The electron affinity and surface states are of utmost importance for designing the potential landscape within (heterojunction) nanowires and hence for tuning conductivity and carrier lifetimes. Therefore, we determined for stoichiometric nonpolar $\mathrm{GaN}\left(10\overline{1}0\right)$ $m$-plane facets, i.e., the dominating sidewalls of GaN nanowires, the electron affinity to $4.06\pm 0.07\mathrm{eV}$ and the energy of the empty Ga-derived surface state in the band gap to $0.99\pm 0.08\mathrm{eV}$ below the conduction band minimum using scanning tunneling spectroscopy. These values imply that the potential landscape within GaN nanowires is defined by a surface state-induced Fermi-level pinning, creating an upward band bending at the sidewall facets, which provides an electronic passivation.

中文翻译：

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GaNm平面刻面的电子亲和力和表面状态：对电子自钝化的影响

电子亲和力和表面态对于设计（异质结）纳米线内的势态图以及因此调节电导率和载流子寿命至关重要。因此，我们确定了化学计量的非极性$\mathrm{氮化镓}（10\overline{\mathrm{1个}}0）$ $米$平面的小平面，即GaN纳米线的主要侧壁，对电子的亲和力 $4.06\pm 0.07\mathrm{电子伏特}$ 以及带隙中空Ga衍生的表面态的能量 $0.99\pm 0.08\mathrm{电子伏特}$扫描隧穿光谱法可将导通带降至最小导带以下。这些值表明，GaN纳米线内的潜在势态由表面状态诱导的费米能级钉扎定义，从而在侧壁小平面上产生向上的带弯曲，从而提供了电子钝化作用。