Improving the performance through SPR effect by employing Au@SiO2 core-shell nanoparticles incorporated TiO2 scaffold in efficient hole transport material free perovskite solar cells

Hole transport material free (HTM-free) perovskite solar cells (PSCs) with carbon counter electrode have the advantages of low-cost, good efficiency and high stability. Here in this work, we demonstrate that incorporating Au@SiO2 core-shell NPs into TiO2 scaffold layer increases the power conversion efficiencies (PCEs) of PSCs by improving the light absorption and facilitating carrier transfer or separation through SPR effect. With the optimal concentration of 0.3 wt % Au@SiO2 incorporation, the average PCE of PSCs enhances to 13.85 ± 0.45% from the reference samples of 12.01 ± 0.44%, which is mainly caused by the improved short circuit current density.