Development of Back Surface Texture for Light Management in Epitaxial Lift Off (ELO) Quantum Dot Solar Cells

Quantum dot (QD) solar cells with light management allow for increased QD absorption without the need for excessive strain balancing. Single-junction GaAs cells with 10 QD layers are fabricated with back surface reflectors (BSRs) and removed from the substrate by epitaxial lift off. Devices with different BSRs will be compared: a flat mirror, a periodic texture that varies in one dimension, a periodic texture that varies in two dimensions, and a random texture achieved by crystallographic etch. Initial results show a 40% increase in sub-band current when comparing devices with a 1-D texture to the flat mirror. The final paper will present development and device results from the other two BSR types.