Zirconium- and hafnium-based chalcogenide perovskites: From materials to devices and applications

Chalcogenide perovskites (CPs) based on zirconium (Zr) and hafnium (Hf) are becoming increasingly attractive as a new class of materials for next-generation solar cells. CPs with the ABX3 structure stand out due to their attractive optical and electrical properties, such as efficient light absorption, direct bandgaps in the range of 1.1–2.1 eV, and remarkable defect tolerance, making them a compelling alternative to hybrid and double perovskites for solar energy conversion. Although theoretical studies have progressed rapidly, experimental verification still faces challenges such as the high synthesis temperatures required (>900 °C), particularly in producing high-quality, phase-pure thin films and scalable solution-based processes. In this review, we aim to provide a comprehensive overview of the progress and remaining obstacles in advancing CP-based materials and devices. First, we describe the structure and composition as well as the different CPs in which the B site is occupied by Zr and Hf. Second, we summarize the methods used and the challenges that researchers face in producing an effective device. We highlight the main features that make CPs a preferred option for photovoltaic and other applications. Third, we look at the progress made in simulating solar cells that can achieve a power conversion efficiency (PCE) of over 30% using SCAPS-1D software. In the end, challenges and future research directions toward the development of CP materials and devices are provided. Overall, this review will serve as a valuable resource for researchers in selecting suitable strategies to achieve high-performance optoelectronic devices.