The Role of Dielectric Screening in Organic Shortwave Infrared Photodiodes for Spectroscopic Image Sensing
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 16, 2018
- Source ID
- 10.1002/adfm.201805738
Entities
People
- Jason D Azoulay
- Lifeng Huang
- Naresh Eedugurala
- Song Zhang
- Tse Nga Ng
- Weichuan Yao
- Xiaodan Gu
- Yichen Zhai
- Zhenghui Wu
Organizations
- Air Force Office of Scientific Research
- American Chemical Society Petroleum Research Fund
- National Science Foundation
- United States Army Research Laboratory
- University of California, San Diego
- University of Southern Mississippi