  The dosing of layered materials with alkali metals has become a commonly used
strategy in ARPES experiments. However, precisely what occurs under such
conditions, both structurally and electronically, has remained a matter of
debate. Here we perform a systematic study of 1T-HfTe$_2$, a prototypical
semimetal of the transition metal dichalcogenide family. By utilizing photon
energy-dependent angle-resolved photoemission spectroscopy (ARPES), we have
investigated the electronic structure of this material as a function of
Potassium (K) deposition. From the k$_z$ maps, we observe the appearance of 2D
dispersive bands after electron dosing, with an increasing sharpness of the
bands, consistent with the wavefunction confinement at the topmost layer. In
our highest-dosing cases, a monolayer-like electronic structure emerges,
presumably as a result of intercalation of the alkali metal. Here, by bringing
the topmost valence band below $E_F$, we can directly measure a band overlap of
$\sim$ 0.2 eV. However, 3D bulk-like states still contribute to the spectra
even after considerable dosing. Our work provides a reference point for the
increasingly popular studies of the alkali metal dosing of semimetals using
ARPES.
