Stretchable organic field effect transistor based on double dielectric layers and preparation and application thereof
By adopting a dual-layer dielectric layer structure and semiconductor polymer/elastic blend design in stretchable organic field effect transistors, the problems of high power consumption and inappropriate wearable technology are solved, and the low power consumption and excellent performance OFETs are achieved.
Patent Information
- Application Number
- CN202411886832.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-05-02
AI Technical Summary
Existing stretchable organic field effect transistors (OFETs) consume high power at high operating voltages, resulting in increased temperature and shortened device life, and are not suitable for wearable technology applications.
A double-layer dielectric layer structure is adopted, wherein the lower layer is a polymer elastomer layer and the upper layer is an ionic gel layer. Combining a blend of semiconductor polymer and elastomer as an active layer, an OFET with excellent tensile properties and low power consumption is formed.
The OFET that maintains normal operation and stable performance at low voltages has excellent transfer characteristics and low leakage current, which significantly reduces operating voltage and power consumption, and is suitable for wearable devices.
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Figure CN119923065A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of preparation of stretchable organic field effect transistors, and specifically relates to a stretchable organic field effect transistor based on a double-layer dielectric layer and its preparation and application. Background Art
[0002] Stretchable organic field-effect transistors (OFETs) have a wide range of application demands in flexible displays, flexible sensors, and wearable devices. In order to achieve the stretchability of OFETs, the dielectric layer must be stretchable. Today, only a few polymer dielectrics (thermoplastic polyurethane (TPU), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), and polydimethylsiloxane (PDMS)) can adapt to strain and maintain stable electrical properties. However, these polymers are gate dielectric materials with fairly low surface capacitance, and the operating voltage of the device is usually as high as tens or even more than a hundred volts, which leads to high power consumption. Power consumption generates heat energy, leading to increased temperature, which in turn shortens the life of organic devices. More importantly, considering the current battery capacity and safety risks, the high operating voltage of OFETs is not suitable for wearable technology. Therefore, stretchable OFETs with low power consumption remain a major challenge that limits their practical applications.
[0003] Recently, electrolyte-gated transistors based on ion gels have attracted much attention. Ion gels are prepared by physical crosslinking of block copolymers or chemical crosslinking of monomers in ionic liquids. The advantages of using ion gels as gate dielectrics include high ionic conductivity, large surface capacitance, and excellent stretchability. When a voltage is applied to the gate, the ions in the ion gel migrate and accumulate at the gate-electrolyte and semiconductor-electrolyte interfaces respectively under an electrostatic mechanism to form a dense electric double layer (EDL). The EDL formed at these two interfaces acts as a capacitor with an extremely small spacing (about 1 nm) and produces a high unit surface capacitance (>1 μF / cm 2 ). Therefore, at a relatively low voltage, an extremely high density of charge carriers can be introduced at the interface of the semiconductor channel. Although ion gels have significant advantages over traditional insulating elastomers as gate dielectrics, they are usually accompanied by a non-negligible large leakage current, which leads to a significant increase in static power consumption, greatly limiting the widespread application of ion gel dielectric layers in OFET devices. Summary of the invention
[0004] In order to solve the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a stretchable organic field effect transistor based on a double-layer dielectric layer.
[0005] Another object of the present invention is to provide a method for preparing the above-mentioned stretchable organic field effect transistor based on a double-layer dielectric layer.
[0006] Another object of the present invention is to provide an application of the above-mentioned stretchable organic field effect transistor based on a double-layer dielectric layer.
[0007] The purpose of the present invention is achieved through the following technical solutions:
[0008] A stretchable organic field effect transistor based on a double dielectric layer, the structure of which comprises, from bottom to top, a stretchable substrate, a stretchable gate, a double dielectric layer, a stretchable active layer and a stretchable source / drain electrode;
[0009] The lower layer of the double dielectric layer is a polymer elastomer layer, i.e., the first dielectric layer;
[0010] The upper layer of the double dielectric layer is an ion gel layer, that is, the second dielectric layer.
