Development of organic semiconductors for single component homojunction solar cells

Research Project, 2026 – 2030

Organic photovoltaics (OPVs) offer significant advantages over traditional silicon-based ones, holding potential for flexible, cost-effective renewable energy solutions. However, OPVs face challenges related to efficiency and stability due to the intrinsic instability of bulk heterojunction (BHJ) structure formed from two-component active layers. To overcome this, we propose an innovative approach: single-component homojunction solar cells. Our hypothesis is that organic semiconductors with sufficiently high dielectric constants—comparable to inorganics—can enable efficient charge separation without the need for donor/acceptor blends. To achieve this, we employ three key material design strategies: 1) molecular engineering to optimize core size and side chains for higher dielectric constants, 2) large oligomers to enhance π-electron delocalization and exciton dissociation, and 3) highly crystalline polymers to extend exciton diffusion lengths. Additionally, doping and additives will further improve performance and stability. The research will combine molecular synthesis, detailed material characterization, and device fabrication through close interdisciplinary collaborations. In the short term, this project will open a new research direction in OPVs and advance our understanding of photogeneration in single-component systems. In the long term, it will position organic semiconductors on par with inorganics, significantly expanding their applications in organic electronics.