Front-surface recombination is one of the prominent loss mechanisms in some silicon solar cells, so understanding the passivation provided by fixed charges in dielectric layers is crucial to improving efficiency, particularly for devices with submicrometer and high-aspect-ratio surface features. The authors analyze field-effect passivation in textured and planar surfaces, through simulations and models accounting for the interaction between the opposing facets. The change in field-effect passivation upon texturing is significant for moderately large fixed-charge densities, yet negligible for very small or large densities.