[0011] Preferably, the raw material of the stretchable substrate is one of thermoplastic polyurethane (TPU), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS) and polydimethylsiloxane (PMDS).
[0012] Preferably, the thickness of the stretchable substrate is 100 to 1000 μm; more preferably, it is 200 to 1000 μm.
[0013] Preferably, the raw materials of the stretchable gate and the stretchable source / drain electrodes are at least one of silver nanowires (AgNWs), carbon nanotubes (CNTs) and carbon nanofibers (CNFs).
[0014] Preferably, the thickness of the stretchable gate is 50 to 5000 nm, more preferably 100 to 500 nm; the thickness of the stretchable source / drain electrode is 50 to 5000 nm, more preferably 100 to 500 nm.
[0015] Preferably, the polymer elastomer of the first dielectric layer is one of thermoplastic polyurethane (TPU) and polyvinylidene fluoride-trifluoroethylene (PVDF-HFP).
[0016] Preferably, the thickness of the first dielectric layer (polymer elastomer layer) is 10 to 150 μm; more preferably, 20 to 150 μm.
[0017] Preferably, the ion gel is obtained by mixing an ionic liquid and a polymer elastomer in a mass ratio of 1:2 to 1:5; the ionic liquid is one of 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTF]), 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][N(CN)2]), 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTF]); and the polymer elastomer is one of thermoplastic polyurethane (TPU) and polyvinylidene fluoride-trifluoroethylene (PVDF-HFP).
[0018] Preferably, the second dielectric layer (ion gel layer) has a thickness of 10-30 μm.
[0019] Preferably, the stretchable active layer is a semiconductor polymer / elastomer blend, wherein the mass ratio of the semiconductor polymer to the elastomer is 1:99 to 3:1, more preferably 1:10 to 1:1; the semiconductor polymer is one of poly(3-hexylthiophene) (P3HT) and naphthalene diimide-bithiophene alternating copolymer (N2200); the elastomer is one of hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS) and polydimethylsiloxane (PMDS).
[0020] Preferably, the thickness of the stretchable active layer is 30 to 100 nm; more preferably, 30 to 50 nm.
[0021] The above-mentioned method for preparing a stretchable organic field effect transistor based on a double-layer dielectric layer comprises the following steps:
[0022] (1) preparing a stretchable substrate on a substrate having a sacrificial layer, and after drying, preparing a stretchable gate on the stretchable substrate;
[0023] (2) preparing a polymer elastomer layer on the stretchable gate as a first dielectric layer, preparing an ion gel layer on the first dielectric layer as a second dielectric layer, and combining the first dielectric layer and the second dielectric layer into a double dielectric layer;
[0024] (3) A stretchable active layer is prepared on the double-layer dielectric layer, and then a stretchable source / drain electrode is prepared on the stretchable active layer, and the sacrificial layer is removed to obtain a stretchable organic field effect transistor based on the double-layer dielectric layer.
[0025] Preferably, the stretchable substrate in step (1) is obtained by spin coating a layer of elastomer solution on a substrate having a sacrificial layer and drying; the elastomer is one of thermoplastic polyurethane (TPU), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS) and polydimethylsiloxane (PMDS).
[0026] Preferably, the thickness of the stretchable substrate in step (1) is 100 to 1000 μm; more preferably, it is 200 to 1000 μm.
[0027] Preferably, the stretchable gate in step (1) is obtained by spraying a layer of stretchable electrode material suspension on a stretchable substrate and drying it; the stretchable electrode material is at least one of silver nanowires (AgNWs), carbon nanotubes (CNTs) and carbon nanofibers (CNFs).
[0028] Preferably, the thickness of the stretchable gate in step (1) is 50 to 5000 nm; more preferably, 100 to 500 nm.
