On some new effects in delta-doped QWs

•We describe new phenomenon connected to ionization of impurity delta layer within QW.•It leads to the increase of impurity binding energy.•Effect of distribution model of the impurity within delta-layer is negligible.•Ionization leads to a change of energy separation between energy levels in the QW.•The idea of an optical modulator controlled by a weak electric field is put forward.

Self-consistent calculation of Schrodinger, Poisson and electroneutrality equation with embedded impurity binding energy calculations of delta-doped SiGe/Si quantum well structures are performed. The influence of several parameters of the structure on the impurity binding energy is studied and discussed. On the basis of found phenomena the idea of an optical modulator controlled by a weak electric field is put forward.