Solution-processable Ti3C2Tx nanosheets as an efficient hole transport layer for high-performance and stable polymer solar cells
26 Sep 2019-Journal of Materials Chemistry C (The Royal Society of Chemistry)-Vol. 7, Iss: 37, pp 11549-11558
TL;DR: In this paper, 2D Ti3C2Tx, a classic representative of the MXene family, is fabricated and functioned as a hole transport layer (HTL) in polymer solar cells (PSCs) due to its features of outstanding metallic conductivity, excellent optical transparency, suitable work function and superior mechanical properties.
Abstract: MXenes, a newly interesting family of two-dimensional (2D) materials, have recently attracted wide attention owing to their unique photoelectric properties. In this study, 2D Ti3C2Tx, a classic representative of the MXene family, is fabricated and functioned as a hole transport layer (HTL) in polymer solar cells (PSCs) due to its features of outstanding metallic conductivity, excellent optical transparency, suitable work function, and superior mechanical properties. The Ti3C2Tx nanosheets deposited from neutral solutions are incorporated between the photoactive layer and the anode electrode as HTLs to facilitate charge transport and collection characteristics in PSCs. The results show that the Ti3C2Tx film possesses good light transmission and high conductivity. The photovoltaic characteristics of the Ti3C2Tx-based devices are systematically investigated. It is demonstrated that the incorporation of Ti3C2Tx as a HTL endows PSCs with superior charge extraction capability, exhibiting a significantly higher power conversion efficiency (PCE) of 10.53% than that of the only ITO-based device (4.21%) with PBDB-T as the donor and ITIC as the acceptor. Such photovoltaic performance also outperforms that of the state-of-the-art PEDOT:PSS-based devices (10.11%). Furthermore, the Ti3C2Tx-based device also shows better long-term stability under atmospheric conditions without any encapsulation than the PEDOT:PSS devices, which indicates that the 2D Ti3C2Tx material possesses great potential in PSCs.
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TL;DR: In this article, all developments and applications of the Ti3C2Tx MXene (here, it is noteworthy that there are still no reports on other MXenes' application in photovoltaics by far) as additive, electrode and hole/electron transport layer in solar cells are detailedly summarized, and meanwhile, the problems existing in the related studies are also discussed.
Abstract: Application of two-dimensional MXene materials in photovoltaics has attracted increasing attention since the first report in 2018 due to their metallic electrical conductivity, high carrier mobility, excellent transparency, tunable work function and superior mechanical property. In this review, all developments and applications of the Ti3C2Tx MXene (here, it is noteworthy that there are still no reports on other MXenes’ application in photovoltaics by far) as additive, electrode and hole/electron transport layer in solar cells are detailedly summarized, and meanwhile, the problems existing in the related studies are also discussed. In view of these problems, some suggestions are given for pushing exploration of the MXenes’ application in solar cells. It is believed that this review can provide a comprehensive and deep understanding into the research status and, moreover, helps widen a new situation for the study of MXenes in photovoltaics.
128 citations
23 Apr 2020
TL;DR: Toluene is one of the harmful volatile organic compounds (VOCs) for both human health and environments as mentioned in this paper, thus, to prevent the hazardous effect of toluene, fast detection at an early stage is needed.
Abstract: Toluene is one of the harmful volatile organic compounds (VOCs) for both human health and environments. Thus, to prevent the hazardous effect of toluene, fast detection at an early stage is needed....
119 citations
01 Mar 2021
TL;DR: In this article, the authors review how MXene processing methods, their volume fraction, and their incorporation into polymer hosts impact the properties and performance of a wide variety of nanocomposites.
Abstract: MXenes are a relatively new and exciting class of two-dimensional materials, which offer a wide range of compositions and excellent properties including ease of dispersibility and metallic conductivity. These properties render them promising candidates for use as fillers in polymer nanocomposites. Herein, we review how MXene processing methods, their volume fraction, and their incorporation into polymer hosts impact the properties and performance of a wide variety of nanocomposites. Several challenges and barriers that remain are discussed.
80 citations
TL;DR: In this article, the authors summarized the recent development and progress in the preparation of 2D MXenes from chemical and physical routes, as well as the intercalation and delamination techniques including cation intercalations and physical delamination.
Abstract: Due to their distinctive two-dimensional (2D) structure and excellent properties, MXenes have got much attention and developed very fast since their discovery in 2011. Generally, 2D MXenes are prepared by selectively etching the A layer from the MAX phases with hazardous fluorine-based acids. Later, more and more moderate routes, such as Lewis acid etching and chemical vapor deposition, have been successfully developed to prepare 2D MXenes without using hazardous etchants. Meanwhile, the intercalation or delamination is also quite important to obtain 2D MXene layers with high quality and high yield. Furthermore, due to the outstanding optoelectronic properties, flexibility, ductility and stability, flexible devices based on 2D MXenes and their nano-composites are quite promising in different fields, such as organic electronics, supercapacitors, metal-ion batteries, electromagnetic interference shielding, sensors, photocatalysis and photothermal therapies, etc. In this review, we firstly summarize the recent development and progress in the preparation of 2D MXenes from chemical and physical routes, as well as the intercalation and delamination techniques including cation intercalation and physical delamination. Furthermore, the applications of 2D MXene in flexible devices have been well discussed from different using routes of MXene including pure MXene, MXene/2D materials, MXene/1D materials and MXene/polymers. Finally, we give a conclusion to this interview and make a perspective on the future directions of 2D MXenes considering the key issues in the MXene community.
