%0 Journal Article
%A Freter, Lars
%A Lymperakis, Liverios
%A Schnedler, Michael
%A Eisele, Holger
%A Jin, Lei
%A Liu, Jianxun
%A Sun, Qian
%A Dunin-Borkowski, Rafal E.
%A Ebert, Philipp
%T Composition dependence of intrinsic surface states and Fermi-level pinning at ternary Al x Ga1− x N m -plane surfaces
%J Journal of vacuum science & technology / A
%V 42
%N 2
%@ 0734-2101
%C New York, NY
%I Inst.
%M FZJ-2024-04929
%P 023202
%D 2024
%X Growth on nonpolar group III-nitride semiconductor surfaces has been suggested to be a remedy for avoiding detrimental polarization effects. However, the presence of intrinsic surface states within the fundamental bandgap at nonpolar surfaces leads to a Fermi-level pinning during growth, affecting the incorporation of dopants and impurities. This is further complicated by the use of ternary, e.g., Al(x)Ga(1-x)N layers in device structures. In order to quantify the Fermi-level pinning on ternary group III nitride nonpolar growth surface, the energy position of the group III-derived empty dangling bond surface state at nonpolar Al(x)Ga(1-x)N (10-10) surfaces is determined as a function of the Al concentration using cross-sectional scanning tunneling microscopy and spectroscopy. The measurements show that the minimum energy of the empty dangling bond state shifts linearly toward midgap for increasing Al concentration with a slope of  ~5 meV/%. These experimental findings are supported by complementary density functional theory calculations.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001153140000005
%R 10.1116/6.0003225
%U https://juser.fz-juelich.de/record/1029011