摘要
Scanning tunneling microscopy (STM) was used to study the (110) cross‐sectionalsurfaces of molecular‐beam epitaxially grown III–V homo‐ and heterostructures,which include GaAs multiple p–n junctions, (InGa)As/GaAs strained‐layermultiple quantum wells, and (AlGa)As/GaAs heterojunctions. Both doping and compositional effects can be resolved by the topographic contrasts of constant‐current STM images. The samples were prepared by either cleaving in ultrahigh vacuum or cleaving ex situ followed by sulfide [(NH4)2S] passivation. Sulfide passivated samples have been found to be advantageous for the measurements of scanning tunneling spectroscopy.