Design of Combinatorial Shadow Masks for Complete Ternary-Phase Diagramming of Solid State Materials

We report on a novel mask design for the combinatorial synthesis of a ternary composition spreads library, which allows such libraries to be deposited through a series of simple masks on a rotatable mount. This eliminates the use of complicated actuation of a heated substrate. In our configuration, this design leads to a standard linear phase diagram by varying the growth rate of each constituent nearly linearly from 0 to 100% at a triangular area on the substrate. Film growth occurs as a series of cycles in which one molecular layer of the material is deposited over the entire area of the spread by a synchronization of the mask movement, target exchange, and laser pulses. The technique has been applied to the synthesis of photoluminescent TbCa₄O(BO₃)₃-ScCa ₄O(BO₃)₃-PrCa₄O(BO₃) ₃, demonstrating its value for the mapping of direct relationship between composition and the light-emitting property.