Controlling exciton dynamics at organic semiconductor interfaces is of fundamental and practical importance, for example, in an organic field‐effect transistor (OFET) photomemory that possesses multifunctional applications. Moreover, the intrinsic properties of embedded charge storage layer may limit the device performances. This report introduces a concept of tunneling‐effect‐assisted interfacial charge trapping and takes full benefit of inherent rich surface traps of dielectrics for OFET photomemory. By controlling the thickness of barrier interlayer between active channel and dielectric, the trapped charge injection and dissipation can be regulated precisely. As a result, excellent transistor characteristics display an inconspicuous threshold voltage shift and hysteresis in dark or light exposure, while the same device can exhibit an outstanding memory behavior upon a gate bias pulse in bright situation. Without any additional materials handling such as photoactive charge storage layer into the construction, it can promise a low‐cost, facile, and versatile device fabrication.

In this work, a novel thermoresponsive switching transistor is developed through the rational design of active materials based on the typical field-effect transistor (FET) device configuration, where the active material is composed of a blend of a thermal expansion polymer and a polymeric semiconductor. Herein, polyethylene (PE) is employed as the thermal expansion polymer because of its high volume expansion coefficient near its melting point (90–130 °C), which similarly corresponds to the overheating point that would cause damage or cause fire in the devices. It is revealed that owing to the thermistor property of PE, the FET characteristics of the derived device will be largely decreased at high temperatures (100–120 °C). It is because the high volume expansion of PE at such high temperature (near its Tm) effectively increases the distance of the crystalline domains of poly(3-hexylthiophene-2,5-diyl) to result in a great inhibition of current. Besides, the performance of this device will recover back to its original value after cooling from 120 to 30 °C owing to the volume contraction of PE. The reversible FET characteristics with temperature manifest the good thermal sensitivity of the PE-based device. Our results demonstrate a facile and promising approach for the development of next-generation overheating shutdown switches for electrical circuits.