Author ORCID Identifier
0009-0004-8138-0187
Document Type
Dissertation
Date of Award
5-31-2025
Degree Name
Doctor of Philosophy in Electrical Engineering - (Ph.D.)
Department
Electrical and Computer Engineering
First Advisor
Dong Kyun Ko
Second Advisor
Haim Grebel
Third Advisor
Xuan Liu
Fourth Advisor
Ken Keunhyuk Ahn
Fifth Advisor
Yeonwoong Jung
Abstract
Reducing the size, weight, power consumption, and cost (SWaP-C) of infrared detectors could make infrared sensing more widely accessible. In the critical mid-wavelength infrared (MWIR) spectral range of 3-5 gm, commercially available detectors are limited by the high costs associated with epitaxial growth and hybridization, as well as the need for cryogenic cooling. These factors restrict their use to defense and space applications.
Colloidal quantum dots present a promising material for overcoming these challenges, with wafer-scale monolithic integration and Auger suppression being the key material capabilities to minimize the sensor's SWaP-C. Infrared sensors based on colloidal quantum dots have been studied for decades, with much research focused on utilizing interband transitions in these quantum-confined nanostructures. However, more unique photophysical properties can be exploited by tapping into intraband (intersubband) transitions within the conduction or valence levels. This dissertation explores the progress, challenges, and opportunities of MWIR sensor made from silver selenide (Ag2Se) intraband colloidal quantum dots, a heavy metal-free material with a potential for widespread adoption in consumer and industrial sectors.
In addition to intraband colloidal quantum dots, polycrystalline lead selenide (PbSe) offers another promising option. PbSe is an 80-year-old technology that has reemerged in recent years, due to its advantageous low manufacturing cost and Auger-suppression properties. This dissertation also explores a colloidal route to fabricating PbSe MWIR sensors. The resulting solution-based fabrication can be applied to high-resolution inkjet printing or large-area microscreen printing, serving as a critical step toward enabling the additive manufacturing of mid-infrared sensor arrays in the future.
Recommended Citation
Al Mahfuz, Mohammad Mostafa, "Colloidal quantum dots: a path toward making mid-wave infrared sensing a ubiquitous technology" (2025). Dissertations. 1828.
https://digitalcommons.njit.edu/dissertations/1828
Included in
Electronic Devices and Semiconductor Manufacturing Commons, Nanoscience and Nanotechnology Commons, Nanotechnology Fabrication Commons, Semiconductor and Optical Materials Commons
