The 3D topological insulator (TI) materials Bi2Se3 and Bi2Te3 belong to a new class of materials that are characterized by insulating bulk properties but host quasi-relativistic states at their surface. These topological surface states form as a consequence of the differing topology of the underlying Hamiltonian of the material and air and have been shown to be very robust at ambient conditions as long as the topological character of the bulk is unchanged. In addition, the strong spin-momentum locking that is present in Bi2Se3 and Bi2Te3 leads to helical spin-polarization and protects the surface states against backscattering and enables dissipationless transport. Since their discovery these novel quantum states have lead to a vast interest in the condensed matter community for the realization of applications in spintronics, quantum computing and low-resistance materials at room temperature. This work presents studies on Bi2Se3 and Bi2Te3 in the form of 2D nanoflakes, which greatly reduces bulk contribution and enhances the topological surface properties. By the use of Raman spectroscopy this work investigates the interaction of the crystal lattice with the electronic degrees of freedom in the ultrathin limit. Hereby, the investigation of the phonon’s frequency and line shape is used to identify significant electron-phonon interactions. By investigating the 2D nanoflakes’ Raman response under the influence of different external parameters like low temperatures, strong magnetic fields, and the interface to a gold substrate, the changes in electron-phonon coupling are identified. These are used to deduct information on the nature and manipulation of the topological band structure in the ultrathin flakes. In detail, high resolution temperature dependent Raman measurements in the range between 300K to 3K reveal for Bi2Se3 additional phonon self-energy corrections at low temperatures caused by interactions with an electronic susceptibility in the energy range of the phonons. This electronic susceptibility can be ...