Green-based modifiable CaZnBr4 for solar cells application

Future revolution in photovoltaics will be hinged mainly on cost, health implication, and material stability and performance. Based on these criteria, lead-based inorganic photovoltaics, organic–inorganic hybrid, and silicon photovoltaics are screened-out. According to the literature, the lead-free inorganic perovskite solar cell is favorably disposed to cost and safe-health. However, the simultaneous solution to material stability, high defect density, and low power conversion efficiency (PCE) still remains a mystery that has not been solved. This research proposed the green-based modifiable CaZnBr₄ as a potential candidate for lead-free solar cell application based on the principle of A-site cation with green-based additive incorporation. The green-based additive was obtained from Kola Nitida, Carica Papaya, Ficus Exasperata, and Musa paradisiaca. The elemental characterization of the green-based additives was performed using X-ray fluorescence spectroscopy (XRF). The optical, crystalline, and electronic properties were characterized using ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffractometry, Quantum Espresso, scanning electron microscopy and SCAPS-1D. The green-base-modified CaZnBr₄ showed significant PCE improvement by 3% with significant film and crystallinity formation. The stressed state of the parent compound CaZnBr₄ shows that it may be better suited for thermovoltaics application. It is recommended that better results could be obtained when different synthetic routes and green-based additives are used to initiate the defect passivation protocols.