Dicyanamide-passivated perovskite coupled with Ni-ATA MOF for an efficient monolithic photo-supercapacitor

A monolithic photo-supercapacitor (PSC) integrating an ionic-liquid-passivated CsFAPbI 3 perovskite solar cell with a Ni-Aurintricarboxylic acid (ATA) metal-organic framework (MOF) supercapacitor, enabling efficient solar-energy harvesting and storage in a single unit, is presented. Surface modification of CsFAPbI 3 with 1-ethyl-3-methylimidazolium dicyanamide (EMIM + DCA − ) ionic liquid (IL) enables a void-free morphology and forms a chemically bonded interfacial bilayer comprising DCA − –Pb 2+ /FA + /Cs + interactions and outward-facing EMIM + cations. XPS, UPS, dark current and time-resolved photoluminescence (TRPL) analyses confirm strong IL–perovskite coordination, a 0.3 eV upward shift in the valence band maximum, a twelve-fold reduction in trap density and suppressed nonradiative recombination. The IL-treated solar cell achieves a PCE of 9.9%, with enhanced external quantum efficiency of 93% at 600 nm and a stability of seven days. When integrated into a monolithic PSC, the IL-passivated perovskite cell photo-charges the Ni-ATA//rGO storage unit to ∼0.65 V within 8 s under 1-sun illumination. The device delivers a specific capacitance of 86 mF cm −2 , an energy density of 5 μWh cm −2 at 161 μW cm −2 and maintains stable performance over 500 light-charging/dark-discharging cycles. The overall photo-charging and storage efficiency reaches 4.5%, demonstrating the potential of IL-engineered perovskites and MOF-based electrodes for integrated solar-energy conversion and storage platforms.