Raman signatures of pressure induced electronic topological and structural transitions in Bi2Te3

► We investigated the ETT and structural transitions at ∼3.6 GPa and at ∼8 GPa. ► A new dispersionless Raman mode at ∼3.6 GPa coinciding with the onset of the ETT. ► A structural transition to monoclinic phase is evidenced at ∼8 GPa. ► The metallization process is gradual completing at ∼14 GPa.