Germanium (Ge) substrates are used for the growth of III-V optoelectronic devices such as solar cells. However, Ge is a critical raw material due to its limited availability. Furthermore, Ge substrate accounts for about 30-40 percent of the total costs of a triple junction solar cell. In this work III-V samples and solar cells were grown on Ge substrates with different technologies (techs). Three different techs were investigated: 1) using Ge substrates with porous layers to grow III-V materials, in which the porous layer is removed so that the substrate can be reused; 2) using thinner substrates and with fewer surface finishing processes, which makes it rougher compared to commercial substrates; 3) replacing the Ge substrate with alternative substrates that comprise other elements, such as a Si substrate where a metamorphic SiGe buffer is deposited, in which the lattice parameter is gradually adjusted until it reaches Si0.1 Ge0.9. The substrates used are not as perfect as commercial Ge substrates and can generate defects in the subsequent III-V layers. To investigate the influence of these substrates on III-V layers, double heterostructures (DH) of AlGaInAs/GaInAs were grown on the substrates of techs 1 and 2 and DH of AlGaAs/GaAs on the substrates of tech 3. Their properties were evaluated with AFM to obtain the root mean square roughness and possible surface defects, cathodoluminescence to estimate the density of defects in the structure and Electron Channeling Contrast Imaging to identify the types of defects found with CL. Furthermore, for samples grown on tech 1 substrates, the compositions and thicknesses were evaluated by XRD, and with time-resolved photoluminescence, the lifetime of the electrons was evaluated. Triple junction solar cells were also grown on techs 2 and 3 substrates, which were processed and characterized by I-V and EQE curves. The results obtained with all tecs lead to an optimistic perspective for a future with cheaper solar cells that use less Ge.