Vacuum deposited perovskite solar cells employing dopant-free triazatruxene as the hole transport material

- Triazatruxene core as hole transport material for perovskite solar cells.
- Extremely thin film (20 nm) can efficiently extract hole in perovskite solar cells.
- Highly efficient devices can be fabricated using vacuum evaporation of triazatruxene as well as perovskites.

Planar perovskite solar cells using organic charge selective contacts were fabricated. In a vacuum deposited perovskite-based solar cell, dopant and additive free triazatruxene as the hole transport layer was introduced for device fabrication. High open-circuit voltage of 1090 mV was obtained using methylammonium lead iodide (Eg=1.55 eV) as light harvesting material, thus representing a loss of only 460 mV which is in close vicinity of mature silicon technology (400 mV). The devices showed a very competitive photovoltaic performance, monochromatic incident photon-to-electron conversion efficiency of 80% and the power conversion efficiencies in excess of 15% were measured with a negligible degree of hysteresis.