[0029] Preferably, the polymer elastomer layer in step (2) is obtained by scraping a layer of polymer elastomer on the stretchable gate electrode and drying it; the polymer elastomer is one of thermoplastic polyurethane (TPU) and polyvinylidene fluoride-trifluoroethylene (PVDF-HFP).
[0030] Preferably, the thickness of the polymer elastomer layer in step (2) is 10 to 150 μm; more preferably, 20 to 150 μm.
[0031] Preferably, the ion gel layer in step (2) is obtained by scraping a layer of ion gel on the polymer elastomer layer and drying; the ion gel is obtained by mixing an ionic liquid and a polymer elastomer in a mass ratio of 1:2 to 1:5; the ionic liquid is one of 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTF]), 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][N(CN)2]), 1-ethyl-3-methylimidazolium dicyanamide ([EMIM][DCA]) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTF]); and the polymer elastomer is one of thermoplastic polyurethane (TPU) and polyvinylidene fluoride-trifluoroethylene (PVDF-HFP).
[0032] Preferably, the thickness of the ion gel layer in step (2) is 10 to 30 μm.
[0033] Preferably, the stretchable active layer in step (3) is obtained by spin coating a semiconductor polymer / elastomer blend solution on the ion gel layer and drying; the semiconductor polymer is one of poly(3-hexylthiophene) (P3HT) and naphthalene diimide-bithiophene alternating copolymer (N2200); and the elastomer is one of hydrogenated styrene-butadiene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS) and polydimethylsiloxane (PMDS).
[0034] The mass ratio of the semiconductor polymer to the elastomer in the semiconductor polymer / elastomer blend solution is 1:99 to 3:1, and more preferably 1:10 to 1:1.
[0035] Preferably, the thickness of the stretchable active layer in step (3) is 30 to 100 nm; more preferably, 30 to 50 nm.
[0036] Preferably, the stretchable source / drain electrode in step (3) is obtained by spraying a layer of stretchable electrode material suspension on the stretchable active layer and drying; the stretchable electrode material is at least one of silver nanowires (AgNWs), carbon nanotubes (CNTs) and carbon nanofibers (CNFs).
[0037] Preferably, the thickness of the stretchable source / drain electrode in step (3) is 50 to 5000 nm; more preferably, 100 to 500 nm.
[0038] The above-mentioned application of a stretchable organic field effect transistor based on a double-layer dielectric layer.
[0039] Preferably, the stretchable organic field effect transistor based on the double dielectric layer is used in the wearable field.
[0040] Preferably, the stretchable organic field effect transistor based on the double dielectric layer is used in active display, sensing, and logic circuits.
[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0042] (1) The stretchable organic field effect transistor with a double dielectric layer obtained by the present invention can maintain normal operation and relatively stable performance under 10% stretching, and the active layer can still maintain an intact surface morphology even after being stretched and released 100 times under 50% strain.
[0043] (2) The stretchable organic field effect transistor with a double dielectric layer obtained by the present invention not only has excellent transfer characteristics, but also exhibits a low leakage current; the double dielectric layer with a micron-level thickness has a unit area capacitance of the order of μF / cm, and a leakage current of less than 1μA, which significantly reduces the operating voltage of the organic field effect transistor and increases the on-state current.
[0044] (3) The ion gel in the double dielectric layer prepared by the present invention provides a large capacitance, and the elastomer in the double dielectric layer can reduce the leakage current of the device, thereby realizing an organic field effect transistor with complementary low power consumption and high stability. Since all functional layers have good stretchability, the double dielectric layer organic field effect transistor prepared by the present invention has the characteristics of excellent electrical performance and good stretchability.
[0045] (4) The stretchable organic field-effect transistor based on the double-layer dielectric layer prepared by the present invention has broad application prospects in the wearable field; among them, it has a wide range of applications in active display, sensing, and logic circuits. BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Figure 1 The following is a flow chart of the preparation of the embodiment.
