Abstract Some piezoelectric materials, such as zinc oxide, are semiconductors simultaneously. Usually, the semiconductive property of these materials is omitted in the study of piezoelectric characteristics. However, due to the small sizes of some piezoelectric devices, such as nanogenerators, the semiconductive property may have an appreciable impact on the wave motion characteristics and potential output. In this paper, we study the influence of semiconductive property for the improvement of nanogernerators through the propagation of shear-horizontal waves in a piezoelectric semiconductor plate of 6 mm class crystals by using wave mode approach. Some interesting results are observed from the points of both mechanical and electrical views. Mechanically, the semiconductive property will reduce the frequencies of waves (decrease the kinetic energy of waves), and cause new size-dependent wave modes due to the drift of electrons and holes. Meanwhile, a size-dependent acoustic loss is generated, where the acoustic loss becomes greater when the size gets smaller. Electrically, by comparing the magnitudes and distributions of potential between the cases with and without semiconduction, it is presented that energy can be harvested not only when the deformations are generated but also when the deformations are recovering. Further, the potential output in piezoelectric semiconductor can be improved by increasing strain and reducing conductivity. These results are useful for the design of piezoelectric semiconductor devices. They are also good corrections to the theoretical analyses of some piezoelectric devices in which semiconductive property is omitted, especially for the devices with small sizes. Graphical abstract The influences of semiconductive effect on the wave motion and potential output of piezoelectric semiconductor nanoplate were studied. The dispersion curves for different plate thicknesses were obtained, along with detailed distributions of displacements, electric potential, and concentrations of holes and electrons. Results show semiconductive property will result in size-dependent acoustic energy loss. Meanwhile, new size-dependent wave modes appear whose predominant energy is caused by holes and electrons with negligible mechanical energy. On the other hand, the semiconductive property will also reduce potential output significantly, and the detailed mechanical and electrical influence factors on piezoelectric potential are studied for the improvement of the potential output. This work studied a steady state process of wave propagating in nanoplate involving both electron and hole using a fully coupled constitutive equation, which is a more realistic picture for revealing intrinsic characteristics of semiconductive piezoelectric materials. fx1 Highlights • Displacement, electric potential and carrier concentration profiles were obtained. • Semiconductive effect will cause size-dependent acoustic energy loss. • New wave modes appear whose predominant energy is caused by holes and electrons. • Potential magnitudes can be improved by increasing strain and reducing conductivity. • Energy can be harvested in the recovery of deformation as well. [ABSTRACT FROM AUTHOR]