Solar cell (SC) cost reduction remains the main problem in PV development. Selfformation technology implementation is one of the ways to decrease this cost. It is known planar object.s evolution approximation by 8-dimensional topological space, containing object geometry, set of parameters, medium set and matrix of interaction. There we can have some different cases: external formation, self-formation, development and reproduction. However in case of self-formation, these attributes are not sufficient, because the different sequences of media can be created from the same set of medium. In external formation all structured and chaotic media are brought from outside and technological graph is created from recurrent parts. There we see an object interaction with different structured media, which structures are transferred to evolving object, and recurrent sequence of chaotic media (deposition, exposure, development, etching, diffusion and oxidizing). Initial technological object, interaction matrix and set of interactions are not sufficient to unambiguous technological process describing in self-formation case as well. Some technological graphs may be valid to one interaction matrix and result different final object. Medium there are changed from outside but the initial object changes as the result of interaction with medium. In optimal case one structured medium (for initial object formation) and the sequence of chaotic media are necessary to manufacture the solar cell from the silicon wafer. The approach of technological graph to solar cell technology is presented. Graphs of external formation and self-formation of solar cell are compared.