Temperature-Dependent Detectivity of Near-Infrared Organic Bulk Heterojunction Photodiodes

Authors

Zhenghui Wu, University of California, San DiegoFollow
Weichuan Yao, University of California, San Diego
Alexander E. London, University of Southern Mississippi
Jason D. Azoulay, University of Southern MississippiFollow
Tse Nga Ng, University of California, San DiegoFollow

Document Type

Article

Publication Date

12-17-2016

Department

Polymers and High Performance Materials

School

Mathematics and Natural Sciences

Abstract

Bulk heterojunction photodiodes are fabricated using a new donor–acceptor polymer with a near-infrared absorption edge at 1.2 μm, achieving a detectivity up to 10¹² Jones at a wavelength of 1 μm and an excellent linear dynamic range of 86 dB. The photodiode detectivity is maximized by operating at zero bias to suppress dark current, while a thin 175 nm active layer is used to facilitate charge collection without reverse bias. Analysis of the temperature dependence of the dark current and spectral response demonstrates a 2.8-fold increase in detectivity as the temperature was lowered from 44 to −12 °C, a relatively small change when compared to that of inorganic-based devices. The near-infrared photodiode shows a switching speed reaching up to 120 μs without an external bias. An application using our NIR photodiode to detect arterial pulses of a fingertip is demonstrated.

Publication Title

ACS Applied Materials & Interfaces

Volume

9

Issue

2

First Page

1654

Last Page

1660

Recommended Citation

Wu, Z., Yao, W., London, A. E., Azoulay, J. D., Ng, T. N. (2016). Temperature-Dependent Detectivity of Near-Infrared Organic Bulk Heterojunction Photodiodes. ACS Applied Materials & Interfaces, 9(2), 1654-1660.
Available at: https://aquila.usm.edu/fac_pubs/16656