The project focused on novel techniques in growth and characterization which may enhance group III - nitride applications. On the growth side nitride deposition on diamond templates was characterized as the most promising novel growth techniques. The continuing progress can be supported applying the novel characterization technique described below. Local inhomogeneities are a common feature in group III - nitrides. With standard characterization methods such materials cannot be properly evaluated. Multiple group III - nitride epilayers were investigated utilizing VEELS in combination with high resolution TEM in order to characterize the materials in high spatial and energy resolution. It was found that possible side effects such as sample damage due to electron irradiation or falsified results due to retardation effects can be avoided if proper sample treatment is applied. It is assumed that the occurrence of local electronic transitions in close vicinity to interfaces is due to the presence of local point or surface defects. For the first time it may become possible to investigate the impact of such defects on the performance of devices. For the InGaN alloy system nano-cluster formation which changes optical responses was investigated. It was found that the III-V compound InN exists as a composite InN:In material. InN commonly exhibits multiple optical responses including an interface and/or surface related effect, which triggered confusing scientific models in the past. The prospect of exploiting multiple energy transitions within ONE material offers completely new alternatives for novel device development.