I-V characteristics of a piezoelectric semiconductor nanofiber under local tensile/compressive stress

We study the electrical behavior of a piezoelectric semiconductor fiber under local extensional or compressive stress and an applied voltage. A numerical analysis based on a one-dimensional phenomenological model is performed. The current-voltage relation is obtained. It is found that when the applied voltage is below a stress-dependent critical value, no current can flow through the fiber in either direction. When the voltage is above the critical voltage, currents can flow in one direction but not the other. When the voltage is above a second critical value, currents can flow in both directions. Thus, the local stress acts like a switch, which can turn the currents on and off in one or both directions. This provides a basic means for mechanically manipulating the electrical behavior of piezoelectric semiconductor fibers and thus serves as a fundamental element of piezotronics.