Oriented haloing metal-organic framework providing high efficiency and high moisture-resistance for perovskite solar cells

A facile two-dimensional Pb-based metal-organic framework in hexagon sheet structure is developed, and an oriented haloing effect of framework is further demonstrated when it is composited with organic Spiro-OMeTAD layer based on experimental and model analysis. With the haloing effect, the composited layer shows the smoother surface, higher hydrophobicity and upshifted energy levels and electrical interfaces, in comparison to a pure Spiro-OMeTAD layer. When the composite layer is used as hole transfer layer in perovskite solar cells , the cell reveals the higher power conversion efficiency and moisture-resistance feather. The average efficiency of cell with the composite layer is 13.17%, which is 25% larger than that with pure Spiro-OMeTAD layer, and the cell can remain 54% efficiency of initial value even after 9 days in an environment of 30% relative humidity , in contrast, the efficiency of cell with pure Spiro-OMeTAD layer decays to 28% of initial value just after 7 days.