Contribution of surface resonances to scanning tunneling microscopy images: (110) surfaces of III-V semiconductors

We show that the conventional dangling bond picture is insufficient to explain scanning tunneling microscopy (STM) images of III-V (110) semiconductor surfaces. Voltage-dependent STM images combined with nb initio electronic structure calculations give evidence that surface resonances fundamentally change the STM images of InP, GaP, and GaAs (110). The occupied dangling bond state dominates the images at negative voltages, but its counterpart, the empty dangling bond state, is only of relevance for small positive voltages. The empty state images are rather governed by empty resonances which lead to a 90 degrees rotation of the apparent rows.