Schottky photodiodes based on mid-wavelength infrared intraband colloidal quantum dots - surface ligand and metal contact studies

Authors

Mohammad M. Al Mahfuz, Newark College of Engineering
Junsung Park, Newark College of Engineering
Rock Huebner, Newark College of Engineering
Sunghwan Lee, Purdue Polytechnic Institute
Dong Kyun Ko, Newark College of Engineering

Document Type

Article

Publication Date

5-22-2023

Abstract

There is an emergent need for low-cost, uncooled detectors operating in the mid-wavelength infrared. Here, we report the first Schottky junction diode that utilizes intraband Ag2Se colloidal quantum dots as mid-wavelength infrared absorbers. These inexpensive, solution-processed Schottky devices exhibit orders-of-magnitude suppression of dark current compared to the photoconductors, while providing a greater fabrication simplicity compared to the barrier or p-n heterojunction devices. We highlight our findings on the role of the capping ligand in the detector performance parameters and discuss our metal contact studies to form rectifying junctions to the colloidal quantum dot films. The optimized Schottky devices show a favorable infrared responsivity of 0.1 A W⁻¹ and an uncooled specific detectivity of 10⁷ Jones. We also identify the present limitation of the device (1/f noise) and discuss potential paths toward future improvements.

Identifier

85161542053 (Scopus)

Publication Title

Journal of Materials Chemistry C

External Full Text Location

https://doi.org/10.1039/d3tc00648d

e-ISSN

20507534

ISSN

20507526

First Page

7714

Last Page

7721

Issue

23

Volume

11

Grant

N68335-22-C-0079

Recommended Citation

Al Mahfuz, Mohammad M.; Park, Junsung; Huebner, Rock; Lee, Sunghwan; and Ko, Dong Kyun, "Schottky photodiodes based on mid-wavelength infrared intraband colloidal quantum dots - surface ligand and metal contact studies" (2023). Faculty Publications. 1721.
https://digitalcommons.njit.edu/fac_pubs/1721