Article Title

Enhanced performance of GaN nanobelt-based photodetectors by means of piezotronic effects

Authors

Ruomeng Yu, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA
Caofeng Pan, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, China
Youfan Hu, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA
Lin Li, School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
Hongfei Liu, Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602, Singapore
Wei Liu, School of Electrical and Electronic Engineering, Luminous! Center of Excellence for Semiconductor Lighting and Display, Nanyang Technology University, Singapore 639798, Singapore
Soojin Chua, Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602, Singapore
Dongzhi Chi, Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602, Singapore
Zhong Lin Wang, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, China

Keywords

GaN nanobelts, Schottky contact, piezotronics, photodetector

Abstract

GaN ultraviolet (UV) photodetectors (PDs) have attracted tremendous attention due to their chemical stability in harsh environments. Although Schottkycontacted GaN-based UV PDs have been implemented with better performance than that of ohmic contacts, it remains unknown how the barrier height at local Schottky contacts controls the sensors’ performance. In this work, the piezotronic effect was employed to tune the Schottky barrier height (SBH) at local contacts and hence enhance the performances of Schottky-contacted metal–semiconductor– metal (MSM) structured GaN nanobelt (NB)-based PDs. In general, the response level of the PDs was obviously enhanced by the piezotronic effect when applying a strain on devices. The responsivity of the PD was increased by 18%, and the sensitivity was enhanced by from 22% to 31%, when illuminated by a 325 nm laser with light intensity ranging from 12 to 2 W/cm2. Carefully studying the mechanism using band structure diagrams reveals that the observed enhancement of the PD performance resulted from the change in SBH caused by external strain as well as light intensity. Using piezotronic effects thus provides a practical way to enhance the performance of PDs made not only of GaN, but also other wurtzite and zinc blende family materials.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-013-0354-2

Publisher

Tsinghua University Press

Recommended Citation

Ruomeng Yu,Caofeng Pan,Youfan Hu,Lin Li,Hongfei Liu,Wei Liu,Soojin Chua,Dongzhi Chi,Zhong Lin Wang, Enhanced performance of GaN nanobelt-based photodetectors by means of piezotronic effects. NanoRes.2013, 6(10): 758–766