Use of InGaAs/GaSb Quantum Ratchet in p-i-n GaAs Solar Cell for Voltage Preservation and Higher Conversion Efficiency

The concept of intermediate band solar cell (IBSC) is evolved through the effective use of the below bandgap photons, so as to improve upon the existing Shockley-Queisser limit for single-junction solar cells (SCs). But there are many challenges with the IBSC, for which they are unable to achieve the theoretical maximum. One of the most important constraints is the increase in recombination rate (both radiative and nonradiative), which results in a significant reduction in open-circuit voltage. In this paper, an antimonide-based quantum photon ratchet SC is proposed, where an InGaAs/GaSb quantum ratchet band is introduced into the IBSC. It reduces the transmission losses effectively by decoupling the intermediate band (IB) from the valence band, thereby increasing the lifetime of charge carriers in the IB state leading to increase in the conversion efficiency over IBSC.