Interestingly, thin films are among the least commonly investigated material forms for PSs. To the best of our knowledge, thin-film synthesis has only been reported for six of the 258 experimentally synthesized PSs present in the ICDS database (Fig. ). All of them are thiophosphates: BiPS 4 , Cu 3 PS 4 , Sn 2 P 2 S 6 , Li 3 PS 4 , Na 3 PS 4 , and members of the Li-Ge-P-S system . Relevant optoelectronic characterization was conducted for BiPS 4 and Cu 3 PS 4 , but these films consisted of spin-or drop-cast nanoparticles and may not be fully representative of fully coalesced polycrystalline films. The other films were grown by standard deposition techniques (thermal evaporation or pulsed laser deposition) but they were not optoelectronically characterized.