Enhanced Performance in Bulk Heterojunction Polymer Solar Cell Using Water Soluble Conjugated Polymer
Journal of Nanoscience and Nanotechnology
|September 11, 2015
Summary
Researchers developed a water-soluble polymer, poly[(9,9-bis((6'-(N,N,N-trimethylammonium)hexyl)-2,7-fluorene))-alt-bisphenylfumaronitrile]dibromide (AHF-alt-PFN), to enhance polymer solar cell performance. This polymer improved short circuit density and power conversion efficiency when used as an interfacial layer.
Area of Science:
- Materials Science
- Polymer Chemistry
- Renewable Energy
Background:
- Bulk heterojunction polymer solar cells (BHJ-PSCs) are a promising renewable energy technology.
- Improving the efficiency and stability of BHJ-PSCs is crucial for their commercial viability.
- Interfacial layers play a significant role in optimizing charge transport and device performance.
Purpose of the Study:
- To synthesize and characterize a novel water-soluble conjugated polymer, poly[(9,9-bis((6 -(N,N,N-trimethylammonium)hexyl)-2,7-fluorene))-alt-bisphenylfumaronitrile]dibromide (AHF-alt-PFN).
- To investigate the effect of incorporating this polymer as an interfacial layer in BHJ-PSCs.
- To evaluate the impact of ion doping within the polymer interfacial layer on device performance.
Main Methods:
- Suzuki type of polymerization reaction was employed for polymer synthesis.
- Fabrication of BHJ-PSCs using poly(3-hexylthiophene):phenyl-C61 butyric acid methyl ester (P3HT:PCBM) as the active layer.
- Introduction of the synthesized water-soluble polymer (AHF-alt-PFN) as an interfacial layer between the active layer and the cathode, with and without specific ion doping (Cs+, F-, CO2-(3)).
Main Results:
- The synthesized polymer (AHF-alt-PFN) exhibited good solubility in methanol.
- Devices incorporating the poly(AHF-alt-PFN) interfacial layer showed enhanced short circuit density and power conversion efficiency.
- The presence of negative ions (F-, CO2-(3)) in the poly(AHF-alt-PFN) layer resulted in a 1.3 to 2.3 times higher short circuit current density compared to devices without the ion-doped layer.
Conclusions:
- The water-soluble polymer poly(AHF-alt-PFN), particularly when doped with negative ions, effectively enhances BHJ-PSC performance.
- Improved device performance is attributed to increased electron mobility within the polymer layer and a reduced electron barrier at the cathode interface.
- This study demonstrates a viable strategy for improving polymer solar cell efficiency through advanced interfacial engineering.