[0047] Figure 2 This is a graph of unit surface capacitance-frequency of the double-layer dielectric layer in Example 4.
[0048] Figure 3 This is a digital photo of the active layer stretched by 50% in Example 2 and the transfer characteristic curve of the organic field effect transistor.
[0049] Figure 4 1 and 2 are the transfer characteristic curves and the corresponding leakage current curves of the organic field effect transistor based on the double dielectric layer in Example 3.
[0050] Figure 5 This is a performance comparison diagram of the field effect transistor of Example 1 in the initial state, and after being stretched 10% along the channel direction and in the direction perpendicular to the channel.
[0051] Figure 6 1 is the leakage current curve of the organic field effect transistor based on a single dielectric layer in Comparative Example 1.
[0052] Figure 7 1 is the transfer characteristic curve of the organic field effect transistor based on a single dielectric layer in Comparative Example 2. DETAILED DESCRIPTION
[0053] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.
[0054] If no specific conditions are specified in the examples of the present invention, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. All raw materials, reagents, etc. used without specifying the manufacturer are conventional products that can be purchased commercially.
[0055] Example 1
[0056] (1) A layer of TPU solution was spin-coated on a glass sheet with a sacrificial layer to prepare a 200 μm thick stretchable substrate. After it dried to form a film, a suspension of AgNWs was sprayed on the TPU film to prepare a 500 nm thick gate electrode.
[0057] (2) A 150 μm thick TPU layer was scraped on the AgNWs gate electrode as the lower dielectric layer; after it dried to form a film, a 30 μm thick [EMIM][BF4] / TPU ion gel layer was scraped as the upper dielectric layer. The mass ratio of [EMIM][BF4]:TPU in the ion gel solution was 1:2.
[0058] (3) Spin-coat a P3HT / SEBS blend solution on the dried ion gel layer as an active layer, where the mass ratio of P3HT to SEBS is 1:1 and the thickness of the active layer is 50 nm; after drying to form a film, spray a CNTs suspension to prepare a 100 nm thick source / drain electrode. Finally, remove the sacrificial layer to obtain a stretchable organic field-effect transistor.
[0059] The process of preparing the stretchable organic field effect transistor based on the double dielectric layer obtained in this embodiment is as follows: Figure 1 As shown, it can be seen that the device structure is a bottom gate top contact structure. Figure 5 Figure 2 is the transfer characteristic curve of the organic field effect transistor under different stretching states. It can be seen that the organic field effect transistor can maintain normal operation and relatively stable performance under 10% stretching.
[0060] Example 2
[0061] (1) A TPU solution was spin-coated on a glass sheet with a sacrificial layer to prepare a 500 μm thick stretchable substrate. After it dried to form a film, a CNTs suspension was sprayed on the TPU film to prepare a 200 nm thick gate electrode.
[0062] (2) A 100 μm thick TPU layer was scraped on the CNTs gate electrode as the lower dielectric layer; after it dried to form a film, a 10 μm thick [EMIM][OTF] / TPU ion gel layer was scraped as the upper dielectric layer, and the mass ratio of [EMIM][OTF]:TPU in the ion gel solution was 1:5.
[0063] (3) Spin-coat a layer of P3HT / SEBS blend solution on the dried ion gel layer as an active layer, where the mass ratio of P3HT to SEBS is 1:4 and the thickness of the active layer is 30 nm; after drying to form a film, spray CNFs suspension to prepare 100 nm thick source / drain electrodes. Finally, remove the sacrificial layer to obtain a stretchable organic field-effect transistor.
