Microfibrillated Cellulose Embedded with KCl as a Solid-Dopant Matrix into an Electrolyte-Gated Transistor

Area of Science:

• Materials Science
• Electronics Engineering
• Electrochemistry

Background:

• Electrolyte retention in electrolyte-gated transistors (EGTs) often requires complex fabrication or viscous electrolytes.
• Developing simplified device architectures with stable performance is crucial for advancing EGT technology.

Purpose of the Study:

• To introduce a multifunctional solid-dopant matrix (SDM) for enhanced electrolyte retention and ion anchoring in EGTs.
• To investigate the performance of EGTs using different electrolyte configurations, including the novel SDM.
• To demonstrate the potential of the SDM for stable and high-performance transistor operation.

Main Methods:

• Fabrication of a solid-dopant matrix (SDM) using microfibrillated cellulose (MFC) embedded with potassium chloride (KCl).
• Systematic investigation of four electrolyte configurations: H2O, MFC:H2O, KCl:H2O, and MFC:KCl:H2O in transistor devices.
• Characterization of transistor performance, including on/off current ratio, threshold voltage, drain current, transconductance, and electrochemical window.

Main Results:

• The MFC:KCl SDM effectively retains electrolytes and anchors ions, simplifying EGT architecture.
• Transistors with MFC:KCl:H2O exhibited stable operation up to -2 V gate voltage with on/off ratios of ~10^3.
• The SDM compressed the electrochemical window, enabling stable operation and improved performance (Vth=-0.7 V, Idmax=~10^-3 A, Gmmax=~3x10^2 mS) compared to ionic reference devices.

Conclusions:

• Microfibrillated cellulose-based materials offer a versatile platform for both field-effect and electrochemical transistors.
• The developed MFC:KCl SDM significantly enhances EGT stability and performance while simplifying device fabrication.
• This approach aligns with green electronics initiatives by utilizing sustainable materials and avoiding synthetic polymers.