Advancing the Stability and Efficiency of Halide Perovskite Solar Cells

Significance 

Halide perovskite solar cells have gained significant attention in recent years due to their exceptional performance and potential to revolutionize the field of solar energy. These solar cells are composed of a unique class of materials called halide perovskites, which exhibit remarkable light-harvesting properties and can efficiently convert sunlight into electrical energy. Halide perovskite solar cells have demonstrated remarkable power conversion efficiencies, exceeding 25%. This level of performance rivals and even surpasses that of conventional solar technologies such as silicon-based solar cells. The high efficiency of halide perovskite solar cells makes them an attractive option for generating renewable electricity. One of the key advantages of halide perovskite solar cells is their low production costs. The materials used in these cells are abundant, easily synthesized, and can be processed at low temperatures, reducing manufacturing expenses. This cost-effectiveness makes halide perovskite solar cells a promising alternative for widespread deployment. They offer flexibility in design and fabrication. They can be deposited on various substrates, including flexible materials, enabling the production of lightweight, thin, and flexible solar panels. This versatility opens up possibilities for integrating solar cells into a wide range of applications and environments. Moreover, Halide perovskite solar cells can be seamlessly integrated into building materials, such as windows, façades, and rooftops. This integration allows buildings to generate clean energy while maintaining aesthetic appeal. BIPV offers the potential to transform urban landscapes into energy-generating structures. Furthermore, the lightweight and flexible nature of halide perovskite solar cells makes them suitable for powering portable electronics and wearable devices. These solar cells can be incorporated into mobile phones, smartwatches, fitness trackers, and other small electronic gadgets, providing a renewable and portable power source.

Indeed, Halide perovskite solar cells have the potential to bring affordable and sustainable electricity to remote areas without access to a centralized power grid. Their low production costs and high efficiency make them ideal for off-grid applications, such as powering rural communities, remote sensing devices, and agricultural equipment. The lightweight and high-efficiency characteristics of halide perovskite solar cells make them promising for use in solar-powered vehicles. By integrating these solar cells into the body or roof of electric vehicles, it becomes possible to generate clean energy to charge the vehicle’s battery and extend its range. Halide perovskite solar cells hold promise for large-scale solar power plants. Their high performance and low production costs make them an attractive option for utility-scale electricity generation. By harnessing the power of halide perovskite solar cells, countries can significantly increase their renewable energy capacity and reduce reliance on fossil fuels.

Although halide perovskite solar cells have emerged as a highly attractive option due to their high performance and low production costs. However, concerns regarding the long-term stability of these solar cells have hindered their widespread adoption. In a new study led by Dr. Juan-Pablo Correa-Baena, an assistant professor at the School of Materials Sciences and Engineering, Georgia Tech, researchers investigated the thermal stability and structural changes occurring within the interface layers of halide perovskite solar cells. Their findings shed light on the challenges associated with these cells and provide valuable insights for improving their reliability and efficiency. The research work is now published in the journal Advanced Materials.

To unravel the complexities surrounding the stability of halide perovskite solar cells, the research team designed a sample solar device comprising multiple independent solar cells. This setup allowed them to study the performance of the cells with and without surface treatments using large cations. These cations, while improving conversion efficiency, were previously believed to be stable after deposition. However, the team’s experiments revealed that the interfaces of these cells undergo thermal instability, leading to changes in the material’s structure.

The authors subjected the pre-treated samples to thermal stress at 100 degrees Celsius and analyzed the resulting changes using advanced characterization techniques. X-ray photoelectron spectroscopy enabled them to measure changes in the chemical composition of the samples, while another X-ray technique provided insights into the crystal structures formed on the film’s surface. By combining these tools, the researchers visualized the diffusion of cations into the lattice and observed how the interface structure changed under heat exposure.

To understand the impact of cation-induced structural changes on solar cell performance, the authors employed excitation correlation spectroscopy. This technique exposed the solar cell samples to pulses of light and measured the resulting light emission intensity. By analyzing these measurements, the researchers could determine the presence of surface defects that negatively affected energy conversion.

The authors’ findings indicated that organic cations used for passivation in halide perovskite solar cells slowly permeate the perovskite film under thermal stress. This permeation impedes charge extraction and increases nonradiative recombination, resulting in a decrease in power conversion efficiency. The authors also observed that the type of cations used played a significant role in the speed and extent of these changes, suggesting that proper engineering of the interface layer could enhance the stability of halide perovskite solar technology.

The study underscores the importance to explore the stability of interfaces at high temperatures and develop new passivation molecules that do not reconstruct the perovskite film surface. By avoiding the diffusion and reconstruction of the perovskite bulk, it may be possible to achieve enhanced stability and prolonged device lifetimes. Additionally, testing solar cells at temperatures above 55 degrees Celsius becomes imperative to accurately assess their stability and performance.

The recent research led by Dr. Juan-Pablo Correa-Baena and his colleagues provides crucial insights into the thermal stability and structural changes occurring within the interface layers of halide perovskite solar cells. By uncovering the challenges associated with organic cation treatments and their impact on solar cell performance, the study paves the way for improved engineering and design strategies. Future developments in passivation molecules and comprehensive testing protocols will play a crucial role in realizing the full potential of halide perovskite solar technology, ensuring enhanced stability, efficiency, and long-term viability in the pursuit of sustainable energy solutions.

Reference

Carlo Andrea Riccardo Perini, Esteban Rojas‐Gatjens, Magdalena Ravello, Andrés‐Felipe Castro‐Mendez, Juanita Hidalgo, Yu An, Sanggyun Kim, Barry Lai, Ruipeng Li, Carlos Silva‐Acuña, Juan‐Pablo Correa‐Baena. Interface Reconstruction from Ruddlesden–Popper Structures Impacts Stability in Lead Halide Perovskite Solar Cells. Advanced Materials, 2022; 34 (51): 2204726 DOI: 10.1002/adma.202204726

Go To Advanced Materials

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