The optimization of the structure of the Ge thermophotovoltaic (TPV) cell was perfected through the study of energy band diagrams. Simulations were used to identify SiGe for passivation of the Ge emitter, and Ge(N+) as the rear passivating layer. The epitaxial structure of the Ge TPV cell, with a total thickness around 15 μm, was grown by MOCVD with excellent morphological qualities. The prototypes of the new innovative TPV cells were built by implementing new post growth process steps. The presence of SiGe in the new device structure caused difficulties regarding the adhesion of the back and front contact metallizations. Furthermore, the TAIKO process, successfully used in the Line of Activity (LA) 1.07 for thinning the substrates, showed some problems in the creation of this specific structure. Therefore it was not possible to realize the innovative TPV device with dual-functional optical filter on thin substrates. Two different simplified prototypes of innovative TPV devices were realized, which were then characterized through voltage-current measurements, using the blackbody source developed in LA 1.11 and the solar simulator. In the first prototype, featuring two front-back terminals, the I-V curves showed an anomalous “S” shape due to the imperfect ohmicity of the contact between the metal and the SiGe. In the second prototype, with two terminals on the front, resistance phenomena attributed to the simplified geometry of the device were observed. The innovative TPV devices showed a short-circuit current density value 2.6 times lower than that of commonly used TPV devices. Bearing in mind the difficulty in creating frontal contacts using wet etching, the results obtained, though positive, are to be considered a starting point which can certainly be improved using manufacturing technologies more suited to the innovative structure of the proposed TPV device. This activity therefore confirms the potential of obtaining a type of TPV cell for application in thermophotovoltaic microgeneration, which is more economical and efficient than the usual ones.