Bifacial Perovskite Solar Cells by Lamination Approach With a PEDOT:PSS/d-Sorbitol Blended Adhesion Layer

초록

Bifacial perovskite solar cells (PSCs) generate electricity by absorbing light from both their front and rear sides. These PSCs are constructed by laminating two prefabricated half-cells into a bifacial device. However, insulating lamination layers can degrade adjacent layers and increase series resistance, thereby compromising device performance. Herein, we present an efficient lamination method for bifacial PSCs under low-temperature and low-pressure conditions. Specifically, a blend of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and a hydroxyl-rich compound, d-sorbitol, is employed as a conductive adhesive layer. We incorporated d-sorbitol into PEDOT:PSS to provide adhesive character and enable lamination of the two substrates. We also found that hydrogen bonding between d-sorbitol and PSS reduces the Coulombic attraction between PEDOT and PSS. This promotes rearrangement of the PEDOT chains into a more closely packed structure with enhanced π–π stacking. These changes improve conductivity and surface uniformity. As a result, the conductive adhesion layer enables an intimate interconnection between the two laminated components of the laminated bifacial PSCs (LBPs). Notably, the optimal LBP exhibits a power conversion efficiency of 19.17% under 1-sun illumination and 27.54% at an albedo value of 0.5. Overall, this lamination strategy provides an effective approach to fabricate efficient bifacial PSCs under low-temperature and low-pressure conditions.

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