Nature of dislocation-related luminescence in diamond, zinc-blende and wurtzite-type semiconductors

An investigation is performed of different models of dislocation-related photoluminescence (PL) in cubic semiconductors with diamond and zinc-blende lattices. It is concluded that the model of the dislocation exciton (DEX) and the DEX complexes with carriers in one-dimensional dislocation bands split-off from the volume bands by the dislocation strain field provides the best description of the observed properties of dislocation-related PL in Ge, Si, ZnSe, CdTe and ZnTe crystals. An extension of this concept on the case of wurtzite GaN allows to attribute the 364 nm PL-system to DEX and DEX complexes at c-axis screw dislocations. It was found that for a proper calculation of the carrier binding enegies at screw dislocations the topological interaction and the Berry geometrical phase should be taken into account. A calculation of the binding energies of DEX, hole and DEX+hole complex at the screw dislocation 35 meV, 65 meV and 7 meV in accord with experimental data.