Dielectric diffraction gratings for light-trapping in InGaAs-GaAs quantum well solar cells

The enhancement in short-circuit current density (Jsc) provided by a TiO2 diffraction grating composed of rectangular strips at the rear of an In0.21Ga0.79As-GaAs quantum well solar cell (QWSC) is investigated using finite-difference time-domain (FDTD) simulations. Optimisation of the grating height, periodicity and fill-factor yielded an enhancement of 5.3% in Jsc over the reference cell.