Rapid Microwave Annealing for Improved Crystallinity and Morphology of Perovskite Materials

Abstract

Perovskite solar cells are gaining significant attention for their remarkable power conversion efficiency, cost-effective processing, and material abundance. This study investigates the impact of rapid microwave annealing on the crystallinity and morphology of MAPbI₃ films on FTO glass substrates. Multifaceted characterization techniques, including field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV–Vis spectroscopy, photothermal deflection spectroscopy (PDS), and steady-state photoluminescence (PL) measurements are used to compare microwave-annealed samples with traditional hotplate-annealed samples. Microwave annealing yields significantly larger crystals in shorter processing times, suggesting enhanced crystallinity, as evidenced by SEM analysis and XRD data. UV-Vis and PDS measurements indicate improved optical properties and reduced sub-bandgap states, while PL results suggest diminished nonradiative recombination in microwave-annealed samples. However, a partial film detachment has been observed at higher microwave powers, a phenomenon explained by COMSOL simulations. These findings demonstrate rapid microwave annealing as an energy-efficient and cost-effective alternative while highlighting the need for further optimization to address film degradation issues, which remain a significant challenge. This research supports the potential for scalable, high-quality perovskite material production, facilitating large-scale production and commercialization of next-generation solar cells.