Near-infrared and visible light dual-mode organic photodetectors

Zhaojue Lan; Yanlian Lei; Wing Kin Edward Chan; Shuming Chen; Dan Luo; Furong Zhu

doi:10.1126/sciadv.aaw8065

Near-infrared and visible light dual-mode organic photodetectors

Sci Adv. 2020 Jan 31;6(5):eaaw8065. doi: 10.1126/sciadv.aaw8065. eCollection 2020 Jan.

Authors

Zhaojue Lan^{1

2}, Yanlian Lei¹, Wing Kin Edward Chan¹, Shuming Chen², Dan Luo², Furong Zhu¹

Affiliations

¹ Department of Physics, Research Centre of Excellence for Organic Electronics, Institute of Advanced Materials, and State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
² Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.

Abstract

We report a dual-mode organic photodetector (OPD) that has a trilayer visible light absorber/optical spacer/near-infrared (NIR) light absorber configuration. In the presence of NIR light, photocurrent is produced in the NIR light-absorbing layer due to the trap-assisted charge injection at the organic/cathode interface at a reverse bias. In the presence of visible light, photocurrent is produced in the visible light-absorbing layer, enabled by the trap-assisted charge injection at the anode/organic interface at a forward bias. A high responsivity of >10 A/W is obtained in both short and long wavelengths. The dual-mode OPD exhibits an NIR light response operated at a reverse bias and a visible light response operated at a forward bias, with a high specific detectivity of ~10¹³ Jones in both NIR and visible light ranges. A bias-switchable spectral response OPD offers an attractive option for applications in environmental pollution detection, bioimaging process, wellness, and security monitoring in two distinct bands.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).