[0064] The stretching of the P3HT / SEBS blended film of the organic field effect transistor active layer obtained in this example is as follows: Figure 3 As shown in a, it can be seen that the P3HT / SEBS blend film can maintain a good surface morphology even after being stretched and released 100 times under 50% strain. The semiconductor P3HT aggregates in the blend film are infiltrated in the SEBS elastomer, and the SEBS on the surface can well protect P3HT and enhance the environmental stability of the device. More importantly, the network structure formed by the P3HT embedded in the elastomer matrix can enhance the mechanical stretchability of the P3HT semiconductor polymer while maintaining its electrical properties. In addition, Figure 3 The transfer characteristic curve of the device in b shows that the on-state current of the device is 4.8×10 -5 A.
[0065] Example 3
[0066] (1) SEBS solution was spin-coated on a glass sheet with a sacrificial layer to prepare a 1000 μm thick stretchable substrate. After it dried to form a film, a CNFs suspension was sprayed on the SEBS film to prepare a 300 nm thick gate electrode.
[0067] (2) A 20 μm thick PVDF-HFP layer was scraped on the CNFs gate electrode as the lower dielectric layer; after it dried to form a film, a 10 μm thick [EMIM][TFSI] / PVDF-HFP ion gel layer was scraped as the upper dielectric layer. The mass ratio of [EMIM][TFSI]:PVDF-HFP in the ion gel solution was 1:4.
[0068] (3) Spin-coat a layer of P3HT / PDMS blend solution on the dried ion gel layer as an active layer, where the mass ratio of P3HT to PDMS is 1:9 and the thickness of the active layer is 50 nm; after drying to form a film, spray CNTs suspension to prepare 500 nm thick source / drain electrodes. Finally, remove the sacrificial layer to obtain a stretchable organic field-effect transistor.
[0069] The electrical properties of the stretchable organic field effect transistor based on the double dielectric layer obtained in this embodiment are as follows: Figure 4As shown in the figure, it can be seen that when PVDF-HFP+[EMIM][TFSI] / PVDF-HFP is used as the dielectric layer, the device not only has excellent transfer characteristics but also exhibits low leakage current. The on-state current of the device is 7.8×10 -5 A, current switching ratio is 10 4 , at the maximum operating voltage, the leakage current is less than 5×10 -7 A.
[0070] Example 4
[0071] (1) A TPU solution was spin-coated on a glass sheet with a sacrificial layer to prepare a 200 μm thick stretchable substrate. After it dried to form a film, a layer of AgNWs suspension was sprayed on the TPU film to prepare a 200 nm thick gate electrode.
[0072] (2) A 50 μm thick TPU layer was scraped on the AgNWs gate electrode as the lower dielectric layer; after it dried to form a film, a 20 μm thick [EMIM][DCA] / TPU ion gel layer was scraped as the upper dielectric layer. The mass ratio of [EMIM][DCA]:TPU in the ion gel solution was 1:3.
[0073] (3) Spin-coat a layer of N2200 / PDMS blend solution on the dried ion gel layer as an active layer, where the mass ratio of N2200 to PDMS is 1:2 and the thickness of the active layer is 50 nm; after drying to form a film, spray CNFs suspension to prepare 100 nm thick source / drain electrodes. Finally, remove the sacrificial layer to obtain a stretchable organic field-effect transistor.
[0074] The capacitance performance test of the double dielectric layer TPU+[EMIM][DCA] / TPU obtained in this embodiment is as follows: Figure 2 As shown, it can be seen that the double-layer dielectric layer with a thickness of micron level has a unit area capacitance of the order of μF / cm, which can significantly reduce the operating voltage of the organic field effect transistor and increase the on-state current.
[0075] Comparative Example 1
[0076] (1) SEBS solution was spin-coated on a glass sheet with a sacrificial layer to prepare a 1000 μm thick stretchable substrate. After it dried to form a film, a CNFs suspension was sprayed on the SEBS film to prepare a 300 nm thick gate electrode.
[0077] (2) A 10 μm thick [EMIM][TFSI] / PVDF-HFP ion gel layer was scraped onto the CNFs gate electrode as a dielectric layer. The mass ratio of [EMIM][TFSI]:PVDF-HFP in the ion gel solution was 1:4.
