Charge-Generating Mode Control in High-Performance Transparent Flexible Piezoelectric Nanogenerators

Authors

  • Hyun-Kyu Park,

    1. School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon 440–746, Republic of Korea
    Search for more papers by this author
  • Keun Young Lee,

    1. School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon 440–746, Republic of Korea
    Search for more papers by this author
  • Ju-Seok Seo,

    1. School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon 440–746, Republic of Korea
    Search for more papers by this author
  • Jin-A Jeong,

    1. Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi 446–701, Republic of Korea
    Search for more papers by this author
  • Han-Ki Kim,

    1. Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi 446–701, Republic of Korea
    Search for more papers by this author
  • Dukhyun Choi,

    Corresponding author
    1. Department of Mechanical Engineering, Kyung Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi 446–701, Republic of Korea
    • Department of Mechanical Engineering, Kyung Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi 446–701, Republic of Korea.
    Search for more papers by this author
  • Sang-Woo Kim

    Corresponding author
    1. School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon 440–746, Republic of Korea
    • School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Center for Human Interface Nanotechnology (HINT), Sungkyunkwan University, Suwon 440–746, Republic of Korea
    Search for more papers by this author

Abstract

In this work, we demonstrate the mode transition of charge generation between direct-current (DC) and alternating-current (AC) from transparent flexible (TF) piezoelectric nanogenerators (NGs), which is dependent solely on the morphology of zinc oxide (ZnO) nanorods without any use of an AC/DC converter. Tilted ZnO nanorods grown on a relatively low-density seed layer generate DC-type piezoelectric charges under a pushing load, whereas vertically aligned ZnO nanorods on a relatively high-density seed layer create AC-type charge generation. The mechanism for the geometry-induced mode transition is proposed and characterized. We also examine the output performance of TF-NGs which employ an indium zinc tin oxide (IZTO) film as a TF electrode. It is demonstrated that an IZTO film has improved electrical, optical, and mechanical properties, in comparison with an indium tin oxide (ITO) film. Enhanced output charge generation is observed from IZTO-based TF-NGs when TF-NGs composed of only ITO electrodes are compared. This is attributed to the higher Schottky barrier and the lower series resistance of the IZTO-based TF-NGs. Thus, by using IZTO, we can expect TF-NGs with superior mechanical durability and power generating performance.

Ancillary