NOVELTY - The device has an absorber layer (106) formed on a conductive layer (104) including a structure with gaps between grains. A protection layer (120) is formed in the gaps between grains of the absorber layer. A buffer layer is formed on the absorber layer. A top transparent conductor layer is formed over the buffer layer. An additional transparent conductive layer is formed between the buffer layer and the top transparent conductor layer. The absorber layer includes thickness of between about 0.2 microns to 4.0 microns. The conductive layer is formed on a substrate (102) i.e. glass substrate.    USE - Photovoltaic device for use in electronic devices i.e. polycrystalline thin film solar cells, at homes, buildings and vehicles. Can also be used for light sensors and photosensitive devices.    ADVANTAGE - The thin insulating layer prevents contact with a bottom electrode and provides better adhesion between the grains so as to prevent lift off or mechanical film failure. The device maximizes copper-zinc-tin-sulfur (CZTS) efficiency by making a tandem cell with an amorphous silicon cell including higher band gap, thus allowing more effective light harvesting across a solar spectrum, while reducing undesirable interactions and promoting pristine and high quality material layers in an efficient manner. The device improves absorber structures by preventing mass migration between the grains in the structures.    DETAILED DESCRIPTION - The protection layer is a thin insulating layer. The conductive layer is a transparent conductive layer (108). The structure is a granular structure. The absorber layer is made of a copper-zinc-tin material with a chalcogenide material. The buffer layer is made of a material selected from a group consisting of a cadmium sulfide material, cadmium tellurium material, zinc sulfide material, zinc-oxide-sulfur material, indium sulfide material and zinc oxide material. The protection layer is an aluminum oxide layer. The conductive layer is made of a molybdenum layer.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a photovoltaic device.    Substrate (102)    Conductive layer (104)    Absorber layer (106)    Transparent conductive layers (108-110)    Protection layer (120)