Device with quantum dot layer spaced from delta doped layer

A method of forming a semiconductor device includes the following steps: providing a plurality of semiconductor layers; providing means for coupling signals to and/or from layers of the device; providing a layer of quantum dots disposed between adjacent layers of the device; and providing an auxiliary layer disposed in one of the adjacent layers, and spaced from the layer of quantum dots, the auxiliary layer being operative to communicate carriers with the layer of quantum dots.