Multijunction solar cells concept based on GaP/Si nanostructures

The lattice-matched GaP/Si superlattice is proposed to be used as an active material for top junction, which is grown on n–GaP/p-Si heterojunction bottom sub cell. Computer simulations demonstrate that GaP/Si structures with 1-2 nm Si quantum wells allow one to obtain a material with an effective band gap of 1.4–1.6 eV. GaP/Si nanostructures were grown at 380 °C by plasma deposition using PE-ALD and PECVD for GaP and Si layers growth, respectively. Structural, optical and electrical properties of GaP/Si nanostructures grown on Si and GaP wafers are reported and discussed in terms of photovoltaic application.