Employing angle-resolved photoemission spectroscopy (ARPES), we have investigated the electronic structures of Sb-substituted ${\mathrm{CeTe}}_2, {\mathrm{CeTe}}_{2-x}{\mathrm{Sb}}_x$ ($0\le x\le 0.5$), which exhibit charge density wave (CDW) transitions and enhanced thermoelectric (TE) properties and are also predicted to be topological material candidates. Two flat Ce $4f$ states are observed, one at approximately $-3.5\mathrm{eV}$ and the other at approximately $-0.8\mathrm{eV}$, which represent the $4f^1\to 4f^0$ transition and the Kondo-like $4f^1{\overline{L}}^0\to 4f^1{\overline{L}}^1$ transition (where $\overline{L}$ is a ligand hole) of trivalent ${\mathrm{Ce}}^{3+}$ ions, respectively. Two diamond-shaped inner and outer Fermi surfaces (FSs) are observed, which arise from the holelike band centered at $\mathrm{\Gamma }$ and from the folding of the two-dimensional Brillouin zone (BZ) into the three-dimensional (3D) BZ, respectively. The measured outer FSs demonstrate the non-negligible effect of the 3D electronic structures of ${\mathrm{CeTe}}_{2-x}{\mathrm{Sb}}_x$. The CDW-induced zigzag features are observed in the FS of $x=0$, but are not observed in the FSs of $x>0$, indicating the rapid suppression of the CDW state by the Sb substitution. This finding suggests that the increased resistivity at $x>0$, despite the weakened CDW formation, is possibly due to the disorder-induced localization by the Sb substitution, leading to the optimal TE properties at a specific $x$. The measured band structures of ${\mathrm{CeTe}}_{2-x}{\mathrm{Sb}}_x$ via ARPES exhibit very similar features for different $x$ values, except for the shift of the whole bands toward the Fermi level ($E_{\text{F}}$) with increasing $x$. This reflects the hole doping introduced by the Sb substitution, which is in good agreement with the calculated band structures. In the ARPES data of $x>0$, crossing bands are observed near the $X$ point at approximately $-1\mathrm{eV}$, which closely resemble Dirac points, suggesting the existence of topological electronic structures of ${\mathrm{CeTe}}_{2-x}{\mathrm{Sb}}_x$. Linear dichroism ARPES measurements on ${\mathrm{CeTe}}_{1.75}{\mathrm{Sb}}_{0.25}$ show that the $E_{\text{F}}$-crossing Te/Sb $p$ states along $X\text{−}\mathrm{\Gamma }\text{−}X$ and $M\text{−}\mathrm{\Gamma }\text{−}M$ have both in-plane and out-of-plane character, while those along $M\text{−}X\text{−}M$ have mainly in-plane character.

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• Charge density waves
• Fermi surface
• Two-dimensional electron system
• Photoemission spectroscopy