GaN-based structures grown on SiC substrates by means of horizontal hot-wall metal-organic chemical vapor deposition (MOCVD) were systematically characterized, revealing high crystal quality. The hot-wall MOCVD grown GaN, doped by Mg and Si, respectively showed low-resistivity hole and electron transport, competitive with the state-of-the-art GaN. High concentrations of free holes (similar to 2 x 10(17) cm(-3)) were achieved for the as-grown Mg-doped GaN without thermal annealing, thanks to advantageous heating characteristics of the "hot-wall" reactor. The analysis of optical and electrical properties brought a picture, where Mg is the only impurity defining energy levels in the hot-wall MOCVD p-type doped GaN. Besides, InGaN/GaN light-emitting diodes employing such doped GaN materials in the carrier-transport layers were fabricated, resulting in high device performances. The devices exhibited bright electroluminescence with very narrow full widths at half maximum as well as negligible spectral shifts at high current levels (greater than or similar to 10 A/cm(2)). These results exemplified the rewards of the hot-wall MOCVD for development of high-quality nitrides-based structures, providing an attractive growth method to realize the demonstration of light-emitting devices with favorable properties.