Improved Thermal Stability under High Power Conversion Efficiency Condition in Inverted Ternary Organic Solar Cells with Three Different Electron Transport Layers

The efficiency of organic solar cells (OSCs) is influenced by various factors, among which environmental temperature plays a significant role. Previous studies have shown that the thermal stability of these cells can be enhanced by incorporating a third component into their structure. Ternary organic solar cells, in particular, have shown promising results in improving thermal stability. A well-designed electron transport layer (ETL) can significantly bolster thermal stability by facilitating efficient charge transport and reducing charge recombination. In this study, we investigated the effect of temperature on the efficiency of inverted ternary structures, ranging from 300 K to 400 K. The structures examined include FTO/SnO2/PM6:D18:L8-BO/PEDOT: PSS/Ag, FTO/Spiro-OMeTAD/PM6:D18:L8-BO/PEDOT: PSS/Ag, and FTO/PC60BM/PM6:D18:L8-BO/PEDOT: PSS/Ag. Through simulations employing three different electron transport layers—SnO2, Spiro-OMeTAD, and PC60BM—we observed that at 340 K (65°C) these structures maintained 92% of their original high efficiency of ~20% at 300 K, which represents a high level of thermal stability under the high PCE condition.