Overcoming the Interface Losses in Planar Heterojunction Perovskite-Based Solar Cells

A scalable, hysteresis‐free and planar architecture perovskite solar cell is presented, employing a flame spray synthesized low‐temperature processed NiO (LT‐NiO) as hole‐transporting layer yielding efficiencies close to 18%. Importantly, it is found that LT‐NiO boosts the limits of open‐circuit voltages toward an impressive non‐radiative voltage loss of 0.226 V only, whereas PEDOT:PSS suffers from significant large non‐radiative recombination losses.