Metal halide perovskites for energy applications: recent advances, challenges, and future perspectives

Metal halide perovskites (MHPs) have rapidly emerged as a leading class of materials for a wide range of energy applications, including photovoltaics, light-emitting devices, and energy storage systems. Their exceptional optoelectronic properties such as high absorption coefficients, long carrier diffusion lengths, and tunable bandgaps combined with their low-cost, solution-processable synthesis methods, position MHPs at the forefront of next-generation sustainable energy technologies. Despite these advantages, critical challenges remain, particularly concerning their long-term operational stability, environmental toxicity (especially due to the lead content), and scalability for industrial production. This review comprehensively examines recent progress in the synthesis and characterization of MHPs, focusing on key breakthroughs in materials design, processing techniques, and analytical tools that deepen our understanding of their structure property performance relationships. We also discuss the primary bottlenecks limiting commercial deployment and highlight emerging strategies to improve device durability, reduce ecological impact, and enhance compatibility with scalable manufacturing processes. Finally, we offer a forward-looking perspective on promising research directions aimed at expanding the applicability of MHPs beyond photovoltaics, including their potential roles in thermoelectric conversion, solid-state batteries, and advanced optoelectronic sensors, thereby underscoring their transformative potential in the future of clean energy technologies.