Abstract

Controlling and modulating terahertz signals is of fundamental importance to allow systems level applications. We demonstrate an innovative approach for controlling the propagation properties of terahertz (THz) radiation, through use of both the excitation optical wavelength (colour) and intensity. We accomplish this using two-dimensional (2D) layered hybrid trihalide perovskites that are deposited onto silicon substrates. The absorption properties of these materials in the visible range can be tuned by changing the number of inorganic atomic layers in between the organic cation layers. Optical absorption in 2D perovskites occurs over a broad spectral range above the bandgap, resulting in free carrier generation, as well as over a narrow spectral range near the bandedge due to exciton formation. We find that only the latter contribution gives rise to photo-induced THz absorption. By patterning multiple 2D perovskites with different optical absorption properties onto a single device, we demonstrate both colour selective modulation and focusing of THz radiation. These findings open new directions for creating active THz devices.

Details

Title
Colour selective control of terahertz radiation using two-dimensional hybrid organic inorganic lead-trihalide perovskites
Author
Chanana, Ashish 1   VIAFID ORCID Logo  ; Zhai, Yaxin 2 ; Baniya, Sangita 2 ; Zhang, Chuang 3   VIAFID ORCID Logo  ; Vardeny, Z Valy 2 ; Nahata, Ajay 1 

 Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, USA 
 Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA 
 Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA; Institute of Chemistry, Chinese Academy of Sciences, Beijing, China 
Pages
1-8
Publication year
2017
Publication date
Nov 2017
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1960508707
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.