Carrier concentration-dependent interface engineering for high-performance zinc oxide piezoelectric device

Abstract

Piezoelectric semiconductor zinc oxide (ZnO) shows promising applications in many fields, however, its excellent piezoelectric performance is limited by the intrinsic screening effect. Forming p-n junction through interface engineering is an effective strategy to enhance its piezoelectric output, but the unclear regulation mechanism is a bottleneck in developing high-performance devices. In this work, the enhancement mechanism of interface engineering on the piezoelectric performance of ZnO nanorods (NRs) based devices is revealed from the perspective of carrier concentration. Both the theoretical and experimental results show that the piezoelectric output is significantly correlated with the carrier concentration, which is mainly attributed to the suppression of screening effect and the modulation of the device capacitance. After a reasonable matching design of carrier concentration, the piezoelectric potential of the ZnO NRs-based device is greatly enhanced by about 12 times. Apparently, these findings provide a fresh insight to further understand the enhancement mechanism of interface engineering on the electrical output of piezoelectric semiconductor devices, and provide effective support for the design of p-n junction piezoelectric devices.