Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
1,358
result(s) for
"Self-assembled monolayers"
Sort by:
Self‐assembled monolayers (SAMs) in inverted perovskite solar cells and their tandem photovoltaics application
2024
Self‐assembled monolayers (SAMs) employed in inverted perovskite solar cells (PSCs) have achieved groundbreaking progress in device efficiency and stability for both single‐junction and tandem configurations, owing to their distinctive and versatile ability to manipulate chemical and physical interface properties. In this regard, we present a comprehensive review of recent research advancements concerning SAMs in inverted perovskite single‐junction and tandem solar cells, where the prevailing challenges and future development prospects in the applications of SAMs are emphasized. We thoroughly examine the mechanistic roles of diverse SAMs in energy‐level regulation, interface modification, defect passivation, and charge transportation. This is achieved by understanding how interfacial molecular interactions can be finely tuned to mitigate charge recombination losses in inverted PSCs. Through this comprehensive review, we aim to provide valuable insights and references for further investigation and utilization of SAMs in inverted perovskite single‐junction and tandem solar cells. The self‐assembled monolayer plays a pivotal role in inverted single‐junction and tandem perovskite solar cells due to its distinctive and versatile ability to manipulate chemical and physical interface properties, serving as a key factor in charge transport, interface modification, energy‐level modulation, and defect passivation.
Journal Article
Surface NMR using quantum sensors in diamond
by
Bartl, Johannes D.
,
Bucher, Dominik B.
,
Allert, Robin D.
in
Aluminum
,
Aluminum oxide
,
Applied Physical Sciences
2022
NMR is a noninvasive, molecular-level spectroscopic technique widely used for chemical characterization. However, it lacks the sensitivity to probe the small number of spins at surfaces and interfaces. Here, we use nitrogen vacancy (NV) centers in diamond as quantum sensors to optically detect NMR signals from chemically modified thin films. To demonstrate the method’s capabilities, aluminum oxide layers, common supports in catalysis and materials science, are prepared by atomic layer deposition and are subsequently functionalized by phosphonate chemistry to form self-assembled monolayers. The surface NV-NMR technique detects spatially resolved NMR signals from the monolayer, indicates chemical binding, and quantifies molecular coverage. In addition, it can monitor in real time the formation kinetics at the solid–liquid interface. With our approach, we show that NV quantum sensors are a surface-sensitive NMR tool with femtomole sensitivity for in situ analysis in catalysis, materials, and biological research.
Journal Article
Co-deposition of hole-selective contact and absorber for improving the processability of perovskite solar cells
2023
Simplifying the manufacturing processes of renewable energy technologies is crucial to lowering the barriers to commercialization. In this context, to improve the manufacturability of perovskite solar cells (PSCs), we have developed a one-step solution-coating procedure in which the hole-selective contact and perovskite light absorber spontaneously form, resulting in efficient inverted PSCs. We observed that phosphonic or carboxylic acids, incorporated into perovskite precursor solutions, self-assemble on the indium tin oxide substrate during perovskite film processing. They form a robust self-assembled monolayer as an excellent hole-selective contact while the perovskite crystallizes. Our approach solves wettability issues and simplifies device fabrication, advancing the manufacturability of PSCs. Our PSC devices with positive–intrinsic–negative (p-i-n) geometry show a power conversion efficiency of 24.5% and retain >90% of their initial efficiency after 1,200 h of operating at the maximum power point under continuous illumination. The approach shows good generality as it is compatible with different self-assembled monolayer molecular systems, perovskites, solvents and processing methods.
Improving the manufacturability of perovskite solar cells is key to their deployment. Zheng et al. report a one-step deposition of the hole-selective and absorber layers that addresses wettability issues and simplifies the fabrication process.
Journal Article
Molecular surface coverage standards by reference-free GIXRF supporting SERS and SEIRA substrate benchmarking
2024
Non-destructive reference-free grazing incidence X-ray fluorescence (RF-GIXRF) is proposed as a highly effective analytical technique for extracting molecular arrangement density in self-assembled monolayers. The establishment of surface density standards through RF-GIXRF impacts various applications, from calibrating laboratory XRF setups to expanding its applicability in materials science, particularly in surface coating scenarios with molecular assemblies. Accurate determination of coverage density is crucial for proper functionalization and interaction, such as in assessing the surface concentration of probes on plasmonic nanostructures. However, limited synchrotron radiation access hinders widespread use, prompting the need for molecular surface density standards, especially for benchmarking substrates for surface-enhanced Raman and infrared absorption spectroscopies (SERS and SEIRA) as well as associated surface-enhanced techniques. Using reproducible densities on gold ensures a solid evaluation of the number of molecules contributing to enhanced signals, facilitating comparability across substrates. The research discusses the importance of employing molecular surface density standards for advancing the field of surface-enhanced spectroscopies, encouraging collaborative efforts in protocol development and benchmarking in surface science.
