Effects of Hydrogenic-like Impurity on Exciton Ground-State and Binding Energy in In_xGa_(1-x)N/GaN Quantum Dots

Concerning the domino effect of built-in electric field and the three-dimension restriction,the effects of hydrogenic-like impurity on exciton ground-state and binding energy in InxGa1-xN/GaN quantum dots(QDs) are studied by means of a variation approach within the framework of effective-mass approximation.The results show that there are critical values on the structural parameters of the QDs(radius and height) and In content when there is hydrogenic-like impurity in the center of quantum dots.The exciton ground-state energy is reduced,and the exciton binding energy and the stability of exciton state are increased when the parameter is larger than the critical value.When the impurity position is on the upper interphase of ODs,the exciton ground-state energy is the lowest,the exciton binding energy the highest and the stability of exciton state the strongest.As the impurity moves to lower interphase of ODs,the ground-state energy increases and binding energy reduces.