TAGRA 2025

Perovskite solar cells (PSCs) have rapidly advanced in recent years, achieving impressive power conversion efficiencies. However, challenges such as sensitivity to heat, moisture, and the need for high-temperature processing hinder their long-term stability and commercialization. Traditional PSCs typically use electron transport layers (ETLs) alongside hole transport layers (HTLs) to facilitate efficient charge extraction, but these ETLs often require complex and costly fabrication steps. Specifically, the device structure studied, as shown in Figure 1, consists of the following layers: fluorine-doped tin oxide (FTO), formamidinium tin triiodide (FASnI3) as the absorber layer, doped polyanilinine/graphene oxide (PANI/GO) as the hole transport layer (HTL), and silver (Ag). This study focuses on lead-free, ETL-free perovskite solar cells, which simplify device architecture and enable low-temperature, cost-effective manufacturing suitable for large-area applications. Eliminating the ETL and using lead-free absorber materials results in devices that are more environmentally friendly and scalable. SCAPS-1D simulation software was used to analyze the impact of interface defect densities and defect tolerance on device performance. The results highlight the critical importance of interface engineering, especially at the FTO/absorber interface, which has a stronger influence on device parameters than the absorber/HTL interface. Reducing the interface defect density to around 1×1011 cm-2 is essential to minimize charge recombination and energy losses, leading to significant improvements in power conversion efficiency (PCE), fill factor, and stability. This work demonstrates that careful management of interface quality and defect passivation allows ETL-free, lead-free PSCs to achieve performance comparable to more complex architectures without relying on toxic elements or high-temperature processes. These insights pave the way for developing stable, efficient, and eco-friendly perovskite solar cells with simpler fabrication routes, supporting the future of sustainable photovoltaic technology.