The atomic-scale defect origins of single-photon emission in atomically thin hexagonal boron nitride (h-BN) remains an unresolved challenge, which demands precise identification to achieve its potential applications in quantum technology. High-resolution atomic force microscopy (HR-AFM) provides a noninvasive approach for obtaining an atomic-scale understanding of point defects in h-BN. Here, we examine HR-AFM imaging of a representative point defect in h-BN: a carbon substitution of boron and an adjacent nitrogen vacancy (the ${\mathrm{C}}_{\mathrm{B}}{V}_{\mathrm{N}}$ defect). We address the electronic structure of this defect using first-principles simulations based on real space pseudopotentials within density functional theory. We also resolve a common problem with estimating lateral displacement in HR-AFM simulations using conventional approaches. These approaches often overestimate the lateral displacements at small tip-sample distances. We introduce a more accurate and computationally inexpensive iterative tilt correction method. Our analysis of the spin singlet (${}^1{A}_1$) and triplet (${}^3{B}_2$) states reveals the role of out-of-plane displacements and tip heights in imaging contrast. The HR-AFM image of the ${}^1{A}_1$ state exhibits bright spot shifts with tip height due to orbital tilts, whereas the planar ${}^3{B}_2$ state shows no such shift, which further highlights the electronic orbital contribution to AFM images. We demonstrate the ability of AFM simulations to quantify the relationship of the structural geometry and electronic state configuration of point defects in two-dimensional systems.

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• Color centers
• Point defects
• 2-dimensional systems
• Hexagonal boron nitride
• Density functional theory
• Noncontact atomic force microscopy
• Pseudopotentials