Influence of Temperature Variation on Field Effect Transistor Properties Using a Solution-Processed Liquid...

Area of Science:

• Materials Science
• Organic Electronics
• Semiconductor Physics

Background:

• Organic semiconductors offer potential for flexible and low-cost electronic devices.
• Liquid crystalline (LC) semiconductors combine unique self-assembly properties with charge transport capabilities.
• Field-effect transistors (FETs) are key components in organic electronic circuits.

Purpose of the Study:

• To investigate the properties of the liquid crystalline (LC) semiconductor 8TNAT8 for fabricating organic field-effect transistors (OFETs).
• To analyze the effect of temperature variations and phase transitions on the performance and morphology of 8TNAT8-based LC FETs.
• To understand the relationship between the morphological changes of the LC semiconductor layer and its charge carrier mobility.

Main Methods:

• Fabrication of bottom-gate/bottom-contact type field-effect transistors (FETs) using a solution casting method with 8TNAT8.
• Characterization of FET properties, including carrier mobility (0.01 cm2 V-1 s-1).
• Investigation of surface morphology and the impact of thermal stress across the crystal-to-mesophase transition using temperature variation.

Main Results:

• The fabricated LC semiconductors exhibited characteristic FET properties with a notable carrier mobility.
• Thermal stress applied above the melting point of 8TNAT8 led to an irreversible decrease in FET mobility.
• Morphological changes in the LC semiconductor layer were observed after heat treatment, correlating with the mobility reduction.

Conclusions:

• 8TNAT8 functions as a viable organic semiconductor for FET applications.
• The thermal stability of the LC semiconductor layer is critical for maintaining device performance.
• Morphological degradation under thermal stress limits the operational stability of these LC FETs.