MBE growth of 1.7eV Al0.2Ga0.8As and 1.42eV GaAs solar cells on Si using dislocations filters: an alternative pathway toward III-V/ Si solar cells architectures

Metamorphic epitaxial growth of III-V solar cells on Si has attracted significant interest for the development of III V/Si photovoltaic architectures. In this work, we present an alternative pathway – using MBE growth techniques – based on the direct nucleation of Al_{x}Ga_{1-x}As materials on Si, followed by the growth of a 1.7eV Al_{0.2}Ga_{0.8}As or a 1.42eV GaAs solar cell. Dislocation Filter Layers (DFLs), in conjunction with Thermal Cycle Annealing (TCA), have been used to reduce the Threading Dislocation Density (TDD) below 10^{7}cm^{-2} in the base of the cell; close to the best results demonstrated with metamorphic buffers