Journal Article
Gas‐Assisted Spray Coating of Perovskite Solar Cells Incorporating Sprayed Self‐Assembled Monolayers
2022
Self‐assembled monolayers (SAMs) are becoming widely utilized as hole‐selective layers in high‐performance p‐i‐n architecture perovskite solar cells. Ultrasonic spray coating and airbrush coating are demonstrated here as effective methods to deposit MeO‐2PACz; a carbazole‐based SAM. Potential dewetting of hybrid perovskite precursor solutions from this layer is overcome using optimized solvent rinsing protocols. The use of air‐knife gas‐quenching is then explored to rapidly remove the volatile solvent from an MAPbI3 precursor film spray‐coated onto an MeO‐2PACz SAM, allowing fabrication of p‐i‐n devices with power conversion efficiencies in excess of 20%, with all other layers thermally evaporated. This combination of deposition techniques is consistent with a rapid, roll‐to‐roll manufacturing process for the fabrication of large‐area solar cells. Carbazole‐based self‐assembled monolayers are becoming a dominant hole‐transporting layer in p‐i‐n perovskite solar cells, combining stability, efficiency, and low‐cost. Here, spray coating and airbrush pen coating of MeO‐2PACz are used to fabricate high‐quality transport layers. This is combined with gas‐quenched spray‐coated perovskite layers, to realize solar cells with power conversion efficiencies in excess of 20%.
Journal Article
Gold nanoparticles with patterned surface monolayers for nanomedicine: current perspectives
by
Marson, Domenico
,
Posocco, Paola
,
Pricl, Sabrina
in
Biochemistry
,
Biological and Medical Physics
,
Biomedical and Life Sciences
2017
Molecular self-assembly is a topic attracting intense scientific interest. Various strategies have been developed for construction of molecular aggregates with rationally designed properties, geometries, and dimensions that promise to provide solutions to both theoretical and practical problems in areas such as drug delivery, medical diagnostics, and biosensors, to name but a few. In this respect, gold nanoparticles covered with self-assembled monolayers presenting nanoscale surface patterns—typically patched, striped or Janus-like domains—represent an emerging field. These systems are particularly intriguing for use in bio-nanotechnology applications, as presence of such monolayers with three-dimensional (3D) morphology provides nanoparticles with surface-dependent properties that, in turn, affect their biological behavior. Comprehensive understanding of the physicochemical interactions occurring at the interface between these versatile nanomaterials and biological systems is therefore crucial to fully exploit their potential. This review aims to explore the current state of development of such patterned, self-assembled monolayer-protected gold nanoparticles, through step-by-step analysis of their conceptual design, synthetic procedures, predicted and determined surface characteristics, interactions with and performance in biological environments, and experimental and computational methods currently employed for their investigation.
Journal Article
Factors influencing surface coverage and structural organization of phosphonic acid self-assembled monolayers on zinc oxide
by
Alayou, Surafel
,
Tizazu, Getachew
,
Mengesha, Mekdes
in
Acids
,
Characterization and Evaluation of Materials
,
Condensed Matter Physics
2024
This study investigates the effects of solvent type, ODPA concentration, and solution temperature on the growth, surface coverage, and structural order of n-octadecylphosphonic acid (ODPA) self-assembled monolayers (SAMs) on zinc oxide (ZnO) surfaces. We explore the impacts of isopropanol and ethanol as solvents, considering their differing dielectric constants and lower toxicity compared to non-polar alternatives like toluene. The results indicate that ODPA SAMs formed more rapidly in isopropanol, with a growth rate of 0.7% per minute, compared to 0.2% per minute in ethanol. However, ethanol resulted in slightly higher surface coverage (97%) than isopropanol (96%). Moreover, increasing the ODPA concentration from 0.03 to 0.14 mM enhanced surface coverage; however, further increases in concentration did not lead to a corresponding increase in SAM coverage due to molecular interactions. The solution temperature also significantly influenced the growth rate of the SAM, with temperatures rising from 30 to 60 °C enhancing growth. However, higher temperatures (above 60 °C) affected the SAM structure, leading to defects in the monolayer. This study provides a comprehensive understanding of how solvent type, concentration, and solution temperature influence SAM formation, offering valuable insights for optimizing deposition conditions to enhance device performance in optoelectronic applications.
