Strong-coupling theory of mobility collapse in GaN layers

Within the framework of strong-coupling theory we study the effect of highly negatively charged threading dislocations on the electron mobility collapse in n-GaN layers. An analytical expression is derived showing the way in which the electrically active dislocations establish the critical carrier concentration at which the collapse occurs. Results are presented suggesting that the experimental collapse data can be utilized for determining the characteristic magnitude of the statistical filling factor of dislocation related traps in the GaN bandgap.