Efficiency enhancement of perovskite solar cells with a buffer layer

The perovskite solar cell using solvent treatment on active layer and a thin buffer layer added was fabricated and characterized. The morphology of MAPM3 active layer agglomerates owing to methylbenzene treatment and the perovskite solar cell shows an increased short circuit current density (Jsc). An efficient buffer layer, the 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), which enhances device performance by forming well interfacial contact and restraining the hole from transporting to the cathode. The optimized perovskite solar cell showed an open circuit voltage (Voc) of 0.90 V, Jsc of 13.44 mA/cm2, fill factor (F.F.) of 64.69%, and power conversion efficiency (PCE) of 7.81% under simulated AM1.5G illumination of 100 mW/cm2, respectively.