  X-ray photoelectron spectroscopy (XPS) is an important characterization tool
in the pursuit of controllable fluorination of two-dimensional hexagonal boron
nitride ($h$-BN). However, there is a lack of clear spectral interpretation and
seemingly conflicting measurements exist. To discern the structure-spectroscopy
relation, we performed a comprehensive first-principles study on the boron 1s
edge XPS of fluorinated $h$-BN (F-BN) nanosheets. By gradually introducing 1--6
fluorine atoms into different boron or nitrogen sites, we created various F-BN
structures with doping ratios ranging from 1-6\%. Our calculations reveal that
fluorines landed at boron or nitrogen sites exert competitive effects on the
B1s binding energies (BEs), leading to red or blue shifts in different
measurements. Our calculations affirmed the hypothesis that fluorination
affects 1s BEs of all borons in the $\pi$-conjugated system, undermining the
transferability from $h$-BN to F-BN. Additionally, we observe that BE generally
increases with higher fluorine concentration when both borons and nitrogens are
non-exclusively fluorinated. These findings provide critical insights into how
fluorination affects boron's 1s BEs, contributing to a better understanding of
fluorination functionalization processes in $h$-BN and its potential
applications in materials science.
