Intermediate-band solar cells based on quantum dot supracrystals

The authors show that the ordered three-dimensional arrays of quantum dots, i. e., quantum dot supracrystals, can be used to implement the intermediate-band solar cell with the efficiency exceeding the Shockley-Queisser limit for a single junction cell. The strong electron wave function overlap resulting in minibands formation allows one to tune the band structure and enhance the light absorption and carrier transport. A first-principles semianalytical approach was used to determine the optimum dimensions of the quantum dots and the interdot spacing to achieve a maximum efficiency in the InAs0.9N0.1/GaAs0.98Sb0.02 quantum dot supracrystal photovoltaic cells. (C) 2007 American Institute of Physics.