Nitride-based materials still offer opportunities for the development of new electronic and optoelectronic applications. From the seventies of the 20th century, GaAs was considered as mature family material for many electronic applications. In the beginning of the 21th century, GaAs is step by step replaced by GaN in many applications due to its high polarization, chemical and physical stability, and wide bandgap. In this work we study theoretically the electronic and optoelectronic properties of GaN, and we conceive its applications. We test the triangular quantum well model for the high...