TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Parameter: At least the SiNx interlayer that is furthest from the substrate layer has a thickness of 0.5-10 nm and has GaN penetrating through its one or more portions, where the first GaN layer has two or more SiNx interlayers in it. The semiconductor wafer further comprises a layer of multiple quantum wells (MQWs) formed between the second GaN layer and the p-doped semiconductor layer, and where the thickness of the layer of MQWs is preferably 10-100 nm. The thickness of the substrate is 275-1000 mu m; and/or the thickness of the first GaN layer is 0.1-5 mu m; and/or the thickness of each SiNx interlayer is 0.5-10 nm; and/or the thickness of the second GaN layer, where present, is 50-2000 nm; and/or the thickness of the AlGaN layer, where present, is 100-1500 nm; and/or the thickness of the AlN layer, where present, is 10-300 nm; and/or the thickness of the p-doped semiconductor layer, where present, is 50-1000 nm. Preferred Component: The GaN penetrates through one or more portions of at least one SiNx interlayer to form discrete crystalline structures within the GaN enclosing the SiNx interlayer. The GaN penetrates through portions of the SiNx interlayer across the interlayer. The semiconductor wafer further comprises an aluminum gallium nitride (AlGaN) layer between the substrate layer and the GaN layer and preferably further comprising an AlN layer between the substrate layer and the AlGaN layer. The substrate consists of silicon and unavoidable impurities. The AlGaN layer is compositionally graded so that the amount of aluminum decreases across the thickness of the layer away from the silicon substrate layer. The first GaN layer is not doped. The wafer further comprises a second GaN layer on the opposite side of the first GaN layer from the substrate, where the second GaN layer is n-doped, where the second GaN layer is n-doped with Silicon (Si) or Germanium (Ge). The second GaN layer is a compositionally graded Si- or Ge-doped GaN layer formed on the first GaN layer so that the amount of Si or Ge respectively increases across the thickness of the layer away from the GaN layer. The semiconductor wafer further comprises a p-doped semiconductor layer formed on the second GaN layer.