Enhancing efficiency of perovskite solar cells using a thin buffer layer

Abstract A perovskite solar cell was fabricated; the active layer was treated with a solvent and a thin buffer layer was inserted. Methylbenzene treatment caused large agglomeration in the MAPbI 3 active layer in the perovskite solar cell, reducing the series resistance (R s ). 1,3,5-Tris( N -phenylbenzimidazol-2-yl)benzene (TPBi) formed an efficient buffer layer, which enhances the performance of the device by improving interfacial contact between cathode and hole blocking layer and by preventing transportation of the holes to the cathode. The perovskite solar cell herein had an open circuit voltage (V oc ) of 0.90 V, a short circuit current density ( J sc ) of 13.44 mA/cm 2 , a fill factor (F.F.) of 64.69%, and a power conversion efficiency (PCE) of 7.81% under simulated AM1.5G illumination of 100 mW/cm 2 .