Secondary Effects of Alkylammonium Cations on Perovskite Solar Cells

Abstract

The rapid increase in fossil fuel usage during the onset of industrialization has led to a significant rise in the Earth's average temperature. The Paris Agreement underscores the urgent need for global collaboration to reduce greenhouse gas emissions, achieve net-zero carbon emissions, and mitigate the impacts of climate change, including the growing prevalence of climate-related disasters. As a result, researchers have been exploring renewable energy sources, focusing on solar cells as a major alternative. Perovskite solar cells (PSCs) have emerged as a promising solution due to their low-cost, lightweight, flexible, and translucent properties, along with a laboratory efficiency of over 26%. However, their commercialization is hindered by stability issues and environmentally unfriendly manufacturing methods. In this study, we investigate methods to improve the stability and efficiency of PSCs, focusing on the effects of different manufacturing techniques on FAPbI3 film characteristics and the role of alkylammonium chloride in the A site. Additionally, an eco-friendly manufacturing process using ethanol-based perovskite solutions is proposed. A novel method for creating bifacial PSCs that can receive light from both sides is also introduced, utilizing methylamine with volatile properties. Chapter 3 discusses the application of FAPbI3 perovskite in solar devices, examining the impact of different preparation methods on the performance and stability of PSCs. The one-pot and sequential spin-coating methods are compared, and the incorporation of isopropylammonium cations (iPAmH+) at the perovskite layer's grain boundaries in the sequential process is proposed. Model experiments demonstrate that adding isopropylammonium chloride (iPAmHCl) to the FAPbI3 precursor solution in the one-pot process enhances the stability and efficiency of PSCs. Chapter 4 explores eco-friendly methods for producing large-area PSCs, focusing on an innovative technique using a 1:1 mixture of dimethylacetamide (DMA) and ethanol (EtOH) with added alkylammonium chloride (RNH3Cl) to create a stable FAPbI3 perovskite precursor solution, enabling the formation of high-efficiency PSCs without the use of toxic solvents. In Chapter 5, a new approach for creating bifacial PSCs is proposed, utilizing the self-healing phenomenon of MAPbI3 and recycling the methylamine (MA) gas generated from the thermal decomposition of MAPbI3. The gas produced at the interface aids in merging the MAPbI3 into a single layer. This allows to produce double-sided PSCs using only inorganic charge transport layers while using TCO for both anode and cathode. The efficiency achieved using pure MAPbI3 is close to 19%, comparable to conventional structures employing noble metals and organic CTL.