Fig. 4: Flexoelectronic effect in p-Si micropillars.

a The measurement system consists of the semiconductor test system, two three-dimensional displacement stages and a dynamometer. b I–V characteristics of p-Si were tested by applying bias voltages ranging from −1 to 1 V under external stress. c Dependence of the current change on the external pressure under forward and reverse bias. d The ratio of current to initial current under forward and reverse bias corresponds to the dependence of the force gradient. e, f Simulation analysis of Si micropillars under an external loading force. Strain distribution e in the Si single crystal and corresponding flexoelectric polarization distribution f in the Si single crystal under applied external pressure. The arrows in f indicate the polarization direction.