Capacitance–voltage characterization of silicon oxide and silicon nitride coatings as passivation layers for crystalline silicon solar cells and investigation of their stability against x-radiation

In this work capacitance–voltage measurements of three different dielectric layers, thermal silicon oxide, plasma enhanced chemical vapor deposited (PECVD) silicon oxide, and PECVD silicon nitride, on p-type silicon have been performed in order to obtain characteristics as the energy distribution of the interface trap density and the density of fixed charges. Spatially resolved capacitance–voltage, ellipsometry and lifetime measurements revealed the homogeneity of layer and passivation properties and their interrelation. Additionally lifetime measurements were used to evaluate x-radiation induced defects emerged during electron beam evaporation for sample metallization.