28.3% efficient perovskite-silicon tandem solar cells with mixed self-assembled monolayers

Abstract A certified 28.3% efficient monolithic perovskite-silicon tandem (PST) solar cell with a mixed self-assembled monolayer (SAM) containing carbazole cores with H-ligands (2PACz) and methoxy-ligands (MeO-2PACz) is reported. Our analysis revealed that there existed uncovered areas of MeO-2PACz on indium tin oxide, which would be caused by the steric effect, and they were filled with 2PACz in the mixed SAM, leading to the improvement of fill factors in the PST cells. This result was explained by the passivation qualities as hole transport layers and the local interaction between methoxy ligands and perovskite materials.