Atomic layer deposition (ALD) and chemical vapour deposition (CVD) are important techniques to deposit thin films for a variety of applications. Metal oxides and nitrides are used as passivation layers and as dielectrics, and due to the increasingly small sizes of microelectronic devices, their depositions must be precise, conformal, and of high purity. This work examines how precursor design can reduce impurities in deposited films. Several novel precursors have been designed, synthesized, and characterized, and used to deposit a variety of group 13 nitride thin films. Bidentate ligands such as guanidinates, NacNacs and azenides have been explored, as have simpler ligand systems such as amides and hydrides. The importance of precursor design is emphasized due to the fact that it enables the development of new, volatile, and thermally stable compounds and ALD processes that will deposit pure, high-quality films in a cost- and time-efficient manner.