Electronic properties of dislocations in GaN investigated by scanning tunneling microscopy

We investigated the type, spatial distribution, line direction, and electronic properties of dislocations in n-type GaN by scanning tunneling microscopy. We found uncharged perfect dislocations with a/3{112¯0} Burgers vectors and negatively charged Shockley partial dislocations with a/3{11¯00} Burgers vectors interconnected by a negatively charged stacking fault. The charges are traced to different charge transfer levels associated with the particular core structure.