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Real time spectroscopic ellipsometry has been applied to develop deposition phase diagrams for p-type hydrogenated silicon (Si:H) films prepared at low temperature (200 °C) by rf plasma-enhanced chemical vapor deposition using gas mixtures of SiH4, H2, and BF3. These diagrams depict the regimes of accumulated thickness and H2-dilution ratio R=[H2]/[SiH4] within which p-type amorphous Si:H [a-Si:H], mixed-phase Si:H [(a + μc)-Si:H], and single-phase microcrystalline Si:H [μc-Si:H] films are obtained in depositions on R=0 a-Si:H surfaces. The performance of n–i–p solar cells incorporating p-layers deposited under the same conditions as those used in the phase diagram development has been correlated with …

Three different surface microstructural transitions have been identified versus accumulated bulk layer thickness db during the growth of hydrogenated silicon (Si:H) films by plasma enhanced chemical vapor deposition (PECVD): (i) an amorphous growth regime roughening transition, (ii) an amorphous-to-(mixed-phase amorphous + microcrystalline) roughening transition, and (iii) a (mixed-phase)-to-(single-phase) microcrystalline smoothening transition. These transitions are observed using real time spectroscopic ellipsometry, and the results can be summarized succinctly using deposition phase diagrams wherein the transition thicknesses of interest are plotted versus the H2-dilution ratio R=[H2]/[SiH4]. For Si:H p–i–n solar cells, a greater understanding of processing-property relations and optimization procedures is possible …