65 citations
TL;DR: In this paper, a novel ZnO/Ti3C2Tx nanohybrid composite film was used for electron transport layers (ETLs) in fullerene and non-fullerene polymer solar cells.
62 citations
References
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TL;DR: 2D nanosheets, composed of a few Ti 3 C 2 layers and conical scrolls, produced by the room temperature exfoliation of Ti 3 AlC 2 in hydrofl uoric acid are reported, which opens a door to the synthesis of a large number of other 2D crystals.
Abstract: Currently, however, there are relatively few such atomically layered solids. [ 2–5 ] Here, we report on 2D nanosheets, composed of a few Ti 3 C 2 layers and conical scrolls, produced by the room temperature exfoliation of Ti 3 AlC 2 in hydrofl uoric acid. The large elastic moduli predicted by ab initio simulation, and the possibility of varying their surface chemistries (herein they are terminated by hydroxyl and/or fl uorine groups) render these nanosheets attractive as polymer composite fi llers. Theory also predicts that their bandgap can be tuned by varying their surface terminations. The good conductivity and ductility of the treated powders suggest uses in Li-ion batteries, pseudocapacitors, and other electronic applications. Since Ti 3 AlC 2 is a member of a 60 + group of layered ternary carbides and nitrides known as the MAX phases, this discovery opens a door to the synthesis of a large number of other 2D crystals. Arguably the most studied freestanding 2D material is graphene, which was produced by mechanical exfoliation into single-layers in 2004. [ 1 ] Some other layered materials, such as hexagonal BN, [ 2 ] transition metal oxides, and hydroxides, [ 4 ] as well as clays, [ 3 ] have also been exfoliated into 2D sheets. Interestingly, exfoliated MoS 2 single layers were reported as early as in 1986. [ 5 ] Graphene is fi nding its way to applications ranging from supercapacitor electrodes [ 6 ] to reinforcement in composites. [ 7 ] Although graphene has attracted more attention than all other 2D materials combined, its simple chemistry and the weak van der Waals bonding between layers in multilayer structures limit its use. Complex, layered structures that contain more than one element may offer new properties because they
6,846 citations
TL;DR: In this article, a new family of two-dimensional early transition metal carbides and carbonitrides, called MXenes, was discovered and a detailed outlook for future research on MXenes is also presented.
Abstract: Recently a new, large family of two-dimensional (2D) early transition metal carbides and carbonitrides, called MXenes, was discovered. MXenes are produced by selective etching of the A element from the MAX phases, which are metallically conductive, layered solids connected by strong metallic, ionic, and covalent bonds, such as Ti2AlC, Ti3AlC2, and Ta4AlC3. MXenes combine the metallic conductivity of transition metal carbides with the hydrophilic nature of their hydroxyl or oxygen terminated surfaces. In essence, they behave as “conductive clays”. This article reviews progress—both experimental and theoretical—on their synthesis, structure, properties, intercalation, delamination, and potential applications. MXenes are expected to be good candidates for a host of applications. They have already shown promising performance in electrochemical energy storage systems. A detailed outlook for future research on MXenes is also presented.
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TL;DR: In this paper, a ladder-type electron-deficient core-based central fused ring (Dithienothiophen[3.2-b]- pyrrolobenzothiadiazole) with a benzothiadiadiazoles (BT) core was proposed to fine-tune its absorption and electron affinity.
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TL;DR: This study demonstrates the spontaneous intercalation of cations from aqueous salt solutions between two-dimensional (2D) Ti3C2 MXene layers, and provides a basis for exploring a large family of 2D carbides and carbonitrides in electrochemical energy storage applications using single- and multivalent ions.
Abstract: The intercalation of ions into layered compounds has long been exploited in energy storage devices such as batteries and electrochemical capacitors However, few host materials are known for ions much larger than lithium We demonstrate the spontaneous intercalation of cations from aqueous salt solutions between two-dimensional (2D) Ti3C2 MXene layers MXenes combine 2D conductive carbide layers with a hydrophilic, primarily hydroxyl-terminated surface A variety of cations, including Na+, K+, NH4+, Mg2+, and Al3+, can also be intercalated electrochemically, offering capacitance in excess of 300 farads per cubic centimeter (much higher than that of porous carbons) This study provides a basis for exploring a large family of 2D carbides and carbonitrides in electrochemical energy storage applications using single- and multivalent ions
3,018 citations
TL;DR: Two-dimensional transition metal carbides, carbonitrides, and nitrides (MXenes) were discovered in 2011 and more than 20 different compositions have been synthesized by the selective etching of MAX phase and other precursors and many more theoretically predicted as mentioned in this paper.
Abstract: Two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides (MXenes) were discovered in 2011. Since the original discovery, more than 20 different compositions have been synthesized by the selective etching of MAX phase and other precursors and many more theoretically predicted. They offer a variety of different properties, making the family promising candidates in a wide range of applications, such as energy storage, electromagnetic interference shielding, water purification, electrocatalysis, and medicine. These solution-processable materials have the potential to be highly scalable, deposited by spin, spray, or dip coating, painted or printed, or fabricated in a variety of ways. Due to this promise, the amount of research on MXenes has been increasing, and methods of synthesis and processing are expanding quickly. The fast evolution of the material can also be noticed in the wide range of synthesis and processing protocols that determine the yield of delamination, as well as the quality...
2,559 citations