Built-in potential and ground state switching in coupled InGaN/GaN quantum wires

Built-in potential and ground state switching in coupled In0.2Ga0.8N/GaN quantum wires (QWRs) is investigated as a function of barrier width between QWRs. In the case of a relatively thin barrier thickness, the ground state wave function of hole exists in the upper QWR region while that of electron exists in the lower QWR region because the lowest and the highest built-in potentials exist in the upper and the lower QWRs, respectively. However, the difference of bottom energies in the lower and upper QWRs is gradually decreased with increasing barrier width between QWRs. As a result, in the case of a relatively thick barrier thickness (Lb≥40Å), we observe that the ground state switching of hole and electron wavefunctions occurs.