On the electronic states at dislocations in germanium

Abstract

Dislocation states in germanium are investigated in a series of deformed specimens with doping concentrations between 1012 acceptors and 1015 donors per cm3. The Fermi energy, EF, and the occupation ratio, f, of the dislocation levels are determined from Hall effect measurements. Possible errors of f are carefully discussed. From this discussion experimental conditions are obtained under which a reliable comparison of the results with theoretical models is possible. For p‐type as well as for n‐type material the results are found to be in quantitative agreement with the model of a partly filled dislocation band. An explanation is given for the discrepancies between previous results of different authors.

Influence of defects and interface on radiative transition of Ge

“…The bulk Ge is ϳ15 times the integrated intensity of PL of the Ge-on-Si sample indicating that more defects 11,12 in the Ge-on-Si sample increase the nonradiative recombination rate due to Shockley-Read-Hall recombination. 13 Figure 3 shows the models of the indirect band transition in the ͑a͒ ideal bulk Ge ͑without defects͒ and ͑b͒ Ge-on-Si ͑with de-fects͒.…”

Mechanisms Determining the Critical Current in Hard Superconductors

“…13, p. 11) which on combination with Eq. (14) gives the central result of this analysis: pinning force density F p which yields the same square law dependence on fp that Labusch found for individual strong pinning points [Eq. (11)].…”

The Structure And Electrical Properties Of Dislocations In Semiconductors

“…Electrical measurements of deformed crystals have often been interpreted in terms of this model (e.g. Labusch & Schettler, 1972;Labusch & Schroter, 1975;Wagner & Haasen, 1975). Similarly, it can be shown that edge dislocations on the 'shuffle' planes have two dangling bonds per repeat period, but for electrons/holes moving along the dislocation cores there is no first order Bragg reflection so that there is no energy gap at the first Brillouin zone boundary.…”

“…At the present time there is little agreement on the energy levels of defects states in dislocated crystals, let alone their identification with particular core configurations. For Ge, Hall conductivity and photoconductivity measurements on compressed specimens have been interpreted in terms of a half full band at E, + 0.09 eV in the neutral state (Labusch & Schettler, 1972;Labusch & Schroter, 1975;Merge1 & Labusch, 1977), and Hall conductivity measurements on twisted specimens have provided evidence for an additional full donor band at E, + 0.035 eV, and an empty acceptor band at Ev+0.59 eV in the neutral state (Wagner & Haasen, 1975). The half full band found in compressed specimens has been attributed to dangling bonds in 60" and edge dislocations, the bands in twisted specimens to the states arising from shear and dilational strain field around screws (Wagner & Haasen, 1975;Celli et al, 1962).…”