium, ground state energy

For B in silicon and Al in germanium, the parameters A and / (see text) of the short-range potential are obtained from the experimental ground state energies. The last column gives the non-variational values of [36] for a point-centre acceptor a Given as ir7 + in [36]... 

Earliest studies concentrated on the H3M+ cations (M = C, Si, Ge, Sn, Pb) with planar Dsh symmetry. However, CASSCF and MRSDCI calculations of the ground state geometries and energies of various germanium hydrides and hydride cations found a pyramidal C3V ground state structure for the H3Ge+ cation 4.6 kcalmol (CASSCF) or 6 kcalmol (MRSDCI) below the planar D311 structure, and predicted a rapid umbrella inversion at room temperature. 

Since the first energy level calculations of the EM centres in silicon and germanium [28,34], many calculations have been undertaken to explain quantitatively the absorption and photoluminescence (PL) spectra associated with these centres in many semiconductors. The first part of this chapter is devoted to the presentation of the energy level calculations of EM donors and it is followed by the results of the calculations for EM acceptors. The modification to EMA, which is independent of the chemical nature of the centres, is also discussed. The chapter concludes with results of calculations of the oscillator strength (OS) for transitions between the ground states and the acceptor or donor states. 

Fig. 6.40. Pseudo-donor absorption spectrum in the far IR of excitons bound to Be0 and Zn° in germanium. The transition labels, at the top, are those of the shallow donor states associated with the excited states of the pseudo-donors. The components of the 2P line in Ge Be and Ge Zn show thermalization between 1.6 and 4.2 K, indicating splitting of the BE ground states. The energy scales have been shifted so as to align the 3P transitions of the Ge Be0 and Ge Zn° spectra. The FE feature in (a) and (b) is due to the FE absorption. Reproduced from [247]. Copyright 1987, with permission from Elsevier...

In germanium samples diffused with TMs or Cu-contaminated, SAi-like acceptor spectra were also observed [23,71], These acceptors are also characterized by a split ground state. The ionization energies of their ground and thermalized states are given below, with SAi for comparison ... 

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