Application of Two-Dimensional MoSe₂ Atomic Layers to the Lift-Off Process for Producing Light-Weight and Flexible Bifacial Cu(In, Ga)Se₂ Solar Cells

Abstract

The application of two-dimensional MoSe2 atomic layers to the lift-off process is proposed for the preparation of light-weight and flexible bifacial Cu(In, Ga)Se2 (CIGS) solar cells. The results show that CIGS solar cells are successfully peeled from a Mo rear contact when the c-axis of the MoSe2, formed between the Mo and CIGS layers, is vertically oriented to the Mo surface. In this study, 11.5% efficient lift-off cells are fabricated, indicating a high-performance ratio of 95.0% compared with the 12.1% efficient substrate cells, thereby suggesting the usefulness of layered-grown MoSe2 for the lift-off procedure. Finally, by applying the lift-off process, light-weight and flexible bifacial CIGS solar cells utilizing thin Au and Sn-doped In2O3 back contacts are derived.