Increasing Volume in Conjugated Polymers to Facilitate Electrical Doping with Phosphomolybdic Acid

Area of Science:

• Materials Science
• Organic Electronics
• Chemical Engineering

Background:

• Molecular p-type dopants are crucial for tuning optoelectronic properties of organic semiconductors.
• Phosphomolybdic acid (PMA) is an effective dopant for solution-based processing.
• Controlling polymer film properties is key for optimizing doping efficiency.

Purpose of the Study:

• To investigate the role of polymer film volume in solution-based p-type doping using PMA.
• To understand how film volume affects the infiltration of PMA into polymer matrices.
• To correlate film volume with the resulting electrical doping levels.

Main Methods:

• Polymer film volume was controlled by thermal treatment and swelling solvent techniques.
• Solution-based doping was performed using phosphomolybdic acid (PMA).
• ³¹P NMR and FTIR spectroscopy were used to confirm the integrity of the PMA Keggin structure.

Main Results:

• Two methods were employed to control polymer film volume prior to doping.
• ³¹P NMR and FTIR confirmed the preservation of the PMA Keggin structure during doping.
• Increased polymer film volume significantly enhanced PMA infiltration and thus the p-type doping level.

Conclusions:

• Polymer film volume is a critical parameter for optimizing solution-based p-type doping with PMA.
• Facilitating PMA infiltration through volume control leads to higher electrical doping efficiency.
• This study provides insights for designing advanced organic electronic devices through controlled doping processes.