Efficient inverted perovskite solar cells with CuSeCN as the hole transport material

We demonstrate herein a mixed solvent containing organic amines and water for the solution processing of CuSeCN and apply it as the hole-transport material for stable and efficient inverted perovskite solar cells for the first time. The obtained CuSeCN film is characterized with X-ray diffraction spectrum, X-ray photoelectron spectroscopy, scanning electron microscope , and current-potential characteristics. High-quality perovskite film can be formed on the CuSeCN film obtained from the spin-coating of CuSeCN solution in a mixture solvent of H 2 O, ethanolamine (ETA), ethylenediamine (EDA), diethanolamine (DTA) with volume ratio of 2:6:1:1. The CuSeCN-based perovskite solar cell yields power conversion efficiency of 15.61% at forward scan and 15.97% at reverse scan with negligible hysteresis and good stability. As compared to the typically used thioether-based solvents for the solution processing of CuSCN , the mixture solvent proposed in this work is less volatile and much cheaper, which is critical for practical applications of perovskite solar cells .