From Monolayer to Multilayer N‐Channel Polymeric Field‐Effect Transistors with Precise Conformational Order

Fabiano, Simone; Musumeci, Chiara; Chen, Zhihua; Scandurra, Antonino; Wang, He; Loo, Yueh Lin; Facchetti, Antonio; Pignataro, Bruno

doi:10.1002/adma.201103800

Cited by 115 publications

(147 citation statements)

References 49 publications

(22 reference statements)

Supporting

Mentioning

137

Contrasting

Unclassified

Order By: Relevance

“…This particular morphology allows good electron transport in both organic diodes and field-effect transistors (OFETs), with high in-plane mobilities of ∼0.1-0.6 cm 2 ·V -1 ·s -1 even in the presence of a substantial degree of disorder (11). However, film morphologies with predominantly edge-on oriented polymer chains were observed to yield lower performance in both diodes and top-gated OFETs because of the reduced out-of-plane mobility and larger injection barrier (16)(17)(18)(19). In a recent publication, Neher and coworkers also showed that this polymer has a strong tendency to aggregate, which greatly affects the bulk optical and electrical properties (20,21).…”

mentioning

confidence: 99%

Experimental evidence that short-range intermolecular aggregation is sufficient for efficient charge transport in conjugated polymers

Wang

Fabiano

Himmelberger

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

180

206

View full text Add to dashboard Cite

Efficiency, current throughput, and speed of electronic devices are to a great extent dictated by charge carrier mobility. The classic approach to impart high carrier mobility to polymeric semiconductors has often relied on the assumption that extensive order and crystallinity are needed. Recently, however, this assumption has been challenged, because high mobility has been reported for semiconducting polymers that exhibit a surprisingly low degree of order. Here, we show that semiconducting polymers can be confined into weakly ordered fibers within an inert polymer matrix without affecting their charge transport properties. In these conditions, the semiconducting polymer chains are inhibited from attaining longrange order in the π-stacking or alkyl-stacking directions, as demonstrated from the absence of significant X-ray diffraction intensity corresponding to these crystallographic directions, yet still remain extended along the backbone direction and aggregate on a local length scale. As a result, the polymer films maintain high mobility even at very low concentrations. Our findings provide a simple picture that clarifies the role of local order and connectivity of domains.organic electronics | conjugated polymers | aggregation | charge transport C onjugated polymers have received significant scientific attention as the active material in devices for printed and flexible organic electronics (1, 2). Owing to their versatile chemical synthesis, inexpensive processability from solution, and unique mechanical flexibility, these materials are in fact promising for a vast array of devices in future low-cost and distributed technologies, such as integrated systems for electronic labels targeting safety, security, and surveillance applications (3). The rational design of new organic semiconductors has been guided by a thorough investigation of their limitations in charge transport, leading to the development of high-performance materials for next-generation electronic applications such as low-cost displays, solar cells, sensors, and logic circuits (4, 5). For more than a decade research has primarily focused on increasing the long-range order and the crystallinity of conjugated polymers as a strategy to improve the solid-state charge transport properties. As a result, the charge carrier mobility has increased by several orders of magnitude through the design and synthesis of highly ordered polymers. However, recent studies have suggested that the key to designing high-mobility polymers is not to increase their crystallinity but rather to improve their tolerance for disorder by allowing more efficient intra-and intermolecular charge transport pathways (6). This observation explains why mobility values obtained from recently designed seemingly disordered organic semiconductors often exceed those of polymers having a high degree of crystallinity (∼1 cm 2 ·V -1 ·s -1 ) (7-10). Indeed, polymers may exhibit little longrange order, as measured by X-ray diffraction (XRD), and yet display a remarkable degree of short-range or...

show abstract

mentioning

confidence: 99%

Experimental evidence that short-range intermolecular aggregation is sufficient for efficient charge transport in conjugated polymers

