Dynamic Electronic Doping for Correlated Oxides by a Triboelectric Nanogenerator

The metal-insulator transition of vanadium dioxide (VO2 ) is exceptionally sensitive to charge density and electron orbital occupancy. Thus three-terminal field-effect transistors with VO2 channels are widely adopted to control the phase transition by external gating voltage. However, current leakage, electrical breakdown, or interfacial electrochemical reactions may be inevitable if conventional solid dielectrics or ionic-liquid layers are used, which possibly induce Joule heating or doping in the VO2 layer and make the voltage-controlled phase transition more complex. Here, a triboelectric nanogenerator (TENG) and a VO2 film are combined for a novel TENG-VO2 device, which can overcome the abovementioned challenges and achieve electron-doping-induced phase modulation. By taking advantage of the TENG structure, electrons can be induced in the VO2 channel and thus adjust the electronic states of the VO2 , simultaneously. The modulation degree of the VO2 resistance depends on the temperature, and the major variation occurs when the temperature is in the phase-transition region. The accumulation of electrons in the VO2 channel also is simulated by finite element analysis, and the electron doping mechanism is verified by theoretical calculations. The results provide a promising approach to develop a novel type of tribotronic transistor and new electronic doping technology.