The Graphene-Based Transistor with Dual Modifications through Electrostatic and Strain Effects

Two-dimensional (2D) materials, such as graphene, are sensitive to electrostatic and strain effects because their band structure significantly depends on the carrier density and carbon bond lengths and angles. Leveraging this principle, graphene-based transistors offer potential advantages for designing next-generation electronic devices through electrostatic and strain tunability. However, existing graphene-based transistors rarely exhibit variations in transport properties induced by strain. In this study, we fabricated a transistor composed of graphene and PbZr0.52Ti0.48O3 (PZT), where graphene served as the conductive channel and PZT as the field gate layer. Experimental observations revealed that applying voltage to PZT resulted in a hysteresis characteristic in the graphene transport curve, and the current curve I-ds-V-g exhibited distinct dual loops, one resembling a rectangle and the other resembling a butterfly curve. These effects arise from the combined influences of the ferroelectricity and piezoelectricity of PZT. Consequently, the conductivity of graphene can be tuned through carrier accumulation and depletion and continuous in-plane stress. This discovery enriches the design strategy for 2D-based electronic devices with multiple external field modulations.