Thermal degradation analysis of sealed perovskite solar cell with porous carbon electrode at 100°C for 7000 h

Organic‐inorganic CH3NH3PbI3‐based perovskite solar cells have received significant research interest; however, thermal stability issue still remains. Carbon‐based triple‐porous‐layer perovskite solar cells without any hole transporting material were selected in order to investigate the internal degradation process by thermal stresses. The sealed perovskite solar cells at 100 ˚C showed stable performance in the power conversion efficiency up to 4500 h, but the degradation was accelerated after that. By analyzing the perovskite solar cells aged for 7000 h at 100 ˚C, the results of energy dispersive X‐ray spectroscopy and Fourier transform infrared spectroscopy suggest that, although Pb, I, and N were sealed inside of the devices, a plenty amount of CH3NH3+ deactivated in the sealant UV‐curable adhesive at 100 ˚C, which is the reason of the thermal degradation for the sealed perovskite solar cells.