Numerical investigation of Sulfamoylbenzoic acid-functionalized MXene interface modifier for high efficiency perovskite solar cells

In the pursuit of sustainable, high-efficiency energy solutions, perovskite (PVT) solar cells (PSCs) have emerged as promising candidates due to their tunable optoelectronic properties and low-cost fabrication. However, commercialization remains hindered by efficiency stagnation and interfacial instability, particularly at the buried electron transport layer (ETL)/PVT interface. To address this, a novel interfacial modification strategy is proposed using MXene functionalized with 4-sulfamoylbenzoic acid (MX-Sba) as an interlayer at the ETL/PVT junction in cesiumformamidinium (CsFAMAPbIBr2)-based PSCs. The carboxylic acid-terminated MX-Sba improves conductivity, energy level alignment, and defect passivation, facilitating efficient charge extraction and reduced non-radiative recombination. Numerical simulations revealed favorable band bending, charge carrier mobility, and interfacial transport characteristics. A detailed analysis underscores the impact of interfacial defect density and resistance variations on charge dynamics and device performance. The optimized device exhibits a remarkable power conversion efficiency (PCE) of 25.15%, with a short circuit current density (J sc ) of 24.35 mA/cm 2 , open circuit voltage (V oc ) of 1.262 V, and fill factor (FF) of 81.81%. These findings establish MX-Sba as a multifunctional interface modifier and outline a scalable pathway for developing efficient, durable PSCs for clean energy applications.