Photovoltaic device and a method for preparation thereof

A method for preparing a photovoltaic device comprising at least one photovoltaic cell, the method comprising:

• providing a semi-transparent substrate,
• forming a stack of layers of the photovoltaic cell on the substrate, the stack comprising:
• a front electrode layer, a back electrode layer, and a photoactive layer between the front electrode layer and the back electrode layer, wherein one of the front electrode layer and the back electrode layer constitutes an anode of the photovoltaic cell and the other constitutes a cathode of the photovoltaic cell, wherein the photoactive layer is a perovskite layer and the back electrode layer is a carbon layer that is substantially free of perovskite,
• forming, by laser, apertures in the stack of layers of the photovoltaic cell such as to uniformly distribute the apertures within the photovoltaic cell, the apertures extending through at least the front electrode layer, the back electrode layer, and the photoactive layer such that the apertures are entirely surrounded by the front electrode layer, the back electrode layer, and the photoactive layer, each of the apertures including walls, the walls of the apertures forming substantially smooth surfaces and extending through at least the back electrode layer, the front electrode layer, and the photoactive layer;
• introducing a functionalizing agent into the apertures to fill the apertures by the functionalizing agent so that for each of the apertures a filling thickness of the functionalizing agent is less than or equal to a depth of the aperture and the filling thickness is at least 20% of the depth of the aperture, the functionalizing agent comprising at least one functionalizing ingredient selected from the group consisting of coloring ingredient, fluorescent and/or phosphorescent ingredient, moisture absorber, retro-reflective ingredient, quantum-dots improving light-guiding within the structure of photovoltaic device, ingredients improving mechanical strength of the photovoltaic device, heat insulator, microspheres serving as optical cavities, metal nanoparticles exhibiting a plasmonic effect, particles shifting down the spectrum and particles shifting up the spectrum.