Luminescent Metal-Nucleobase Network Thin Films by Atomic/Molecular Layer Deposition

Controlled molecular deposition of natural organic molecules such as nucleobases (NBs) into well-defined thin films represents progress toward exciting new nanomaterials. The strongly emerging atomic/molecular layer deposition (ALD/MLD) technique provides us with an elegant way to realize the depositions through gas phase with atomic/molecular level accuracy. In the resultant thin films the organic molecules are bound together not only with hydrogen bonds but also via metal cation linkers and are likely to exhibit novel properties. Here we demonstrate the ALD/MLD of such thin films with monovalent sodium, divalent barium, or trivalent lanthanum as the metal linker and uracil or adenine as the NB component. Our metal-NB thin films are homogeneous, smooth, and in the case of sodium and barium also crystalline showing intense photoluminescence. We discuss the impact of the size and charge of the metal cation on the growth and properties of the films.