Crucial role of interfacial thermal dissipation in the operational stability of organic field-effect transistors

The operational stability becomes a key issue affecting the commercialization for organic field-effect transistors (OFETs). It is widely recognized to be closely related to the defects and traps at the interface between dielectric and organic semiconductors, but this understanding does not always effectively address operational instability, implying that the factors influencing the operational stability have not been fully understood. Here, we reveal that the self-heating effect is another crucial factor in operational stability. By using hexagonal boron nitride (hBN) to assist interfacial thermal dissipation, the dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) FETs exhibit high mobility of 14.18 cm² V⁻¹ s⁻¹ and saturated power density up to 1.8 × 10⁴ W cm⁻². The OFET can operate at a power density of 1.06 × 10⁴ W cm⁻² for 30,000 s with negligible performance degradation, showing excellent operational stability under high power density. This work deepens the understanding on operational stability and develops an effective way for ultrahigh stable devices.