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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...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2018
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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. |
format | Online Article Text |
id | pubmed-6165075 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
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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