Doping of [In2(phen)3Cl6]·CH3CN·2H2O Indium‐Based Metal–Organic Framework into Hole Transport Layer for Enhancing Perovskite Solar Cell Efficiencies

Perovskite solar cells (PSCs) have gained a promising position during the past few years. However, as far as it goes, there is rare combination of the merits of metal–organic framework with PSCs. In this work, a 3D metal–organic framework, namely, [In₂(phen)₃Cl₆]·CH₃CN·2H₂O (In2) is first introduced into hole transport material of PSCs through band alignment engineering. By this facile strategy, the pinholes in the hole transport layer are effectively reduced, and the migration of Au into the entire PSC structure can be alleviated simultaneously. Meanwhile, In2 also plays a role in enhancing the light absorption of perovskite, which is due to: (1) the large particles of In2 acting as light scattering centers; (2) the emission wavelength of In2 is almost the same as the excitation wavelength of perovskite. Consequently, short‐current density (J_sc), open circuit voltage (V_oc), and fill factor (FF) gain a significant increase from 19.53 to 21.03 mA cm^?2, 0.98 to 1.01 V, and 0.67 to 0.74, respectively. Thereby, the power conversion efficiency is remarkably enhanced from 12.8% to 15.8%. In the end, the stability of PSCs should also be improved.