High Optical Response of Niobium-Doped WSe₂-Layered Crystals

Hung-Pin Hsu; Der-Yuh Lin; Jhin-Jhong Jheng; Pin-Cheng Lin; Tsung-Shine Ko

doi:10.3390/ma12071161

High Optical Response of Niobium-Doped WSe₂-Layered Crystals

Materials (Basel). 2019 Apr 10;12(7):1161. doi: 10.3390/ma12071161.

Authors

Hung-Pin Hsu¹, Der-Yuh Lin², Jhin-Jhong Jheng³, Pin-Cheng Lin⁴, Tsung-Shine Ko⁵

Affiliations

¹ Department of Electronic Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan. hphsu@mail.mcut.edu.tw.
² Department of Electronic Engineering, National Changhua University of Education, Changhua 50074, Taiwan. dylin@cc.ncue.edu.tw.
³ Department of Electronic Engineering, National Changhua University of Education, Changhua 50074, Taiwan. M0453002@mail.ncue.edu.tw.
⁴ Department of Electronic Engineering, National Changhua University of Education, Changhua 50074, Taiwan. M0653013@mail.ncue.edu.tw.
⁵ Department of Electronic Engineering, National Changhua University of Education, Changhua 50074, Taiwan. tsko@cc.ncue.edu.tw.

Abstract

The optical properties of WSe₂-layered crystals doped with 0.5% niobium (Nb) grown by the chemical vapor transport method were characterized by piezoreflectance (PzR), photoconductivity (PC) spectroscopy, frequency-dependent photocurrent, and time-resolved photoresponse. With the incorporation of 0.5% Nb, the WSe₂ crystal showed slight blue shifts in the near band edge excitonic transitions and exhibited strongly enhanced photoresponsivity. Frequency-dependent photocurrent and time-resolved photoresponse were measured to explore the kinetic decay processes of carriers. Our results show the potential application of layered crystals for photodetection devices based on Nb-doped WSe₂-layered crystals.

Keywords: 2D chalcogenides; photoconductivity; photoresponse.

Grants and funding

MOST 107-2221-E-131-032 and MOST 107-2112-M-018-002/Ministry of Science and Technology, Taiwan