The second potential problem with PS thin-film synthesis is dealing with M1-M2-P-S material systems where either M1 or M2 is a volatile metal. Such "problematic" metals are Group 1 (alkalis), Group 2 (alkaline earths), and Group 12 elements. Since volatile metals tend to sublime in vacuum at very low temperatures, they are difficult to sputter in a controlled manner and can cause contamination problems that are in some cases irreparable. To address this problem, we propose the inclusion of a very simple thermal evaporator with replaceable parts in the deposition suite (Fig. ). In this separate chamber, Group 2 and Group 12 elements (constituting, say, M1 in the M1-M2-P-S system of interest) can be deposited from metal sources, while the substrate is not intentionally heated. In a thermal evaporator, even Group 1 elements can be evaporated as pure metals by using alkali metal dispensers as sources . The volatile M1 can be evaporated before or after sputter deposition of a M2-P-S combinatorial library, and the resulting M1/M2-P-S film stack can be reactively annealed in the RRTP to aim for crystallization of the M1-M2-P-S material of interest. Due to the typically high solid-state diffusion coefficients in volatile metals, no significant kinetic barriers are expected for the diffusion of the M1 layer into the M2-P-S matrix. Glove-box integration is key for handling and transfer of the air-sensitive Group 1 and Group 2 metal thin films.