Abstract
Introducing spiro-OMeTAD as protecting layer for onto CH 3 NH 3 PbI 3 /TiO 2 in a liquid-type perovskite solar cell is found to suppress the degradation of the device efficiently. Evidenced by XRD analysis, the dissolution of onto CH 3 NH 3 PbI 3 /TiO 2 is significantly retarded in the presence of spiro-OMeTAD capping layer and consequently the currentvoltage parameter decay is stabilized.