Partial filling of a quantum dot intermediate band for solar cells

This paper describes how to partially fill the intermediate band formed by the confined states of quantum dots with electrons. Efficiencies of up to 63.2% have been calculated in ideal cases for solar cells with this intermediate band. In order to achieve this, the barrier region is n-doped so that the electrons delivered by the donors fall into the otherwise empty intermediate band states. This method produces a fully space-charged structure whose electrostatic properties are studied in this paper, thus confirming the feasibility of the proposed method. Partial filling of the intermediate band is necessary to provide strong absorption in transitions from it to both the valence and the conduction bands.