  On the basis of a quantum microscopic approach we study the cooperative
effects induced by the dipole-dipole interaction in an ensemble of point-like
impurity centers located near a charged perfectly conducting surface. We
analyze the simultaneous influence of the modified spatial structure of field
modes near the conductive surface and the electric field on the transition
spectrum of an excited atom inside an ensemble and on the radiation trapping.
We show that the electric field modifies the cooperative Lamb shift, as well as
the character of sub- and superradiant decay. We also demonstrate that these
modifications differ from those taking place in the case of atomic ensembles in
free space, without conducting surface.
