A p-type PbS quantum dot ink with improved stability for solution processable optoelectronics

Ahmed, Fiaz; Dunlap, John H.; Pellechia, Perry J.; Greytak, Andrew B.

doi:10.1039/d1cc03014k

Cited by 5 publications

(9 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To form p-type PbS inks without halides, we paired MPA with a weakly coordinating and basic solvent, benzylamine, achieving inks stable over a period of weeks or longer. 10…”

Section: Overview Of Surface Coordination In Nonpolar and Polar Solve...mentioning

confidence: 99%

“…To form p-type PbS inks without halides, we paired MPA with a weakly coordinating and basic solvent, benzylamine, achieving inks stable over a period of weeks or longer. 10 Polymeric ligands. The multiply-binding character of copolymer architectures with separate binding and solvating monomer residues 106,107,[114][115][116][117][118] offers increased colloidal stability in polar-organic and aqueous media for many types of semiconductor and metallic NCs, when compared to small molecules with only one or several binding motifs.…”

Section: Ligand Architecture and Colloidal Stabilitymentioning

confidence: 99%

“…Recent work in our group has highlighted the successful biphasic solution-phase exchange of PbS and ternary AgBiS 2 NCs to form inks for single deposition thin film fabrication. 10,158 Studies in polar organic solvents may also aid in prototyping surface chemistry that is aimed at biomedical applications in water. 83 Nonpolar/aqueous ligand exchanges.…”

Section: Ligand Exchange and Phase Transfersmentioning

confidence: 99%

“…4 Changes in NC surface chemistry may strongly affect physical properties, subsequent surface reactions, and colloidal stability. [5][6][7][8][9][10] A very prominent example of such challenges is found in colloidal quantum dots, where surface chemistry can affect photoluminescence quantum yield (PLQY), and is critically important to many applications. 11,12 For example, in optoelectronic devices, surfaces influence the stability of quantum dot inks and transport in assembled films.…”

Section: Introductionmentioning

confidence: 99%

“…11,12 For example, in optoelectronic devices, surfaces influence the stability of quantum dot inks and transport in assembled films. 10,13 In bioimaging applications, surfaces influence brightness, nonspecific binding, and addition of specific targeting or sensing functions. 14 In photocatalysis and upconversion, surfaces mediate access of molecular reactants to NC surfaces for photochemical processes.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Thermodynamics of nanocrystal–ligand binding through isothermal titration calorimetry

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…To form p-type PbS inks without halides, we paired MPA with a weakly coordinating and basic solvent, benzylamine, achieving inks stable over a period of weeks or longer. 10…”

Section: Overview Of Surface Coordination In Nonpolar and Polar Solve...mentioning

confidence: 99%

Section: Ligand Architecture and Colloidal Stabilitymentioning

confidence: 99%

Section: Ligand Exchange and Phase Transfersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Thermodynamics of nanocrystal–ligand binding through isothermal titration calorimetry

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

Fast Near‐Infrared Photodetectors Based on Nontoxic and Solution‐Processable AgBiS₂

Huang,

Nodari,

Furlan

et al. 2023

Small

View full text Add to dashboard Cite

Solution‐processable near‐infrared (NIR) photodetectors are urgently needed for a wide range of next‐generation electronics, including sensors, optical communications and bioimaging. However, it is rare to find photodetectors with >300 kHz cut‐off frequencies, especially in the NIR region, and many of the emerging inorganic materials explored are comprised of toxic elements, such as lead. Herein, solution‐processed AgBiS2 photodetectors with high cut‐off frequencies under both white light (>1 MHz) and NIR (approaching 500 kHz) illumination are developed. These high cut‐off frequencies are due to the short transit distances of charge‐carriers in the ultrathin photoactive layer of AgBiS2 photodetectors, which arise from the strong light absorption of this material, such that film thicknesses well below 120 nm are sufficient to absorb >65% of NIR to visible light. It is also revealed that ion migration plays a critical role in the photo‐response speed of these devices, and its detrimental effects can be mitigated by finely tuning the thickness of the photoactive layer, which is important for achieving low dark current densities as well. These outstanding characteristics enable the realization of air‐stable, real‐time heartbeat sensors based on NIR AgBiS2 photodetectors, which strongly motivates their future integration in high‐throughput systems.

