Advancements in perovskite/CIGS tandem solar cells: Material synergies, device configurations, and economic viability for sustainable energy

The growing demand for renewable energy is driving innovations in solar technology for both outdoor and indoor applications. However, higher efficiency, improved stability, and cost-effectiveness are the highest priorities for the commercialization of solar cells. Recently, tandem solar cells (T-SCs) have emerged as a promising solution to surpass the efficiency limits of traditional single-junction cells. By integrating materials like perovskite and copper–indium–gallium–selenide (CIGS), T-SCs capture a broader spectrum of sunlight, improving power conversion efficiency. Perovskite’s wide bandgap (∼1.6 eV) absorbs high-energy photons, while CIGS’s narrower bandgap (∼1.1 eV) optimizes lower-energy photon absorption. This review examines recent developments in perovskite/CIGS T-SCs, highlighting the complementary properties of these materials and their impact on photocurrent generation. It also compares two-terminal (2-T) and four-terminal (4-T) configurations, achieving efficiencies of 24.6 and 30.1%, respectively. Additionally, the economic potential of perovskite/CIGS T-SCs is explored, focusing on their role in reducing energy costs and enhancing sustainability. Key challenges and future directions are also discussed to advance renewable energy systems.