Figure 5

Formation of an in-plane Schottky junction.

(a) Schematic of the energy band diagram of an H-terminated diamond from the surface into the bulk (z-axis as depicted in Fig. 3a). E_vac is the vacuum level, χ is the negative electron affinity, E_VBM and E_CBM is the valence band maximum and the conduction band minimum respectively, E_F is the Fermi level. H-C indicates the carbon-hydrogen bond at the surface and μ_a is the chemical potential of the aqueous wetting layer covering the diamond surface. 2-DHG is the two-dimensional p-type channel. Also shown are the charge transition levels NV^+/0 (1.2 eV above valence band maximum E_VBM²⁹) and NV^0/− (2.8 eV above valence band maximum E_VBM¹⁸) as well as the nitrogen donor level N (1.7 eV below conduction band minimum E_CBM³⁰). The green square indicates the region below the surface covered by nitrogen and both NV⁻ and NV⁰ centres generated by implantation (centre position is 7 nm below the surface with a standard deviation of 2.3 nm). (b) Schematic lateral band diagram of the Al/H-terminated diamond interface (x-axis as depicted in Fig. 3a). Φ_M is the work function of Al and w_SCR is the width of the lateral depletion region. The green lines at the NV charge transition levels indicate the NV-layer region. The energy level N of nitrogen, as shown in a), is not displayed for a better overview.