Research

PLASMA ENHANCED CHEMICAL VAPOR DEPOSITION (PECVD) FOR SOLAR CELLS

Introduction

Amorphous hydrogenated silicon films with embedded nanocrystallites (nc-Si) hold great promise for solar cells, flexible electronics, displays, and other applications. A novel reactor is under development to grow nanocrystalline silicon (nc-Si) films by plasma enhanced chemical vapor deposition (PECVD). The layer-by-layer control of alternating deposition and crystallization reactions, along with the wide parameter space possible with this unique reactor, could produce nanocrystalline films with superior properties for solar cells and other applications. Surface and plasma diagnostics will monitor the nanocrystallization and gaseous product formation processes. Transmission electron microscopy and laser Raman scattering will yield the fraction of crystalline and amorphous material in the films, while spectroscopic ellipsometry and IR absorption will be used to further characterize the material. Optical emission spectroscopy and mass spectrometry will be employed to monitor gaseous reactants and byproducts. Coupled plasma and neutral gas flow simulations will aid the experimental design and interpretation of measurements. The combination of experiments and simulations will also help relate experimental conditions of high quality nc-Si film growth to spatiotemporal plasma structure and key species densities.

Selected Publications

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