Betrachtung der Kristallinitätsentwicklung in mikrokristallinem Dünnschicht-Siliziummit in-situ Raman-Spektroskopie

In this thesis, the correlation between the preparation of hydrogenerated microcrystalline silicon ($\mu$c-Si:H), the evolution of the crystalline volume fraction and the performance of thin-film silicon solar cells is investigated. Microcrystalline silicon is a heterogeneous mixed phase material, composed of crystalline and amorphous domains, grain boundaries and voids.For the fabrication of $\mu$c-Si:H plasma enhanced chemical vapor deposition (PECVD) is acommonly used technique. The crystalline volume fraction of $\mu$c-Si:H is of fundamental importance for the material quality and can be estimated by the Raman crystallinity. Most favorable material properties for the application as absorber layer in solar cells are detected close to the transition to hydrogenated amorphous silicon (a-Si:H) and for Raman crystallinities between 60 % and 70 %. To characterize the evolution of the Raman crystallinity in growth direction, an institution’s internal setup was used that enables the monitoring of Raman spectra during the silicon deposition with high depth resolution of < 10 nm. The already existing setup was developed further in this thesis: A coating protection was designed to reduce the coating rate on the Raman optics in the PECVD-reactor by one order of magnitude. Moreover, the optical materials were optimized for the detection of the Raman spectra of $\mu$c-Si:H and the data analysis was automatized. [...