Utilizing the Diffusion of Fluorinated Polymers to Modify the Semiconductor/Dielectric Interface in Solution-Processed Conjugated Polymer Field-Effect Transistors

Yang, Yuhui; Hong, Yongming; Wang, Xinping

doi:10.1021/acsami.0c23058

Cited by 29 publications

(23 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is clearly observed that the introduction of -CF 3 into the PI system indeed decreases the trap depth in ESP map (Figure 1a-c) and increases the energy level of LUMO (Figure 1d-f), which indicates the reduction of the system polarizability due to the small dipole polarization ability of CF bonds. [23][24][25] In addition, the incorporation of -CF3 could effectively prevent the close accumulation of polymer chains to increase the fractional free volume of polymer dielectrics (Figure 1g-i) for higher light transmittance (Figure S1, Supporting Information). The PI-based phototransistor was fabricated using a bottom-gate top-contact geometry, as shown in Figure 2a.…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7] By using OFETs as a photosensitive unit, organic phototransistors (OPTs) have the dielectric layer and the maximum reduction of the generation of traps at the interface of semiconductor/dielectric layer, so as to impede the charge-trapping process and improve carrier mobility. [23][24][25] Although, some works have been done to prove that the devices with fluorinated PI could enhance the mobility, [26,27] the effect of the amount of fluorine functional groups on its mobility has not yet been studied, to say nothing of the modulation effect of fluorine functional groups on photogenerated charge carrier in phototransistors.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluorinated Dielectrics‐Modulated Organic Phototransistors and Flexible Image Sensors

Jiang

Zheng

et al. 2022

Advanced Optical Materials

View full text Add to dashboard Cite

gathered lots of attention due to gate tunability and signal amplification for flexible active-matrix sensing. [8][9][10] In the previous studies of OPTs, the interface engineering of polymeric dielectrics offers an effective approach to modulate the performance of the devices. [11][12][13] As one of the representatives of polymeric dielectrics for modulation, aromatic polyimide (PI) has become a promising candidate for gate dielectric layer with good feasibility for fabrication of organic electronic devices due to its excellent thermal stability, chemical resistance, and mechanical flexibility. [14][15][16][17] However, in our previous work, we found that the weak van der Waals interaction between the PI (KAPTON) chains led to a flat 2D structure at the interface resulting in the disorder molecular stacking of planar molecules for low mobility. [18] To this end, the functionalization of PI with selfassembly monolayer could improve the mobility by an order of magnitude with a value up to 0.462 cm 2 V −1 s −1 . [19] Besides, the incorporation of fluorine functional groups into PI molecules will enhance its surface hydrophobicity and reduce the surface energy of the interface. [20][21][22] Furthermore, due to the chemical inertia, hydrophobicity, and low polarizability of CF bond, the adsorption of water and oxygen molecules in the air can be inhibited by fluorinated PI, resulting in the reduction of the polarity of It is generally believed that the incorporation of fluorine functional groups into dielectrics can effectivelyimpede the charge-trapping process and improve carrier mobility. However, the relationship between the device performance and fluorinated groups is still not clear and also the modulation effect of fluorine functional groups on photogenerated charge carrier in phototransistors has not yet been investigated. Herein, phototransistors are constructed by using three kinds of gate dielectric layers with different fluorinated groups to exploit the effect of fluorine functional groups. It is concluded that the presence of fluorinated groups indeed increases the transistor mobility and optical figures of merit in phototransistors compared to the device with a fluorine-free dielectric layer. Concurrently, the exciton binding energy is increased with the addition of fluorinated groups, resulting in the decrease of phototransistor performance compared with less content of fluorinated groups due to the synergistic balance effect of fluorine functional groups. The results further clarify how the fluorine functional groups optimize the interface of organic phototransistors and modulate the photoelectric performance.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fluorinated Dielectrics‐Modulated Organic Phototransistors and Flexible Image Sensors

Jiang

Zheng

et al. 2022

Advanced Optical Materials

View full text Add to dashboard Cite

show abstract

“…1-Ethyl-3-methylimidazolium tetrafluoroborate ([EIM]BF 4 ) purchased from the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, was used as a testing liquid to develop the wetting ridge for supported thin PS films. Silicon(100) (Si) wafers were used as a substrate after being washed with a piranha solution at 393 K for 30 min. − By thorough rinsing with deionized water and nitrogen blow drying, the wafer surface was covered with a 2.2 nm oxide layer (Si/SiO x ) and exhibited a water contact angle θ of less than 10°.…”

