The present invention provides strategies for improving the adhesion among two or more of transparent conducting oxides, electrically conductive grid materials, and dielectric barrier layers. As a consequence, these strategies are particularly useful in the fabrication of heterojunction photovoltaic devices such as chalcogenide-based solar cells. When the barrier is formed and then the grid is applied to vias in the barrier, the structure has improved moisture barrier resistance as compared to where the barrier is formed over or around the grid. Adhesion is improved to such a degree that grid materials and dielectric barrier materials can cooperate to provide a hermetic seal over devices to protect against damage induced by environmental conditions, including damage due to water intrusion. This allows the collection grids to be at least partially exposed above the dielectric barrier, making it easy to make electronic connection to the devices.