produced several temperature windows with stable, self-limiting deposition of GaN. The ALD process chemistry was self-limiting up to at least 400 °C. A similar gas-phase decomposition mechanism as In(triaz)3, rendering a tricoordinated Ga amide, was suggested to explain this behaviour. Films grown at 350 °C afforded GaN that grew epitaxially on 4H-SiC (0001) with an atomically smooth interface (Figure ), a Ga/N ratio Given the similar sublimation temperatures of these new triazenide precursors, mixing them in the ALD precursor source was tested for ALD of the ternary nitride In1-xGaxN. Coevaporation of the precursors into the ALD reactor resulted in In1-xGaxN films, with the composition (value of x) being tuneable based on deposition temperature, sublimation temperature, and mixing ratio. In1-xGaxN films with x-values ~0.5 are known to be metastable, precipitating out InN or In metal. This presents a challenge for crystal growth, which must occur at temperatures below 500 C. Consequently, ALD is particularly intriguing for these meta-stable materials, as it operates at temperatures where the chemisorbed monolayers remain stable. The In1-xGaxN films grew epitaxially on 4H-SiC (0001) and investigations by TEM show no signs of precipitation of InN (Figure ). A gradient on the composition was, however, noted, rendering approximately In0.18Ga0.82N towards the substrate, and In0.82Ga0.18N towards the film surface (Figure and). This was speculated to be due to stress minimization with a smaller lattice mismatch to 4H-SiC with higher Ga-content. The bandgap of a In0.55Ga0.45N film deposited on Si (100) was measured to be 1.94 eV.