Effects of edge and interior stresses on electrical behaviors of piezoelectric semiconductor films

We study electrical behaviors of a thin piezoelectric semiconductor film under edge stress or interior local stress. The theory of piezoelectricity with coupling to the diffusion-drift theory of semiconductors is used. It is reduced to a two-dimensional theory for the extension of thin piezoelectric semiconductor films. The two-dimensional equations are solved using COMSOL, a numerical analysis software. An n-type MoS2 monolayer is analyzed in detail. The electric potential and electron concentration distributions under edge stresses are calculated. The effects of the stress amplitude, the doping level of electrons and the in-plane material orientation are examined. The current-voltage relations with three edge electrodes under local stresses are also presented. It is shown that local stresses produce local potential barriers and wells which prohibit or allow currents depending on the stress level.