Contribution of Sub-Gap States to Broadband Infrared Response in Organic Bulk Heterojunctions

Authors

Ning Li, University of California San DiegoFollow
Insun Park, Samsung Advanced Institute of Technology
Jarrett H. Vella, Air Force Research LaboratoryFollow
Soong Ju Oh, Korea University
Jason D. Azoulay, University of Southern MississippiFollow
Dong-Seok Leem, Samsung Advanced Institute of TechnologyFollow
Tse Nga Ng, University of California San DiegoFollow

Document Type

Article

Publication Date

11-17-2022

School

Polymer Science and Engineering

Abstract

This work studied a series of infrared detectors comprised of organic bulk heterojunctions to explain the origin of their broadband spectral response from the visible to the infrared spanning 1 to 8 μm and the transition from photonic to bolometric operation. Through comparisons of the detector current and the sub-bandgap density of states, the mid- and long-wave infrared response was attributed to charge trap-and-release processes that impact thermal charge generation and the activation energy of charge mobility. We further demonstrate how the sub-bandgap characteristics, mobility activation energy, and effective bandgap are key design parameters for controlling the device temperature coefficient of resistance, which reached up to −7%/K, better than other thin-film materials such as amorphous silicon and vanadium oxide.

Publication Title

ACS Applied Materials & Interfaces

Volume

14

Issue

47

First Page

53111

Last Page

53119

Recommended Citation

Li, N., Park, I., Vella, J. H., Oh, S., Azoulay, J. D., Leem, D., Ng, T. (2022). Contribution of Sub-Gap States to Broadband Infrared Response in Organic Bulk Heterojunctions. ACS Applied Materials & Interfaces, 14(47), 53111-53119.
Available at: https://aquila.usm.edu/fac_pubs/20527