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The spontaneous formation of electronic orders is a crucial element for understanding complex quantum states and engineering heterostructures in 2D materials. A novel 19$\sqrt {19} $ × 19$\sqrt {19} $ charge order in few-layer-thick 1T-TaTe2 transition metal dichalcogenide films grown by molecular beam epitaxy, which has not been realized, is report. The photoemission and scanning probe measurements demonstrate that monolayer 1T-TaTe2 exhibits a variety of metastable charge density wave orders, including the 19$\sqrt {19} $ × 19$\sqrt {19} $ superstructure, which can be selectively stabilized by controlling the post-growth annealing temperature. Moreover, it is found that only the 19$\sqrt {19} $ × 19$\sqrt {19} $ order persists in 1T-TaTe2 films thicker than a monolayer, up to 8 layers. The findings identify the previously unrealized novel electronic order in a much-studied transition metal dichalcogenide and provide a viable route to control it within the epitaxial growth process.

The spontaneous formation of electronic orders is a crucial element for understanding complex quantum states and engineering heterostructures in two-dimensional materials. We report a novel $\sqrt{19}\times\sqrt{19}$ charge order in few-layer thick 1T-TaTe$_2$ transition metal dichalcogenide films grown by molecular beam epitaxy, which has not been realized. Our photoemission and scanning probe measurements demonstrate that monolayer 1T-TaTe$_2$ exhibits a variety of metastable charge density wave orders, including the $\sqrt{19}\times\sqrt{19}$ superstructure, which can be selectively stabilized by controlling the post-growth annealing temperature. Moreover, we find that only the $\sqrt{19}\times\sqrt{19}$ order persists in 1T-TaTe$_2$ films thicker than a monolayer, up to 8 layers. Our findings identify the previously unrealized novel electronic order in a much-studied transition metal dichalcogenide and provide a viable route to control it within the epitaxial growth process.