An ink for forming CIGS photovoltaic cell active layers is disclosed along
with methods for making the ink, methods for making the active layers and
a solar cell made with the active layer. The ink contains a mixture of
nanoparticles of elements of groups IB, IIIA and (optionally) VIA. The
particles are in a desired particle size range of between about 1 nm and
about 500 nm in diameter, where a majority of the mass of the particles
comprises particles ranging in size from no more than about 40% above or
below an average particle size or, if the average particle size is less
than about 5 nanometers, from no more than about 2 nanometers above or
below the average particle size. The use of such ink avoids the need to
expose the material to an H.sub.2Se gas during the construction of a
photovoltaic cell and allows more uniform melting during film annealing,
more uniform intermixing of nanoparticles, and allows higher quality
absorber films to be formed.