The Role of Dielectric Screening in Organic Shortwave Infrared Photodiodes for Spectroscopic Image Sensing
Document Type
Article
Publication Date
12-12-2018
Department
Polymers and High Performance Materials
Abstract
This work examines an additive approach that increases dielectric screening to overcome performance challenges in organic shortwave infrared (SWIR) photodiodes. The role of the high‐permittivity additive, camphoric anhydride, in the exciton dissociation and charge collection processes is revealed through measurements of transient photoconductivity and electrochemical impedance. Dielectric screening reduces the exciton binding energy to increase exciton dissociation efficiency and lowers trap‐assisted recombination loss, in the absence of any morphological changes for two polymer variants. In the best devices, the peak internal quantum efficiency at 1100 nm is increased up to 66%, and the photoresponse extends to 1400 nm. The SWIR photodiodes are integrated into a 4 × 4 pixel imager to demonstrate tissue differentiation and estimate the fat‐to‐muscle ratio through noninvasive spectroscopic analysis.
Publication Title
Advanced Functional Materials
Volume
28
Issue
50
Recommended Citation
Wu, Z.,
Zhai, Y.,
Yao, W.,
Eedugurala, N.,
Zhang, S.,
Huang, L.,
Gu, X.,
Azoulay, J. D.,
Ng, T. N.
(2018). The Role of Dielectric Screening in Organic Shortwave Infrared Photodiodes for Spectroscopic Image Sensing. Advanced Functional Materials, 28(50).
Available at: https://aquila.usm.edu/fac_pubs/15621
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