The main focus of this thesis are the 3D topological insulators bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3), which have been known for several decades as narrow band gap insulators (about 150 meV) and for their thermoelectric properties. Since they were found to be topological insulators, scientific interest in the search for topologically protected surface states has increased and the electronic properties of these states have been studied widely using angle-resolved photoemission spectroscopy. These measurements confirmed the presence of metallic states within the band gap with almost linear dispersion relations and a Dirac point. Also, surface magneto-electric properties measured by scanning tunnelling microscopy have shown that the protected surface states in Sb2Te3 thin films are less sensitive to intrinsic defects. This promises charge carriers with a high mobility at the surface of these materials. However, all properties mentioned above are solely restricted to the topological protected surface states and thus require the bulk to be insulating in order to observe these effects in electrical transport. Otherwise they will be masked by the bulk conductance. This has proven to be a difficult task, since all the binary materials tend to be intrinsically doped due to the formation of crystal defects during growth. Therefore, the effort has concentrated on controlling the sample fabrication, carrier compensation doping, or alloying of intrinsic chalcogenide materials, in order to shift the Fermi level into the energy bandgap and closer to the Dirac zero gap point of the surface energy spectra. In this work, we analyze thin films grown by molecular beam epitaxy on Si(111)-substrates. First, the binary materials are introduced in terms of crystal structure, growth parameters, electronic structure and elemental distribution via investigations done by transmission electron spectroscopy, angle-resolved photoemission spectroscopy and atom probe tomography. This illustrates the intrinsic doping of Bi2Te3 and Sb2Te3 and the presence of different crystal domains due to the growth mechanism of the layered films. We also compare films grown on 100 mm wafers with samples of selectively grown films on pre-patterned substrates. These samples are precursors to the nanostructures that will be discussed in the last chapter. Next, two different approaches to engineer the Fermi level are presented. Films of (Bi{1-x}Sb{x})}2Te3 with different compositions x, measured by Raman spectroscopy, and heterostructures with increasing Sb2Te3 thicknesses on top of a Bi2Te3 layer with fixed height are investigated. Both reveal a transition between opposite types of doping in angle-resolved photoemission spectroscopy. After this, the methods of sample preparation are presented, including two different approaches for preparing nanostructures using selective area growth. The last chapter is divided into two main parts. The first part begins by summarizing our measurements and characterizations of Bi2Te3 and Sb2Te3 films with regards to their transport properties like doping, mobility and parameters of phase coherent transport. We also extract these parameters from (Bi{1-x}Sb{x})}2Te3 with different compositions and the Sb2Te3/Bi2Te3 heterostructures with varying layer thicknesses. We search for hints of topologically protected surface states in field dependent measurements at low temperatures and analyse the influence of electrical gates. The second part contains the results from measurements on Bi2Te3 nanostructures. We present nanoribbons prepared by the two different approaches for selective area growth, show their respective idiosyncrasies and compare transport parameters obtained from wider ribbons with those from the films in the previous part. Next, nanodots are investigated to check for transport anisotropies with regards to the crystalorientation. In both cases we also analyse the corresponding magnetoresistance measurements for effects of phase coherent transport and influences of the surface states. Finally, we demonstrate our first attempts on suspended films of Bi2Te3
