We have applied real time spectroellipsometry (RTSE) to study the growth of microcrystalline silicon n- and p-layers [μc-Si:H:(P,B)] incorporated into amorphous silicon (a-Si:H) p-i-n and n-i-p solar cells, respectively. In previous research, we have applied RTSE to characterize a-Si:H solar cells having only amorphous component layers. The μc-Si:H(P,B) component layers, however, pose a more difficult RTSE analysis problem for two reasons. First, the near-surface of the underlying i-layer is modified in the μc-Si:H:(P,B) growth process, and second, the microstructural evolution near the i/(n,p) interfaces is very complicated. From RTSE spectra (1.5 < hv < 4 eV) collected every ∼4–15 s during growth, we have extracted the time evolution of the μc-Si:H:(P,B) layer microstructure, thicknesses, and optical properties along with the modifications that the near-surface i-layer properties undergo in the formation of the i/(n,p) interfaces. We suggest that the beneficial optical properties of the microcrystalline layers may be due to size effects in the crystallites that make up the films.