Impact of Manufacturing Processes on the Nanostructure and Thermal Stability of Bulk Heterojunctions for Organic Solar Cells: A Study of D18 and PTQ10 Blends with Y6.

The proposed experiment aims to investigate the impact of manufacturing processes on the internal structure and thermal stability of bulk heterojunction (BHJ) organic solar cells (OSCs). Specifically, the study focuses on the thin films formed by two semiconducting polymers, D18 (purely paracrystalline) and PTQ10 (semi-paracrystalline), blended with the small molecule acceptor Y6. These materials were selected due to their high power conversion efficiencies and their distinct structural behaviors, such as the absence of glass transition in D18 and the presence of a glass transition in PTQ10. The main objective is to analyze the influence of spin-coating deposition protocols and post-deposition thermal annealing on the crystallinity, phase separation, and thermal degradation of these blends, with the aim of understanding their impact on OSC performance and long-term stability.
A combination of Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) and Grazing Incidence Small Angle X-ray Scattering (GISAXS) techniques will be employed to characterize the nanostructures of the pure compounds (D18, PTQ10, Y6) and their blends (D18, PTQ10). Additionally, both ex-situ and in-situ experiments will be conducted under varying deposition and annealing conditions to track changes in the nano-morphology and structural order.
The experiment seeks to answer key questions related to the role of different polymers, deposition methods, and annealing in determining the initial morphology and phase segregation behavior of the films. By correlating film formation with thermal stability and degradation, the study will provide insights into optimizing manufacturing protocols for stable, high-performance organic solar cells. The results are expected to contribute to advancing the design of new materials and processes in organic photovoltaics.