Structural effect on triphenylamine dibenzofulvene based interfacial hole transporting materials for high-performance inverted perovskite solar cells

The interface hole transporting layer (HTL) between NiOx and the perovskite has a beneficial on the cell performance of inverted perovskite solar cells (PSCs) since the cascade the energy levels. In this work, four new triphenylamine dibenzofulvene based organic hole transporting interfacial materials (SC-1-4) containing different structure architectures are designed for achieving high-performance inverted PSCs. The optical and thermal properties of those new compounds are investigated. The effects of morphology, energy level and charge transfer resistance of the device are also compared. As a results, the bilayer of NiOx/SC-4 is found to improve the energy level alignment, film morphology, crystallinity, hole transporting, which enables the high quality of perovskite layer and the interfacial contact behavior. Thus, the NiOx/SC-4 based inverted device achieve the highest cell performance of 19.86%, negligible hysteresis and long-term stability. The results demonstrate the highly efficient cell properties of the triphenylamine dibenzofulvene based interfacial hole transporting materials for inverted PSCs.