[0078] (3) Spin-coat a layer of P3HT / PDMS blend solution on the dried ion gel layer as an active layer, where the mass ratio of P3HT to PDMS is 1:9 and the thickness of the active layer is 50 nm; after drying to form a film, spray CNTs suspension to prepare 500 nm thick source / drain electrodes. Finally, remove the sacrificial layer to obtain a stretchable organic field-effect transistor.
[0079] The leakage current of the stretchable organic field effect transistor based on the single-layer [EMIM][TFSI] / PVDF-HFP dielectric layer obtained in this comparative example is as follows: Figure 6 As shown in the figure, compared with Example 3, the lower layer of PVDF-HFP is missing, and it can be seen that the leakage current of the organic field effect transistor is greater than 10 -4 A, the leakage current in the device is very high. This will have a negative impact on the electrical performance of the device (such as heating, unstable output voltage, etc.), and may even cause the dielectric layer to break down.
[0080] Comparative Example 2
[0081] (1) A TPU solution was spin-coated on a glass sheet with a sacrificial layer to prepare a 500 μm thick stretchable substrate. After it dried to form a film, a CNTs suspension was sprayed on the TPU film to prepare a 200 nm thick gate electrode.
[0082] (2) A 100 μm thick TPU was scraped onto the CNTs gate electrode as a dielectric layer.
[0083] (3) Spin-coat a layer of P3HT / SEBS blend solution on the dried ion gel layer as an active layer, where the mass ratio of P3HT to SEBS is 1:4 and the thickness of the active layer is 30 nm; after drying to form a film, spray CNFs suspension to prepare 100 nm thick source / drain electrodes. Finally, remove the sacrificial layer to obtain a stretchable organic field-effect transistor.
[0084] The transfer characteristic curve of the stretchable organic field effect transistor based on the single-layer TPU dielectric layer obtained in this comparative example is as follows: Figure 7 As shown in the figure, it can be seen that compared with Example 2, the absence of the ion gel layer not only increases the operating voltage of the organic field effect transistor to 60 V, but also reduces the on-state current to 6.4×10 -7 A. The device has poor performance and high power consumption, which causes gradual degradation of the organic materials and shortens the device life.
[0085] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.
Claims
1. A stretchable organic field effect transistor based on a double dielectric layer, characterized in that: Its structure includes, from bottom to top, a stretchable substrate, a stretchable gate, a double-layer dielectric layer, a stretchable active layer and a stretchable source / drain electrode; The lower layer of the double dielectric layer is a polymer elastomer layer, i.e., the first dielectric layer; The upper layer of the double dielectric layer is an ion gel layer, that is, the second dielectric layer.
2. A stretchable organic field effect transistor based on a double dielectric layer according to claim 1, characterized in that: The thickness of the first dielectric layer is 10 to 150 μm; The polymer elastomer is one of thermoplastic polyurethane and polyvinylidene fluoride-trifluoroethylene.
3. A stretchable organic field effect transistor based on a double dielectric layer according to claim 1 or 2, characterized in that: The ion gel is obtained by mixing an ionic liquid and a polymer elastomer in a mass ratio of 1:2 to 1:5; The ionic liquid is one of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium dicyanamide and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; the polymer elastomer is one of thermoplastic polyurethane and polyvinylidene fluoride-trifluoroethylene; The thickness of the second dielectric layer is 10-30 μm.