show abstract

Characterizing the Semiconductor Nanocrystal Surface through Chemical Reactivity

2023

View full text Add to dashboard Cite

Metrics & MoreArticle Recommendations CONSPECTUS: Many desirable and undesirable properties of semiconductor nanocrystals (NCs) can be traced to the NC surface due to the large surface-to-volume ratio. Therefore, precise control of the NC surface is imperative to achieve NCs with the desired qualities.Ligand-specific reactivity and surface heterogeneity make it difficult to accurately control and tune the NC surface. Without a molecular-level appreciation of the NC surface chemistry, modulating the NC surface is impossible and the risk of introducing deleterious surface defects is imminent. To gain a more comprehensive understanding of the surface reactivity, we have utilized a variety of spectroscopic techniques and analytical methods in concert. This Account describes our use of robust characterization techniques and ligand exchange reactions in effort to establish a molecular-level understanding of NC surface reactivity. The utility of NCs in target applications such as catalysis and charge transfer hangs on precise tunability of NC ligands. Modulating the NC surface requires the necessary tools to monitor chemical reactions. One commonly utilized analytical method to achieve targeted surface compositions is 1 H nuclear magnetic resonance (NMR) spectroscopy. Here we describe our use of 1 H NMR spectroscopy to monitor chemical reactions at CdSe and PbS NC surfaces to identify ligand specific reactivity. However, seemingly straightforward ligand exchange reactions can vary widely depending on the NC materials and anchoring group. Some non-native X-type ligands will irreversibly displace native ligands. Other ligands exist in equilibrium with native ligands. Depending on the application, it is important to understand the nature of exchange reactions. This level of understanding can be obtained by extracting exchange ratios, exchange equilibrium, and reaction mechanism information from 1 H NMR spectroscopy to establish precise NC reactivity. Reactivity that occurs through multiple, parallel ligand exchange mechanisms can involve both the liberation of metal-based Z-type ligands in addition to reactivity of X-type ligands. In these reactions, 1 H NMR spectroscopy fails to discern between an X-type oleate or a Z-type Pb(oleate) 2 because only the alkene resonance of the organic constituent is probed by this method. Multiple, parallel reaction pathways occur when thiol ligands are introduced to oleate-capped PbS NCs. This necessitated the use of synergistic characterization methods including 1 H NMR spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS) to characterize both surface-bound and liberated ligands. Similar analytical methods have been employed to probe the NC topology, which is an important, but often overlooked, component to NC reactivity given the facet-specific reactivity of PbS NCs. Through the tandem use of NMR spectroscopy and ICP-MS, we have monitored the liberation of Pb(oleate) 2 as an L-type ligand is titrated to the NC to determin...

show abstract

A p-type PbS quantum dot ink with improved stability for solution processable optoelectronics

Abstract: A highly stable p-type PbS-QDs ink is prepared using a single-step biphasic ligand exchange route, overcoming instability encountered in previous reports. Chemical characterization of the ink reveals 3-mercaptopriopionic acid (MPA)...

Cited by 5 publications

References 25 publications

Thermodynamics of nanocrystal–ligand binding through isothermal titration calorimetry

Thermodynamics of nanocrystal–ligand binding through isothermal titration calorimetry

Fast Near‐Infrared Photodetectors Based on Nontoxic and Solution‐Processable AgBiS₂

Characterizing the Semiconductor Nanocrystal Surface through Chemical Reactivity

Contact Info

Product

Resources

About

A p-type PbS quantum dot ink with improved stability for solution processable optoelectronics

Abstract: A highly stable p-type PbS-QDs ink is prepared using a single-step biphasic ligand exchange route, overcoming instability encountered in previous reports. Chemical characterization of the ink reveals 3-mercaptopriopionic acid (MPA)...

Cited by 5 publications

References 25 publications

Thermodynamics of nanocrystal–ligand binding through isothermal titration calorimetry

Thermodynamics of nanocrystal–ligand binding through isothermal titration calorimetry

Fast Near‐Infrared Photodetectors Based on Nontoxic and Solution‐Processable AgBiS2

Characterizing the Semiconductor Nanocrystal Surface through Chemical Reactivity

Contact Info

Product

Resources

About

Fast Near‐Infrared Photodetectors Based on Nontoxic and Solution‐Processable AgBiS₂