Study of polycrystalline silicon layers for photovoltaic applications

Abstract

This thesis concerns the study of silicon single junction solar cells deposited by plasma- enhanced chemical vapor deposition on the industrial Fe-Ni alloy substrate. This ap- proach is promising for fabrication of low-cost high-efficiency solar cells. The main aim is to characterize the intrinsic polycrystalline silicon layer which is crucial for light absorp- tion and solar cell efficiency. The real-time ellipsometric data obtained during material deposition in reactor are used to model the composition of grown material. Based on the designed model, the evolution of material crystallinity as well as the thickness and compo- sition of the surface roughness layer are established and average growth rate is estimated. The transmission electron microscopy is used to obtain the images of material structure. Finally, the key performance characteristics of studied solar cells are determined based on current-voltage characteristic and external quantum efficiency measurement.