The dislocation-related photoluminescence of n-Ge single crystals with a quasi-equilibrium structure of 60° dislocations was investigated at 4.2K. It was shown that the dislocation-related photoluminescence spectra were described by a set involving from 8 to 13 Gaussian lines with a width of less than 15meV. With due regard for the data available in the literature, the Gaussian lines with maxima at energies in the range 0.47 < Em ≤ 0.55eV were attributed to the emission of 90° Shockley partial dislocations involved in quasi-equilibrium segments of 60° dislocations with different values of the stacking fault width, Δ (Δ = Δ0, Δ < Δ0, and Δ > Δ0). It was revealed that the d8 line at an energy of Em = 0.513eV, which corresponded to the emission of straight segments with the equilibrium stacking fault width, Δ0, predominated in the photoluminescence spectra only at dislocation densities ND < 106/cm2. As the dislocation density, ND increased, the intensity of the d8 line decreased with the d7 line (Em ≈ 0.507eV) initially and the d7 and d6 lines (Em ≈ 0.501eV) then becoming predominant in the photoluminescence spectrum. The d7 and d6 lines were attributed to the emission of segments with stacking-fault widths, Δ < Δ0. Possible factors responsible for the formation of stacking faults with particular widths Δ ≠ Δ0 for quasi-equilibrium dislocations were considered.

Photoluminescence in Germanium with a Quasi-Equilibrium Dislocation Structure. S.A.Shevchenko, A.N.Tereshchenko: Physics of the Solid State, 2007, 49[1], 28-33