Fig. 11

Impact of interface defects ((10¹⁰ cm^− 2 to 10¹³cm⁻²) on the performance of the bottom subcell (a) IV curve and (b) PV parameters for TiO₂/Cs₂TiI₆ ( ETL/absorber layer) interface (c) IV curve and (d) PV parameters for Cs₂TiI₆/PEDOT (absorber layer/HTL) interface.