Enhanced Humidity Sensitivity with Silicon Nanopillar Array by UV Light

Wei Li; Chao Ding; Yun Cai; Juyan Liu; Linlin Wang; Qingying Ren; Jie Xu

doi:10.3390/s18020660

Enhanced Humidity Sensitivity with Silicon Nanopillar Array by UV Light

Sensors (Basel). 2018 Feb 23;18(2):660. doi: 10.3390/s18020660.

Authors

Wei Li^{1

2}, Chao Ding³, Yun Cai⁴, Juyan Liu⁵, Linlin Wang⁶, Qingying Ren⁷, Jie Xu⁸

Affiliations

¹ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. Liw@njupt.edu.cn.
² State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China. Liw@njupt.edu.cn.
³ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. 1016020826@njupt.edu.cn.
⁴ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. 1017020831@njupt.edu.cn.
⁵ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. 1216022745@njupt.edu.cn.
⁶ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. 1217022824@njupt.edu.cn.
⁷ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. Rqy@njupt.edu.cn.
⁸ State-Province Joint Engineering Laboratory for RF Integration and Micropackaging, College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China. jiexu@njupt.edu.cn.

Abstract

The sensitivity of silicon nanopillar array for relative humidity (RH) with UV illumination was investigated in this work. The silicon nanopillar array was prepared by nanosphere lithography. Electrical measurements were performed on its sensing performance with and without UV irradiation. It was found that UV light improved the humidity sensitivity with different UV light wavelengths and power. The sensor response and recovery time were reduced. Furthermore, the turn-on threshold voltage and the operating voltage both decreased. These sensing characteristics can mainly be attributed to the electron-hole pairs generated by UV light. These electron-hole pairs promote the adsorption and desorption processes. The results indicate that silicon nanopillar array materials with UV irradiation might be competitive as novel sensing materials for fabricating humidity sensors with high performances.

Keywords: UV light; humidity sensing; silicon nanopillar.