In certain desirable embodiments, the present invention relates to the use of 15N isotopes into GaAsN, InAsN or GaSbN films for ion beam analysis. A semiconductor-nitride assembly for growing and analyzing crystal growth in a group III-V semiconductor sample that includes: a substrate; a buffer layer deposited on the substrate, a nitrogen gas injector to incorporate enriched nitrogen gas and the nitrogen gas injector includes a concentration of enriched nitrogen gas, a thin film consisting of at least one group III element containing compound where at least one group III element is covalently bonded with the nitrogen in the presence of the same or different group V element of the buffer layer, and a proton beam to analyze the incorporation of the nitrogen gas in the thin film layer is described.