Solution-processed copper arsenic sulfide thin films for photovoltaic applications

The first copper arsenic sulfide (Cu3AsS4) thin filmswith densely-packed micron-sized grains are synthesized by heating nanoparticles in As2S5. XRD demonstrates conversion of tetragonal Cu3AsS4 nanoparticles to their orthorhombic polymorph, and Raman spectroscopy indicates the presence of an amorphous secondary phase. These films display promise for photovoltaic applications.