Wang

Fabiano

Himmelberger

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

180

206

View full text Add to dashboard Cite

show abstract

“…The hole mobility of the monolayer FET can reach 0.014 cm 2 V −1 s −1 with an average µ h of 0.008 cm 2 V −1 s −1 , which is among the highest charge mobility reported for FETs with ultrathin films prepared with Langmuir technique. [29][30][31][32][33][34][35] Moreover, the monolayer FET exhibits relatively high I on/off (10 4 -10 6 ). µ h increased to 0.015 and 0.02 cm 2 V −1 s −1 for FETs with bilayer and threelayer ultrathin films, respectively.…”

Section: Thin Film Field-effect Transistorsmentioning

confidence: 99%

“…This can be attributed to the fact that PDPP3T1 entails amphiphilic side chains. According to previous studies, [35,38] the hydrophilic part (TEEG chains) of PDPP3T1 is assumed to be located in the water subphase, while the hydrophobic part of the polymer is expected to adopt a perpendicular orientation with respect to the water surface.…”

Section: Formation Of Monolayer Thin Film At Air-water Interfacementioning

confidence: 99%

“…In fact, Langmuir technique was successfully utilized to transfer monolayer thin films of organic and polymeric semiconductors onto the substrates to fabricate FETs. [29][30][31][32][33][34][35] For instance, Yli-Lahti and co-workers first reported FETs with Langmuir-Blodgett (LB) films of poly(3-hexylthicphene)/ arachidic acid, but the resulting FETs exhibited rather low charge mobilities. [34] This is probably due to the fact that the LB films contain arachidic acid which is required for the formation of the polymer LB films at air-water interface.…”

mentioning

confidence: 99%

“…Facchetti and Pignataro and co-workers prepared n-type monolayer FET with naphthalene diimide based polymer (P (NDI2OD-T2)) by using Langmuir-Schaefer method. [35] These conjugated polymers are basically hydrophobic, but it is known that amphiphilic molecules with both hydrophobic and hydrophilic moieties can form more ordered monolayers at the air-water interface. [36][37][38] Leclerc and co-workers studied the formation of LB monolayers at air-water interface and the transfer of the monolayers onto the substrate for the conjugated polymer with both alkyl and oligo(ethylene glycol) side chains, but the semiconducting properties of the monolayers were not addressed.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Diketopyrrolopyrrole‐Based Semiconducting Polymer with Both Hydrophobic Alkyl and Hydrophilic Tetraethylene Glycol Chains for Monolayer Transistor and Sensing Application

Yang

Zhang

Chen

et al. 2017

Adv Elect Materials

View full text Add to dashboard Cite

studies also suggest that the first few layers of organic/polymeric semiconductors play key roles in determining the performances of FETs. [10][11][12][13][14][15] Moreover, downscaling the film thickness to a single molecular layer is of technological interest for the realization of bottomup electronic devices. [16][17][18] In particular, monolayer organic FETs (OFETs) are beneficial for sensing applications as the binding of the respective analytes with the semiconducting monolayer is expected to affect the charge transporting. [19][20][21][22][23] Consequently, such sensors with monolayer FETs can show high sensitivity and fast response.Various approaches have been explored to fabricate FETs with ultrathin semiconducting films. These include unconventional spin-coating and formation of self-assembly monolayer on surface. [24][25][26][27][28] Langmuir deposition method is known to enable the realization of monolayers at the air/liquid interface with precision control over the molecule lateral packing density. In fact, Langmuir technique was successfully utilized to transfer monolayer thin films of organic and polymeric semiconductors onto the substrates to fabricate FETs. [29][30][31][32][33][34][35] For instance, Yli-Lahti and co-workers first reported FETs with Langmuir-Blodgett (LB) films of poly(3-hexylthicphene)/ arachidic acid, but the resulting FETs exhibited rather low charge mobilities. [34] This is probably due to the fact that the LB films contain arachidic acid which is required for the formation of the polymer LB films at air-water interface. Facchetti and Pignataro and co-workers prepared n-type monolayer FET with naphthalene diimide based polymer (P (NDI2OD-T2)) by using Langmuir-Schaefer method. [35] These conjugated polymers are basically hydrophobic, but it is known that amphiphilic molecules with both hydrophobic and hydrophilic moieties can form more ordered monolayers at the air-water interface. [36][37][38] Leclerc and co-workers studied the formation of LB monolayers at air-water interface and the transfer of the monolayers onto the substrate for the conjugated polymer with both alkyl and oligo(ethylene glycol) side chains, but the semiconducting properties of the monolayers were not addressed. [38] Functional field-effect transistors (FETs) have received increasing attention in recent years. Herein, it is demonstrated that the incorporation of hydrophilic tetraethylene glycol (TEEG) chains into the diketopyrrolopyrrole (DPP)-based semiconducting polymer (PDPP3T1) can facilitate the formation of polymeric monolayer at the air-water interface, and the resulting field-effect transistors (FETs) show sensitive and selective response toward alcohol vapor. By using the Langmuir-Schaefer method, monolayer and ultrathin films from bilayer to five-layer can be successfully prepared. Interestingly, nanopores with sizes of 50-100 nm are formed within the monolayer film, as observed by using atomic force microscopy. The monolayer FET exhibits relatively high hole mobilities up to 0.014 cm 2 V −1 s −...

