Lead-free perovskite materials for optoelectronic and solar energy applications

Abstract

Lead-free halide perovskites have attracted growing attention as sustainable alternatives to their lead-containing counterparts, offering reduced toxicity and potentially improved long-term stability for photovoltaic and optoelectronic applications. However, the field remains fragmented, with widely varying synthesis strategies, stability benchmarks, and performance metrics, making it difficult to identify consistent design principles. This review provides a critical and integrative evaluation of the most recent advances in lead-free perovskite materials, highlighting structure-property-stability correlations across different perovskite families including Sn-, Bi-, Ge-, and Sb-based systems, as well as double and vacancy-ordered perovskites. Unlike previous reviews, this article introduces a comparative analysis that connects chemical composition, crystal dimensionality, and electronic structure with experimentally observed photovoltaic performance and degradation pathways. It also compiles and evaluates emerging trends in interface modification, defect passivation, and compositional engineering aimed at mitigating oxidation and moisture sensitivity. In addition, the review surveys recent computational and data-driven screening strategies that enable predictive design of stable, efficient lead-free perovskites. By critically mapping both progress and persisting challenges, this work provides a coherent framework for future materials development and device integration, positioning lead-free perovskites as key candidates for sustainable next-generation solar energy technologies.