The design of 1 eV band-gap of GaNAs/InGaAs short-period super-lattice solar cell

The GaNAs/InGaAs short-period super-lattice(SPSL) with a feature of space separation in In and N constituent and equivalent 1 eV band-gap is one of important structures as an active region to achieve high efficiency of GaInNAs- based solar cell in the future. To experimentally realize the required band-gap for high conversion efficiency in multi- junction solar cells on Ge substrate, we demonstrate a propagation matrix method to calculate some dependences of GaNAs/InGaAs SPSLs on their structural parameters. The results show that the GaNAs/InGaAs SPSL structures can be flexible to obtain the 1 eV energy gap by a reasonable choice of the period number, barrier thickness as well as concentrations of In and N. Additionally, the calculation illustrates a relationship of respective modulation from those super-lattice structures for the SPSL active region which emits or absorbs light at 1 eV in energy.