High-Efficiency and Stable Carbon-Based Planar Perovskite Solar Cells
Author | : Vijayaraghavan Sankaranarayanan Nair |
Publisher | : |
Total Pages | : 0 |
Release | : 2023 |
ISBN-10 | : OCLC:1396228429 |
ISBN-13 | : |
Rating | : 4/5 (29 Downloads) |
Book excerpt: Perovskite solar cells (PSCs) have attracted much attention both in research and industrial domains. The power conversion efficiencies (PCE) of PSCs have been improved from 3.8% to 25.8% in just over a decade, rivaling that of silicon solar cells. Hybrid perovskite materials have exceptional optoelectrical properties and can be processed using cost-effective solution-based methods. In contrast, the fabrication of silicon solar cells requires high-vacuum, high-temperature, and energy-intensive processes. The combination of excellent optoelectrical properties and cost-effective manufacturing makes hybrid perovskite a winning candidate for solar cells.As the PCE of PSCs improves and their long-term stability increases, one of the crucial hurdles to be addressed is the cost-effective scalable fabrication and its long-term stability. Most high-efficiency solar cells require an energy-consuming method of depositing the cathode to complete the cell. These high-efficiency devices also require highly expensive noble metal electrodes. Herein, following recommendations from the literature, carbon-based nanomaterials are utilized, and their effects on the efficiency, fill factor (FF), open-circuit voltage (Voc), and short circuit density (Jsc) are analyzed. The PSCs and carbon counter electrodes are fabricated at low temperatures (~100 degrees Celsius). As per the literature, carbon-based devices exhibited an efficiency of >19%. This endeavor further buttresses the fact that carbon nanomaterials are promising candidates for the future of low-cost, high-performance, and scalable production of PSCs. Thus, complex vacuum deposition of expensive cathodes to complete the cells might be eliminated.In this thesis, I focus on several novel interface engineering techniques, that can reduce the surface roughness of the carbon electrode, and improve the interface it forms with the underlying layer. These interfacial engineering techniques improved the charge collection efficiency of the carbon, and thereby reduced the recombination happening at the interface. As a result, the PCE could be enhanced from ~13% to >18%.In addition to these techniques, a high-quality narrow band gap perovskite layer was developed with low dimensional 2D perovskite passivation to further improve the device performance. Together with the improved perovskite film quality and optimized film composition, along with interface engineered carbon electrode, an impressive PCE of >21% was attained.