4. A stretchable organic field effect transistor based on a double dielectric layer according to claim 1 or 2, characterized in that: The stretchable active layer is a semiconductor polymer / elastomer blend, wherein the mass ratio of the semiconductor polymer to the elastomer is 1:99 to 3:1; the semiconductor polymer is one of poly(3-hexylthiophene) and naphthalene diimide-bithiophene alternating copolymer; the elastomer is one of hydrogenated styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer and polydimethylsiloxane; The thickness of the stretchable active layer is 30 to 100 nm; The materials of the stretchable gate and the stretchable source / drain electrodes are at least one of silver nanowires, carbon nanotubes and carbon nanofibers; The thickness of the stretchable gate is 50 to 5000 nm; the thickness of the stretchable source / drain electrode is 50 to 5000 nm; The raw material of the stretchable substrate is one of thermoplastic polyurethane, hydrogenated styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer and polydimethylsiloxane; The thickness of the stretchable substrate is 100-1000 μm.
5. A method for preparing a stretchable organic field effect transistor based on a double dielectric layer according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) preparing a stretchable substrate on a substrate having a sacrificial layer, and after drying, preparing a stretchable gate on the stretchable substrate; (2) preparing a polymer elastomer layer on the stretchable gate as a first dielectric layer, preparing an ion gel layer on the first dielectric layer as a second dielectric layer, and combining the first dielectric layer and the second dielectric layer into a double dielectric layer; (3) A stretchable active layer is prepared on the double-layer dielectric layer, and then a stretchable source / drain electrode is prepared on the stretchable active layer, and the sacrificial layer is removed to obtain a stretchable organic field effect transistor based on the double-layer dielectric layer.
6. The preparation method according to claim 5, characterized in that: The polymer elastomer layer in step (2) is obtained by coating a layer of polymer elastomer on the stretchable gate electrode and drying the layer; the polymer elastomer is one of thermoplastic polyurethane and polyvinylidene fluoride-trifluoroethylene; The thickness of the polymer elastomer layer in step (2) is 10 to 150 μm.
7. The preparation method according to claim 5 or 6, characterized in that: The ion gel layer in step (2) is obtained by scraping a layer of ion gel on the polymer elastomer layer and drying; The ion gel is obtained by mixing an ionic liquid and a polymer elastomer in a mass ratio of 1:2 to 1:5; the ionic liquid is one of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium dicyanamide and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; the polymer elastomer is one of thermoplastic polyurethane and polyvinylidene fluoride-trifluoroethylene; The thickness of the ion gel layer in step (2) is 10 to 30 μm.
8. The preparation method according to claim 5 or 6, characterized in that: The stretchable active layer in step (3) is obtained by spin coating a semiconductor polymer / elastomer blend solution on the ion gel layer and drying; the semiconductor polymer is one of poly(3-hexylthiophene) and naphthalene diimide-bithiophene alternating copolymer; the elastomer is one of hydrogenated styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer and polydimethylsiloxane; The mass ratio of the semiconductor polymer to the elastomer in the semiconductor polymer / elastomer blend solution is 1:99 to 3:1; The thickness of the stretchable active layer in step (3) is 30 to 100 nm; The stretchable source / drain electrode in step (3) is obtained by spraying a layer of a stretchable electrode material suspension on the stretchable active layer and drying the suspension; the stretchable electrode material is at least one of silver nanowires, carbon nanotubes and carbon nanofibers; The thickness of the stretchable source / drain electrode in step (3) is 50 to 5000 nm.
9. The preparation method according to claim 5 or 6, characterized in that: The stretchable substrate in step (1) is obtained by spin coating a layer of elastomer solution on a substrate having a sacrificial layer and drying the elastomer; the elastomer is one of thermoplastic polyurethane, hydrogenated styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer and polydimethylsiloxane; The thickness of the stretchable substrate in step (1) is 100 to 1000 μm; The stretchable gate in step (1) is obtained by spraying a layer of a stretchable electrode material suspension on a stretchable substrate and drying the suspension; the stretchable electrode material is at least one of silver nanowires, carbon nanotubes and carbon nanofibers; The thickness of the stretchable gate in step (1) is 50 to 5000 nm.
10. Application of the stretchable organic field effect transistor based on a double dielectric layer as described in any one of claims 1 to 4 in the wearable field.