Influence of carrier concentration on piezoelectric potential in a bent ZnO nanorod

The influence of carriers on the piezoelectric potential in a bent ZnO nanorod is investigated using finite difference method. The distributions of carriers and the electrical potential in the nanorod are obtained. The results shows that the positive piezoelectric potential in stretched side of the bent nanorod is significantly screened by the carriers and the negative potential in compressed side is well preserved when considering a moderate carrier concentration of 1×1017 cm−3. The calculation results agree with the experimental results that only negative pulses are observed in the nanogenerator experiment using the as-grown ZnO nanorods. Further investigation shows that when the carrier concentration is 1×1018 cm−3, the piezoelectric potential in the nanorod is almost completely screened by the redistributed carriers.