Real time optics of p-type silicon deposition on specular and textured ZnO surfaces

Using insights from real time spectroscopic ellipsometry (RTSE) studies, we have developed an evolutionary phase diagram that describes rf plasma-enhanced chemical vapor deposition (PECVD) of p-type silicon (Si:H) films on specular zinc-oxide (ZnO)-coated glass substrates at 200°C. Using this diagram, optimized conditions have been identified for the deposition of 200-Å-thick, single-phase, p-type microcrystalline Si:H (μc-Si:H) on glass/(specular ZnO). These conditions have also been applied for p-layer incorporation into an amorphous Si:H (a-Si:H)-based p-i-n solar cell fabricated on a glass/(textured SnO₂)/ZnO bilayer substrate. We find that the microstructural evolution, phase, and optical properties are similar for the optimized 200-Å-thick μc-Si:H p-layers prepared on the specular and textured ZnO. These results demonstrate that the presence of macroscopic substrate texturing does not necessitate process reoptimization for μc-Si:H film growth on ZnO