RESUMEN
High-efficiency quantum dot sensitized solar cells (QDSSCs) can be received by increasing quantum dot (QD) loading and mitigating QD surface trap states. Herein, the surface state of CuInS2 QDs is optimized through an I-/MPA dual-ligands passivation strategy. The steric hindrance and electrostatic repulsion between QDs can be effectively reduced, thereby enabling an increased QD loading capacity. Meanwhile, the I-/MPA dual-ligands passivation strategy can further lower the surface trap density, leading to substantially enhanced charge transfer efficiency of the solar cells. Interestingly, various iodized salts, including TBAI, MAI, and KI, are proved to possess comparable property, underscoring the versatility and broad applicability of this I-/MPA dual-ligands passivation strategy. Eventually, CuInS2 QDSSCs based on the NH4I/MPA dual-ligands exhibit a noteworthy enhancement in photovoltaic conversion efficiency, surpassing the benchmark of 5.71% to reach 7.03%.