show abstract

High‐Mobility Air‐Stable Naphthalene Diimide‐Based Copolymer Containing Extended π‐Conjugation for n‐Channel Organic Field Effect Transistors

Kim

Amegadze

Kang

et al. 2013

Adv Funct Materials

174

158

View full text Add to dashboard Cite

A high-performance naphthalene diimide (NDI)-based conjugated polymer for use as the active layer of n-channel organic fi eld-effect transistors (OFETs) is reported. The solution-processable n-channel polymer is systematically designed and synthesized with an alternating structure of long alkyl substituted-NDI and thienylene-vinylene-thienylene units (PNDI-TVT). The material has a well-controlled molecular structure with an extended π -conjugated backbone, with no increase in the LUMO level, achieving a high mobility and highly ambient stable n-type OFET. The top-gate, bottomcontact device shows remarkably high electron charge-carrier mobility of up to 1.8 cm 2 V − 1 s − 1 ( I on / I off = 10 6 ) with the commonly used polymer dielectric, poly(methyl methacrylate) (PMMA). Moreover, PNDI-TVT OFETs exhibit excellent air and operation stability. Such high device performance is attributed to improved ππ intermolecular interactions owing to the extended π -conjugation, apart from the improved crystallinity and highly interdigitated lamellar structure caused by the extended ππ backbone and long alkyl groups.the morphology of the polymer fi lm, with its mixture of edge-on and face-on orientation, auto-encapsulation effect by the overlaid gate and gate dielectric layer, and low LUMO energy level of the specifi cally designed polymer. ConclusionsWe designed and synthesized a new solution-processable n-channel polymer with an extended π -conjugated backbone, without increasing the LUMO level. The obtained polymer, PNDI-TVT, had a well-controlled alternating structure consisting of a long alkyl chain-substituted NDI as an electron acceptor unit and TVT as a donor unit. The PNDI-TVT copoly mer demonstrated a remarkably high electron-carrier mobility of up to 1.8 cm 2 V − 1 s − 1 ( I on / I off = 10 6 ) and high air and bias stress stability. To the best of our knowledge, this newly developed material showed the highest n-type mobility, in combination with excellent air and operation stabilities, among the reported n-channel conjugated polymers. The superior performance of PNDI-TVT OFET was attributed to improved ππ intermolecular interactions because of the extended π -conjugation, improved crystallinity with a highly interdigitated lamellar structure owing to the extended backbone and long alkyl groups, and mixed face-on and edge-on orientation.

show abstract

From Monolayer to Multilayer N‐Channel Polymeric Field‐Effect Transistors with Precise Conformational Order

Cited by 115 publications

References 49 publications

Experimental evidence that short-range intermolecular aggregation is sufficient for efficient charge transport in conjugated polymers

Experimental evidence that short-range intermolecular aggregation is sufficient for efficient charge transport in conjugated polymers

Diketopyrrolopyrrole‐Based Semiconducting Polymer with Both Hydrophobic Alkyl and Hydrophilic Tetraethylene Glycol Chains for Monolayer Transistor and Sensing Application

High‐Mobility Air‐Stable Naphthalene Diimide‐Based Copolymer Containing Extended π‐Conjugation for n‐Channel Organic Field Effect Transistors

Contact Info

Product

Resources

About