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Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons

Control of quantum-dot (QD) surface chemistry offers a direct approach for the tuning of charge-carrier dynamics in photoconductors based on strongly coupled QD solids. We investigate the effects of altering the surface chemistry of PbS QDs in such QD solids via ligand exchange using 3-mercaptopropi...

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Autores principales: Maulu, Alberto, Navarro-Arenas, Juan, Rodríguez-Cantó, Pedro J., Sánchez-Royo, Juan F., Abargues, Rafael, Suárez, Isaac, Martínez-Pastor, Juan P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165075/
https://www.ncbi.nlm.nih.gov/pubmed/30200230
http://dx.doi.org/10.3390/nano8090677
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author Maulu, Alberto
Navarro-Arenas, Juan
Rodríguez-Cantó, Pedro J.
Sánchez-Royo, Juan F.
Abargues, Rafael
Suárez, Isaac
Martínez-Pastor, Juan P.
author_facet Maulu, Alberto
Navarro-Arenas, Juan
Rodríguez-Cantó, Pedro J.
Sánchez-Royo, Juan F.
Abargues, Rafael
Suárez, Isaac
Martínez-Pastor, Juan P.
author_sort Maulu, Alberto
collection PubMed
description Control of quantum-dot (QD) surface chemistry offers a direct approach for the tuning of charge-carrier dynamics in photoconductors based on strongly coupled QD solids. We investigate the effects of altering the surface chemistry of PbS QDs in such QD solids via ligand exchange using 3-mercaptopropionic acid (MPA) and tetrabutylammonium iodide (TBAI). The roll-to-roll compatible doctor-blade technique was used for the fabrication of the QD solid films as the photoactive component in photoconductors and field-effect phototransistors. The ligand exchange of the QD solid film with MPA yields superior device performance with higher photosensitivity and detectivity, which is due to less dark current and lower noise level as compared to ligand exchange with TBAI. In both cases, the mechanism responsible for photoconductivity is related to trap sensitization of the QD solid, in which traps are responsible of high photoconductive gain values, but slow response times under very low incident optical power (<1 pW). At medium–high incident optical powers (>100 pW), where traps are filled, both MPA- and TBAI-treated photodevices exhibit similar behavior, characterized by lower responsivity and faster response time, as limited by the mobility in the QD solid.
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spelling pubmed-61650752018-10-10 Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons Maulu, Alberto Navarro-Arenas, Juan Rodríguez-Cantó, Pedro J. Sánchez-Royo, Juan F. Abargues, Rafael Suárez, Isaac Martínez-Pastor, Juan P. Nanomaterials (Basel) Article Control of quantum-dot (QD) surface chemistry offers a direct approach for the tuning of charge-carrier dynamics in photoconductors based on strongly coupled QD solids. We investigate the effects of altering the surface chemistry of PbS QDs in such QD solids via ligand exchange using 3-mercaptopropionic acid (MPA) and tetrabutylammonium iodide (TBAI). The roll-to-roll compatible doctor-blade technique was used for the fabrication of the QD solid films as the photoactive component in photoconductors and field-effect phototransistors. The ligand exchange of the QD solid film with MPA yields superior device performance with higher photosensitivity and detectivity, which is due to less dark current and lower noise level as compared to ligand exchange with TBAI. In both cases, the mechanism responsible for photoconductivity is related to trap sensitization of the QD solid, in which traps are responsible of high photoconductive gain values, but slow response times under very low incident optical power (<1 pW). At medium–high incident optical powers (>100 pW), where traps are filled, both MPA- and TBAI-treated photodevices exhibit similar behavior, characterized by lower responsivity and faster response time, as limited by the mobility in the QD solid. MDPI 2018-08-30 /pmc/articles/PMC6165075/ /pubmed/30200230 http://dx.doi.org/10.3390/nano8090677 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Maulu, Alberto
Navarro-Arenas, Juan
Rodríguez-Cantó, Pedro J.
Sánchez-Royo, Juan F.
Abargues, Rafael
Suárez, Isaac
Martínez-Pastor, Juan P.
Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons
title Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons
title_full Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons
title_fullStr Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons
title_full_unstemmed Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons
title_short Charge Transport in Trap-Sensitized Infrared PbS Quantum-Dot-Based Photoconductors: Pros and Cons
title_sort charge transport in trap-sensitized infrared pbs quantum-dot-based photoconductors: pros and cons
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165075/
https://www.ncbi.nlm.nih.gov/pubmed/30200230
http://dx.doi.org/10.3390/nano8090677
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