with Room Temperature Broad Photoluminescence*

2D oxide semiconductors with large band-gap have gained significant attention for the development of high-performance and energy-efficient electronics. Recently, there have been few theoretical investigations on β-phase TeO₂. Moreover, only a handful of experimental work has been demonstrated, which shows β-TeO₂ transistors exhibit a high-mobility p-type semiconductor with hole mobility up to ~232 cm² V^-1 s^-1 at room temperature and a band gap in the range of 3.2 to 3.7 for bulk to monolayer, respectively. Here, we report a reliable and well-controlled method to form layered β-TeO₂ large band gap semiconductor obtained via deterministic laser-induced oxidation of exfoliated β-Te. We show Raman signatures of β-TeO₂ readily after laser oxidation. This 2D wide bandgap semiconductor possesses a broad photoluminescence (PL) spectrum with multiple peaks covering the range 1.76 eV to 2.08 eV. This optical emission indicates a strong exciton binding energy which is estimated to reach ~1.54 eV to 1.6 eV. This work highlights important methods to obtain 2D oxide semiconductor with large band gap for electronic and photonic applications.