Section: Experimental Sectionmentioning

confidence: 99%

Suppressed Chain Entanglement Induced by Thickness of Ultrathin Polystyrene Films

et al. 2021

Self Cite

View full text Add to dashboard Cite

The thickness effect on the relaxation behavior and chain entanglements was investigated for thin polystyrene films. By following the time evolution of the wetting ridge at the surface induced by a droplet of ionic liquid, the characteristic time (τ*) at which the ridge height started to change was obtained. Here, we demonstrated experimentally that the characteristic time was associated with the disentanglement time τ d , τ* ∼ τ d ∼ M w 3.4/Me 1.4, where Me denotes the entanglement molecular weight. The critical thickness (h c) at which τ* started to decrease was approximately 3.3R g. That is, the Me increased, or the interchain entanglement density decreased, as the film became thinner than the h c. This might be explained in terms of the conformational change from “spherical” to “ellipsoidal”, leading to a reduction in the pervaded volume (Vp ) of chains in the ultrathin films.

show abstract

“…However, the doping process in the fabrication of OFETs remains challenging mainly because of their instability due to the uncontrollable dopant diffusion and low doping efficiencies. To solve these issues, several approaches have been proposed in the past few years; these can be classified into the following two categories: (1) Direct doping of specially designed inorganic or organic dopants into polymer semiconductors (e.g., self-compensated doping with covalently bonded dopants to the backbone or solution-based doping over a limited depth − ) and (2) indirect doping by inducing polarization on the surfaces of dielectrics interfaced with polymer semiconductors (e.g., a self-assembled monolayer treatment with a specially designed functional group on the dielectric surface − or the use of a dielectric layer containing fluorinated functional groups − ).…”

Section: Introductionmentioning

confidence: 99%

Surface Polarization Doping in Diketopyrrolopyrrole-Based Conjugated Copolymers Using Cross-Linkable Terpolymer Dielectric Layers Containing Fluorinated Functional Units

Moon

Hwang

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

It is essential to tune the electrical properties of inorganic semiconductors via a doping process in the fabrication of cutting-edge electronic devices; however, the doping in organic field-effect transistors (OFETs) is limited by the uncontrollable dopant diffusion and low doping efficiencies. This study proposes the use of a fluorinated functional group in a polymer dielectric layer as an effective p-type doping strategy for ambipolar diketopyrrolopyrrole (DPP)-based donor−acceptor (D−A)-type semiconducting copolymer films used in OFETs, without generating structural perturbations. To experimentally verify the surface polarization doping effect of the fluorinated group, two terpolymerspoly(pentafluorostyrene-co-3-azidopropyl-methacrylate-copropargyl-methacrylate) (5F-SAPMA), wherein fluorinated units are included, and poly(phenyl-methacrylate-co-3-azidopropylmethacrylate-co-propargyl-methacrylate) (PhAPMA), without fluorinated unitsare designed and synthesized for use in OFETs. The synthesized 5F-SAPMA and PhAPMA films were cross-linked through the click reaction between the alkyne and azide units in the terpolymers at 150 °C to provide chemical, thermal, and mechanical stabilities and solvent resistance. The electrical characterization of the OFETs with the newly synthesized terpolymer dielectrics reveals that the surface polarization induced by the fluorinated groups of the 5F-SAPMA dielectrics leads to the generation of additional hole charges and helps minimize the broadening of the extended tail states in the vicinity of the valence band (highest occupied molecular orbital (HOMO) level). This not only enables a transition from the ambipolar to p-type dominant characteristics but also helps increase the hole mobility from 0.023 to 0.305 cm 2 /(V•s).

show abstract

Utilizing the Diffusion of Fluorinated Polymers to Modify the Semiconductor/Dielectric Interface in Solution-Processed Conjugated Polymer Field-Effect Transistors

Cited by 29 publications

References 70 publications

Fluorinated Dielectrics‐Modulated Organic Phototransistors and Flexible Image Sensors

Fluorinated Dielectrics‐Modulated Organic Phototransistors and Flexible Image Sensors

Suppressed Chain Entanglement Induced by Thickness of Ultrathin Polystyrene Films

Surface Polarization Doping in Diketopyrrolopyrrole-Based Conjugated Copolymers Using Cross-Linkable Terpolymer Dielectric Layers Containing Fluorinated Functional Units

Contact Info

Product

Resources

About