Equilibrium Potential of Free Charge Carriers in a Bent Piezoelectric Semiconductive Nanowire

We have investigated the behavior of free charge carriers in a bent piezoelectric semiconductive nanowire under thermodynamic equilibrium conditions. For a laterally bent n-type ZnO nanowire, with the stretched side exhibiting positive piezoelectric potential and the compressed side negative piezoelectric potential, the conduction band electrons tend to accumulate at the positive side. The positive side is thus partially screened by free charge carriers while the negative side of the piezoelectric potential preserves as long as the donor concentration is not too high. For a typical ZnO nanowire with diameter 50 nm, length 600 nm, donor concentration N D = 1 × 1017 cm−3 under a bending force of 80 nN, the potential in the positive side is