Asymmetric effects of interfacial defects, recombination velocity, and temperature on perovskite solar cell performance

Perovskite solar cells (PSCs) have achieved efficiencies nearing 30%, but interfacial recombination remains a critical challenge. This study employs Atlas TCAD finite element simulations to investigate the combined effects of surface recombination velocity (SRV, 10 to 10⁷ cm/s) and interfacial defect density (Nt, 10¹⁴ to 10¹⁷ cm⁻³) on PSC performance across four architectures: TiO₂ or SnO₂ as electron transport layers (ETLs) and NiO or Spiro-OMeTAD as hole transport layers (HTLs). The results reveal a significant asymmetry: the ETL/perovskite interface is highly sensitive to recombination losses, with TiO₂-based devices showing greater degradation than SnO₂-based ones, while the perovskite/HTL interface remains robust. NiO-based devices outperform those using Spiro-OMeTAD, particularly at high defect densities, and exhibit enhanced stability at moderate temperatures (40–55°C). Temperature-dependent analysis shows that TiO₂/perovskite interfaces degrade above 55°C, highlighting the need for targeted passivation strategies. These findings, supported by experimental evidence of HTL dopants' role in recombination, provide actionable guidelines for interface engineering, advancing the development of efficient, stable PSCs for sustainable energy applications.