%AWu, Zhenghui [Department of Electrical and Computer Engineering University of California San Diego 9500 Gilman Drive La Jolla CA 92093‐0407 USA]%AZhai, Yichen [Department of Electrical and Computer Engineering University of California San Diego 9500 Gilman Drive La Jolla CA 92093‐0407 USA]%AYao, Weichuan [Department of Electrical and Computer Engineering University of California San Diego 9500 Gilman Drive La Jolla CA 92093‐0407 USA]%AEedugurala, Naresh [School of Polymer Science and Engineering University of Southern Mississippi 118 College Drive #5050 Hattiesburg MS 39406 USA]%AZhang, Song [School of Polymer Science and Engineering University of Southern Mississippi 118 College Drive #5050 Hattiesburg MS 39406 USA]%AHuang, Lifeng [School of Polymer Science and Engineering University of Southern Mississippi 118 College Drive #5050 Hattiesburg MS 39406 USA]%AGu, Xiaodan [School of Polymer Science and Engineering University of Southern Mississippi 118 College Drive #5050 Hattiesburg MS 39406 USA]%AAzoulay, Jason [School of Polymer Science and Engineering University of Southern Mississippi 118 College Drive #5050 Hattiesburg MS 39406 USA]%ANg, Tse [Department of Electrical and Computer Engineering University of California San Diego 9500 Gilman Drive La Jolla CA 92093‐0407 USA]%BJournal Name: Advanced Functional Materials; Journal Volume: 28; Journal Issue: 50; Related Information: CHORUS Timestamp: 2023-09-14 22:45:02 %D2018%IWiley Blackwell (John Wiley & Sons) %JJournal Name: Advanced Functional Materials; Journal Volume: 28; Journal Issue: 50; Related Information: CHORUS Timestamp: 2023-09-14 22:45:02 %K %MOSTI ID: 10078118 %PMedium: X %TThe Role of Dielectric Screening in Organic Shortwave Infrared Photodiodes for Spectroscopic Image Sensing %XAbstract

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.

%0Journal Article