Understanding the Enhancement Mechanism of ZnO Nanorod-based Piezoelectric Devices through Surface Engineering
Hongrui Zhang, Guo Tian, Da Xiong, Tao Yang, Shen Zhong, Long Jin, Boling Lan, Lin Deng, Shenglong Wang, Yue Sun, Weiqing Yang, Weili Deng
Abstract
ZnO is a typical piezoelectric semiconductor, and enhancing the piezoelectric output of ZnO-based devices is essential for their efficient applications. Surface engineering is an effective strategy to improve the piezoelectric output of ZnO-based devices, but its unclear regulation mechanism leads to a lack of reasonable guidance for device design. In this work, the regulation effect of the barrier layer in ZnO-based piezoelectric devices is systematically investigated from the carrier perspective through surface engineering, resulting in a significant improvement (nearly 10-fold) in the output performance of piezoelectric devices. The regulation mechanism of the ZnO–Cu2O p–n heterojunction devices on piezoelectric output is revealed in terms of built-in electric field, depletion layer width, and junction capacitance. These findings facilitate further insight into the enhancement mechanism of the piezoelectric output of ZnO-based devices and provide reasonable ideas for efficient device design.