“…In an early state of technology, new polycrystalline absorber materials suffer from inhomogeneous films and especially pinholes in the absorber layer . Examples are Sb 2 S 3, , SnS, and lead-free perovskites. , In the case of more optimized lead-based perovskites, the complex mechanisms of film formation from solution , can be controlled by certain spin-coating processes, which yield compact, homogeneous, and pinhole-free perovskite layers for small-scale devices in the lab. − For up-scaled industrial fabrication, spin-coating is not suitable and the applied deposition methods face more processing constraints such as high yields, high throughput, and low solvent toxicity. , As of today, pinholes in the absorber layer remain an issue in up-scaled perovskite fabrication , as well as in the already established thin-film photovoltaic technologies CdTe, − Cu(In,Ga)Se 2 (CIGS), , and thin-film silicon …”