Pyroelectric effect mediated infrared photoresponse in Bi₂Te₃/Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ optothermal ferroelectric...

The responses of material properties to multi-field stimulation are often exploited to construct new types of multi-functional devices. Here, we demonstrate electrical, optical and thermal modulation of the electronic properties of optothermal ferroelectric field-effect transistors (FeFETs) which are fabricated by growing Bi₂Te₃ films on (111)-oriented 0.71Pb(Mg_1/3Nb_2/3)O₃-0.29PbTiO ₃ (PMN-PT) ferroelectric single-crystal substrates. Using the electric field to switch the polarization direction of PMN-PT, the carrier density and resistance of Bi₂Te₃ films are in situ, reversibly, and nonvolatilely modulated via the ferroelectric field effect. Moreover, through infrared light illumination on the bottom of PMN-PT substrates, the resistance of Bi₂Te₃ films in two polarization states could be further modulated, which is ascribed to the decreased polarization intensity at higher temperature due to the pyroelectric effect. Taking advantage of these two effects, the Bi₂Te₃/PMN-PT optothermal FeFETs exhibit multiple responses to optical and electric field stimulation at room temperature. Our work provides a strategy to design optoelectronic devices with both photodetector and memory functionalities.