Ellipsometry characterization for thin film silicon solar cells

Abstract

Spectroscopic ellipsometry was used to optimize p-layer deposition for silicon-based thin film solar cells. It is found that the p layer with a double-layer structure with increased boron-doping gives the highest open-circuit voltage (Voc) of 1.03 V for hydrogenated amorphous silicon (a-Si:H) solar cells. Together with atomic force microscopy and optical transmittance measurements, the cell performance - structure correlation was established. Furthermore, there appears to be the larger the p-layer band gap, the smaller the Voc for a-Si:H solar cells with H2-plasma treatment at i/p interface. It appears that the ellipsometry can be used as an inline diagnostic tool for the player deposition.