Journal Article
Bioactive Coatings on Titanium: A Review on Hydroxylation, Self-Assembled Monolayers (SAMs) and Surface Modification Strategies
by
Moreno-Benítez, Isabel
,
Vilas-Vilela, José Luis
,
Pérez-Álvarez, Leyre
in
Alloys
,
Atmospheric corrosion
,
Biocompatibility
2021
Titanium (Ti) and its alloys have been demonstrated over the last decades to play an important role as inert materials in the field of orthopedic and dental implants. Nevertheless, with the widespread use of Ti, implant-associated rejection issues have arisen. To overcome these problems, antibacterial properties, fast and adequate osseointegration and long-term stability are essential features. Indeed, surface modification is currently presented as a versatile strategy for developing Ti coatings with all these challenging requirements and achieve a successful performance of the implant. Numerous approaches have been investigated to obtain stable and well-organized Ti coatings that promote the tailoring of surface chemical functionalization regardless of the geometry and shape of the implant. However, among all the approaches available in the literature to functionalize the Ti surface, a promising strategy is the combination of surface pre-activation treatments typically followed by the development of intermediate anchoring layers (self-assembled monolayers, SAMs) that serve as the supporting linkage of a final active layer. Therefore, this paper aims to review the latest approaches in the biomedical area to obtain bioactive coatings onto Ti surfaces with a special focus on (i) the most employed methods for Ti surface hydroxylation, (ii) SAMs-mediated active coatings development, and (iii) the latest advances in active agent immobilization and polymeric coatings for controlled release on Ti surfaces.
Journal Article
Carbazole‐Based Self‐Assembled Monolayers for Hole Transport in Photovoltaics: A Molecular Engineering Perspective
by
Tian, Maosong
,
Lv, Menglan
,
Tian, Jingfu
in
carbazole‐derivative
,
chemistry structure modification
,
hole‐transporting layers
2026
Self‐assembled monolayers (SAMs) have proven to be highly efficient hole‐transporting layers (HTLs) due to their advantages, including low cost, minimal material consumption, ease of synthesis, negligible optical loss, and exceptional stability. Recently, carbazole‐based SAM HTLs have considerably improved the power conversion efficiency (PCE) of organic solar cells (OSCs) and perovskite solar cells (PSCs)—with PCEs reaching 21% and 27%, respectively. This review begins with a concise overview of the chemical structure of SAMs, emphasizing the recent advancements achieved by carbazole‐based SAMs in the photovoltaics (PVs) sector. We then systematically summarize the modifications made to the chemical structure of carbazole‐based SAMs to optimize their interface dipole, surface wettability, and interface defects. Especially for functional group, the modification techniques are categorized into four main types: methoxylation, conjugation, halogenation, and asymmetrization. Finally, several challenges, including solubility, film quality, and stability, along with potential solutions for these issues are discussed. We hope this review serves as a valuable guide and source of inspiration for the design of SAM HTLs, ultimately enhancing the performance of PV devices. This review systematically and comprehensively summarized the molecular design principles of carbazole‐derived SAMs concerning the anchor, spacer, and functional group, and their impacts on performance of photovoltaic device. Intended to provide insights for the development of high‐performance, cost‐effective, and scalable interface materials for next‐generation optoelectronic devices.
Journal Article
Self-Assembled Monolayers: Versatile Uses in Electronic Devices from Gate Dielectrics, Dopants, and Biosensing Linkers
2021
Self-assembled monolayers (SAMs), molecular structures consisting of assemblies formed in an ordered monolayer domain, are revisited to introduce their various functions in electronic devices. SAMs have been used as ultrathin gate dielectric layers in low-voltage transistors owing to their molecularly thin nature. In addition to the contribution of SAMs as gate dielectric layers, SAMs contribute to the transistor as a semiconducting active layer. Beyond the transistor components, SAMs have recently been applied in other electronic applications, including as remote doping materials and molecular linkers to anchor target biomarkers. This review comprehensively covers SAM-based electronic devices, focusing on the various applications that utilize the physical and chemical properties of SAMs.
Journal Article