Researchers from Mexico's Autonomous University of Querétaro recently addressed PSCs' stability and toxicity concerns by exploring chalcogenide perovskites, specifically ABSe3 (where A = Ca, Ba, and B = Zr, Hf), as alternatives. These materials exhibit excellent optoelectronic properties, superior thermal and structural stability, and a non-toxic composition, making them ideal candidates for efficient, lead-free solar cells.
The research team investigated the integration of CaZrSe3, BaZrSe3, CaHfSe3 and BaHfSe3 as absorber layers in solar cells. The scientists optimized their performance using the Solar Cell Capacitance Simulator in One Dimension (SCAPS-1D), a computational tool developed at the University of Ghent. This simulation allowed them to analyze the behavior of these materials under real-world conditions.
The results indicated significantly enhanced device efficiency and viability for practical applications by fine-tuning critical parameters such as carrier concentration, defect density, and absorber layer thickness.
The team's approach led to improved light absorption, increased resistance to recombination, strengthened built-in potential, and minimized non-radiative recombination and charge transfer resistance. Additionally, the careful optimization enhanced the band alignment between each layer and improved the interface properties, resulting in remarkable increases in PCE.
Simulations indicated that solar cells using CaZrSe3 and BaZrSe3 could exceed 30% PCE, a significant leap compared to conventional absorber materials. These improvements are attributed to enhanced short-circuit current density, increased quasi-Fermi level splitting, a higher carrier generation rate, elevated electric field strength, and larger quantum efficiency measurements, all of which contribute to superior efficiency.
This work marks a step toward the development of lead-free, high-performance solar absorbers. As part of their ongoing efforts, the scientists aim to refine these materials further to ensure they are not only efficient but also scalable and cost-effective.
In addition to improved efficiency, the integration of these materials has the potential to reduce production costs, enhance long-term operational stability, and provide a safer alternative to conventional perovskite solar cells. With continued experimental validation and further material optimization, chalcogenide perovskites could revolutionize the renewable energy sector, paving the way for a future powered by clean, reliable, and environmentally friendly solar technology.
