Control of photoelectron kinetics to improve performance of quantum dot-based optoelectronic devices

Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Nanoscale Science and Engineering


Nanoscale Sciences

Content Description

1 online resource (xii, 101 pages) : illustrations.

Dissertation/Thesis Chair

Serge Oktyabrsky

Committee Members

Vincent LaBella, Hassaram Bakhru, Harry Efstathiadis, Gopal Pethuraja


QDIP, QDSC, Optoelectronic devices, Quantum dots, Infrared detectors, Photoelectrons, Optical detectors, Semiconductor doping

Subject Categories

Nanoscience and Nanotechnology


The topic of my dissertation is to find technological methods to control photocarrier kinetics in quantum dot infrared photodetectors and quantum dot solar cells. Quantum dot infrared photodetectors can be used in various applications like night infrared vision, search and rescue, space surveillance and medical diagnostics. However photoconductive detectors suffer from short photocarrier lifetime, that drastically reduces the photocurrent and limits the operation temperature. This also affects the responsivity and detectivity of the detector. Suppression of photoelectron capture can be realized by adjusting the potential barriers around the quantum dots, which spatially separates the localized states from the continuum. Potential barriers are formed when electrons populating the dots are taken from nearby doped layers (modulation interdot doping). For the first part of my dissertation, I will be focusing on the effect of tuning the electrostatic potential barrier by four means: (1) by changing the number of electrons in a quantum dot; (2) by varying the spacing between the quantum dot planes; (3) by modifying shape of quantum dots (4) by varying the number of electrons in quantum dot by complex bipolar doping (with acceptor doping directly into the dots and donors between the QD layers). These approaches suppress the photoelectron capture and improve the performance of the detectors.


Requested ProQuest takedown; no end date

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