Applications of high efficiency multi-junction solar cells are still limited by their high cost, which is determined by high price of fabrication procedures and complex device structure with strong electrical, radiation, and thermal coupling between device elements. As today, the multi-junction cells can find commercial applications with cheap light concentrators that provide at least 400 Suns. The alternative Q-BIC photovoltaic technology proposed here allows for effective harvesting and conversion of wide spectrum solar radiation by charged quantum dots placed in one junction. Structure of Q-BIC solar cell is relatively simple. It does not require formation of specific band structure with intermediate bands and its fabrication is based on the well-established technological procedures. For these reasons, Q-BIC cells have a strong potential to combine high conversion efficiency with relatively low cost. Moreover, due to huge effect of optical pumping, the harvesting and conversion of IR radiation significantly increases with the usage of concentrators. These features provide numerous possibilities to employ Q-BIC cells together with available cheap concentrators in various commercial applications. Light weight and improved radiation resistance make this technology especially suitable for military and aerospace applications.
Thus, main competitors of our product in the market are multi-junction solar cells. Our advantages compared to them are: a) existence of well-developed fabrication technologies; b) relatively low cost: compared with multi-junction solar cells our approach does not require matching of crystalline lattices, thermal coefficients, and photoinduced currents in the cascade of heterojunctions. Compared with the intermediate band solar cell, Q-BIC devices do not require the formation of the intermediate band which is a huge technological problem; c) numerous possibilities for nano-engineering and further improvements due to high scalability of nanoblocks (dots, dot planes, dot clusters, etc); and d) strong improvement of IR conversion with enhanced light concentration due to huge effect of optical pumping on IR photocurrent from Q-BIC cells.