Achieving flexible higher efficiency GaInP/GaAs/InGaAs solar cells by 40-period quantum well superlattices

Abstract

Quantum-well tandem solar cells have been shown to achieve higher efficiencies due to a more matched bandgap combination. But beyond 100-period quantum wells, the stress balance of the epitaxial layer will become extremely difficult, especially for large-sized epitaxial layers. In this paper, a more economical 40-period InGaAs/GaAsP quantum well superlattices are used to achieve excellent spectral control of 8 cm² GaInP/GaAs/InGaAs solar cells. Under the AM0 spectrum, the short-circuit current density of the triple-junction solar cells increased from 16.859 mA/cm² to 17.665 mA/cm², benefiting from the external quantum efficiency of approximately 40 % in the expanded spectral band of the 40-period quantum wells. Compared with conventional flexible GaInP/GaAs/InGaAs solar cells, the addition of 40-period quantum wells increased the efficiency from 32.30 % to 33.47 % (AM0). The 40-period quantum well superlattices is an effective parameter to achieve higher efficiency and large-area flexible triple-junction solar cells.