InAs quantum dot growth on Al<i>x</i>Ga1−<i>x</i>As by metalorganic vapor phase epitaxy for intermediate band solar cells

Abstract

InAs quantum dot multilayers have been grown using AlxGa1−xAs spacers with dimensions and compositions near the theoretical values for optimized efficiencies in intermediate band photovoltaic cells. Using an aluminium composition of x = 0.3 and InAs dot vertical dimensions of 5 nm, transitions to an intermediate band with energy close to the ideal theoretical value have been obtained. Optimum size uniformity and density have been achieved by capping the quantum dots with GaAs following the indium-flush method. This approach has also resulted in minimization of crystalline defects in the epilayer structure.