We present a p-i-n structured solar cell with stacked layers of InxGa1−x N Quantum Dots (QDs) with
different indium composition. The photocurrent and surface recombination processes are investigated in the
i-region. We have shown that the QDs in the i-region can play the role of both generation or recombination
centers. The photocurrent has been calculated by self-consistent method to solve continuity equation of
charge carriers in the layers of the i-region. By changing the Indium composition in Inx Ga1−xN QDs, the
band gap of QDs varies and therefore provides a considerable overlapping with solar spectrum. Proposed
SC with different-sized QDs and different Indium composition leads to absorption of a desirable wavelength
range of solar spectrum and therefore a “rainbow” solar cell can be designed.