Researchers Make Significant Breakthrough in Developing Safer, More Efficient Solar Panels

Researchers Achieve a ‘Pivotal Step’ Towards Developing Next-Generation Solar Panels

Scientists at the Autonomous University of Querétaro in Mexico have made a significant breakthrough in the field of solar energy by discovering a method to enhance the stability and efficiency of perovskite solar cells, a type of thin-film technology, without relying on conventional lead halide perovskites, which carry health and environmental risks, as reported by Tech Xplore. Their findings were published in the journal *Optical and Quantum Electronics*.

Solar panels consist of individual solar photovoltaic cells, also known as solar cells, which utilize technology to convert sunlight’s photons into electricity. The Department of Energy states that silicon is the predominant semiconductor material used in most solar cells, owing to its abundance on Earth and its high efficiency in energy conversion. Currently, silicon solar cells dominate the market, accounting for 95% of all solar modules sold.

Emerging on the scene are perovskite solar cells—thin-film cells constructed with layers of materials that are either printed, coated, or vacuum-deposited onto a substrate. These layers enable the solar cell to absorb light, separate charge particles, and generate an electrical circuit, facilitating the flow of electricity. The potential for employing printing technology to create perovskite layers makes these solar cells economically appealing for the industry, significantly reducing production costs. Moreover, perovskite solar cells exhibit high efficiency in converting light to energy, rivaling traditional silicon cell technology. Over the past decade, researchers have achieved more than a 20% improvement in efficiency for these cells.

However, a notable drawback is the prevalent use of lead halide perovskites in these cells. According to *Solar Magazine*, lead halide perovskites can lead to environmental contamination by leaching lead into the soil, adversely affecting local ecosystems and the food chain. Lead exposure in humans can result in anemia and high blood pressure in adults, as well as hinder brain development and hearing in children.

Driven to find a sustainable alternative to lead halide perovskites, the researchers at the Autonomous University of Querétaro explored a chalcogenide perovskite—(Ca,Ba)ZrS3—composed of calcium (Ca), barium (Ba), zirconium (Zr), and sulfur (S). This perovskite demonstrates robust thermal and chemical stability and possesses a tunable bandgap that aligns with the optimal range for solar energy absorption, reaching 1.26 eV. According to an article in *Joule*, the ideal bandgap for photovoltaic materials lies between 1 and 1.8 eV.

The researchers combined this innovative perovskite with advanced inorganic spinel hole transport layers, which facilitate the movement of positively charged particles, or “holes,” to their designated areas within the electrical circuit, thereby generating electricity. Upon testing the performance of this new perovskite solar cell, the team successfully enhanced its power conversion efficiency to an impressive rate of over 34% by meticulously adjusting layer thickness, carrier concentration, and interface properties.

If viable, these perovskite solar cells could dramatically reduce production costs, making cleaner energy more accessible to consumers. Transitioning to solar energy also mitigates global reliance on fossil fuels, which contribute to greenhouse gas emissions that elevate global temperatures and lead to extreme weather conditions. Increased access to solar energy can also improve air quality, reducing the risks of respiratory illnesses and related health issues.

“The future of solar energy is being reshaped, and we are honored to contribute to this promising transformation,” said Latha Marasamy, one of the researchers involved in the study.