The crystallization of high-rate electron beam evaporated amorphous silicon on ZnO:Al-coated glass and SiN-coated glass was investigated by applying ex-situ optical microscopy and isothermal annealing. The nucleation process in solar cell structures consisting of n+-Si(PECVD)/p-Si/p +-Si layers was analyzed and subsequently compared to the phase transition in p-Si and n+-Si(PECVD)/p-Si on SiN and ZnO:Al-coated glass. With a high steady-state nucleation rate and a low activation energy (EIss = 2.7 eV), the nucleation process of Si on ZnO:Al has shown to differ significantly from nucleation on SiN (EIss = 4.5 eV) in the investigated temperature regime of 560 ° C to 600 ° C. The experiments revealed that the n+-Si(PECVD) layer did not serve as a nucleation layer and did not influence the nucleation of p-Si on SiN. On ZnO:Al, however, the nucleation rate of n+-Si(PECVD)/p-Si was found to be smaller than the nucleation rate of a single p-Si layer. While the p+-Si promotes the nucleation on SiN, it did not affect the nucleation process of Si on ZnO:Al. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.