Tailored electronic properties of Zr-doped SnO2 nanoparticles for efficient planar perovskite solar cells with marginal hysteresis

The optimal interface of perovskite solar cells contributes to efficient charge collection and transport for leading high power conversion efficiency. Despite SnO2 is a commonly used electron transport materials for perovskite solar cells due to wide band gap and n-type semiconducting property, shallow conduction band edge and low electrical conductivity of pristine SnO2 limit the full potential for efficient electron extraction from perovskite absorber. To improve the electrical property of SnO2, we design and synthesize Zr-doped SnO2 nanoparticles, in which tailored electronic structure affords enhanced conductivity, adjusted energy levels and excellence in electron extraction capability. Consequently, the champion device employing Zr-doped SnO2 nanoparticles achieves a power conversion efficiency of 19.54%, while the pristine SnO2 nanoparticles yield 17.30% under 100mWcm(-2) illumination. The systematic device analyses confirm that Zr-doped SnO2 delivers reduced interfacial resistance, reduced current leakage and suppressed charge recombination, which leads to not only the enhanced power conversion efficiency but also reduced hysteresis for the planar perovskite solar cells.