NOVELTY - Forming a dense semiconductor film involves formulating an ink of particles in which about greater than or equal to 50% of the particles are microflakes each containing at least one element from group IB, IIIA and/or VIA and having a non-spherical, planar shape, where overall amounts of elements from group IB, IIIA and/or VIA contained in the ink are such that the ink has a desired stoichiometric ratio of the elements; coating a substrate with the ink to form a precursor layer; and processing the precursor layer in a suitable atmosphere to form a dense film.    USE - For forming dense films useful in the formation of a semiconductor absorber of a photovoltaic device (claimed) and solar cells.    ADVANTAGE - Planar shape of the microflakes creates greater surface area contact between adjacent microflakes that allows the dense film to form at a lower temperature and/or shorter time as compared to a conventional film made from a precursor layer using an ink of spherical nanoparticles in which the nanoparticles have a similar material composition and the ink is otherwise identical to the ink. The method provides high-throughput printing of semiconductor precursor layer from microflake particles. The planar particles disperse more easily, form much denser coatings (or form coatings with more interparticle contact area), and anneal into fused, dense films at a lower temperature and/or time than their counterparts made from spherical nanoparticles. The method provides more efficient and simplified creation of dispersion of planar particles and the resulting coating of the dispersion. Even unstable dispersions using large microflake particles that may require continuous agitation to stay suspended still create good coatings. The planar shape of microflakes also allows for improved packing density, and the geometry of the microflakes allows for more intimate contact than spherical particles or nanoparticles in the precursor layer. Thus, the planar shape of the microflakes creates a higher packing density in the dense film as compared to a film made from a precursor layer using an ink of spherical nanoparticles of the same composition, i.e. the microflakes create a packing density of at least about 90 % in the precursor layer.    DETAILED DESCRIPTION - Forming a dense semiconductor film involves formulating an ink of particles in which about greater than or equal to 50% of the particles are microflakes each containing at least one element from group IB, IIIA and/or VIA and having a non-spherical, planar shape, where overall amounts of elements from group IB, IIIA and/or VIA contained in the ink are such that the ink has a desired stoichiometric ratio of the elements; coating a substrate with the ink to form a precursor layer; and processing the precursor layer in a suitable atmosphere to form a dense film. The film is formed from the precursor layer of the microflakes and a layer of a sodium containing material in contact with the precursor layer.    DESCRIPTION OF DRAWING(S) - The figure shows a flowchart of a method of forming dense film.