ABSTRACT
The sputtering method has important advantages in terms of larger-area applicability, low environment load, low cost, and safety. Therefore, it is suitable for application to solar cell (SC) fabrications. In this chapter, a novel Si/SiGe–Ge multijunction SC structure will be proposed, and sputtering epitaxy (SE) of Si and Ge on Si(100) substrate at under 360◦C for application to SCs will be demonstrated. Film characteristics, which were evaluated by transmission electron microscope (TEM), Raman scattering, Hall measurement, and so on, were shown in relation to temperature of post-deposition forming gas annealing (FGA). The conductivity of SE films were controlled by the cosputtering of acceptor or donor impurities with Si or Ge and were controlled in the order of 1016 to 1020 cm−3 nip-Si thin-film SC on Si(100) substrate and wafer nip-Ge thin-film SC on Ge(100) substrate were fabricated and analyzed for the first time.
