Donor impurity states and related optical responses in triangular quantum dots under applied electric field

•Linear and nonlinear optical coefficients in triangular quantum dots.•Donor impurity related optical transitions.•Triangular shaped quantum dot under applied electric field.•The electric field strengthens the impurity-related optical absorption response.•The electric field leads to a strong quenching of the interstate light absorption.

The linear and nonlinear coefficients for the optical absorption and relative refractive index change associated with transitions between donor impurity states in a two-dimensional quantum dot of triangular shape under applied electric field are calculated for y-polarization of the incident light. Both the effective mass and parabolic band approximations have been considered. The results show that the application of a DC electric field strengthens the impurity-related optical absorption response, with particular relevance in the case of the nonlinear contribution to it. However, for a fixed donor atom position inside the triangular quantum dot, the calculations show that the in-plane orientation of the applied field can becomes a critical parameter that may lead to a strong quenching of the interstate light absorption.