Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, Taiwan ; State Engineering University of Armenia (SEUA), Yerevan, Armenia ; Yerevan State University, Faculty of Physics

Physics ; Interfaces ; Electronic structure and electrical properties of surfaces ; Low-dimensional structures

The concept of intermediate-band (IB) solar cells (SC) offered the promise of achieving higher conversion efficiency devices than the multi-junction SCs [1]. Like the conventional solar cells, IB SCs exploit one-photon absorption for generation the photocurrent. However, these SCs also exploit the two-consecutive-photon induced electrons transitions via the intermediate states for generation an extra photocurrent [2,3] . In fact, the IB SC concept exploits nonlinearity in absorption and must gain from the sunlight concentration.