Synergistic Effect between NiOx and P3HT Enabling Efficient and Stable Hole Transport Pathways for Regular Perovskite Photovoltaics

As an inorganic hole transport material (HTM), nickel oxide (NiOx) is widely used in perovskite solar cells (PSCs) due to its low cost and intrinsic stability. However, on account of its poor film formation on perovskite, the low power conversion efficiency (PCE) and stability of regular NiOx-based PSCs is a main obstacle for commercialization. Here, a solution-processed inorganic/organic hybrid hole transporting system is developed to resolve this issue, thereby improving the PCE from 16.0% to 21.2%. Poly(3-hexylthiophene) (P3HT) is studied as the typical case, revealing that the performance improvement mainly lies in the synergistic interaction between NiOx and P3HT: 1) the introduction of P3HT improves assembly regularity and film uniformity of NiOx; 2) electron redistribution between P3HT and NiOx increases the Ni3+/Ni2+ ratio for higher hole mobility; 3) the feed-back impact of NiOx on P3HT enhances molecular orientation of polymer chains in P3HT for better hole transport through polymer framework. Finally, the encapsulated solar cell modules with P3HT-promoted NiOx maintains 91% of the initial efficiency after 1000 h aging at a harsh 85 degrees C/85% relative humidity condition. This finding provides a feasible approach for using NiOx-based HTMs to realize high-performance regular PSCs, paving the way for their commercialization.

Automated summary

By developing a solution-processed inorganic/organic hybrid hole transporting system, this research improves the application of nickel oxide in perovskite solar cells, enhancing the power conversion efficiency and stability.