An organic electrochemical transistor of a multilayered porous semiconductor layer and a method of manufacturing the same

Abstract

The application discloses a kind of multilayer porous semiconductor layer organic electrochemical transistor and preparation method thereof, it is related to the field of flexible organic electrochemical transistor, the application includes substrate layer, electrode layer, semiconductor layer, ion gel layer, electrolyte layer and gate electrode from bottom to top in turn, the electrode layer includes source electrode and drain electrode, by the stacking of porous semiconductor film, form a kind of multilayer porous semiconductor layer, add ion gel layer to accelerate ion penetration speed, drop liquid electrolyte layer, utilize the electrolyte in electrolyte layer and the increased interface contact between ion gel layer realizes high permeability, to prepare organic electrochemical transistor with high transconductance, large drain current and low hysteresis, solve the shortcomings of the output current not ideal caused by insufficient contact between electrolyte layer and semiconductor layer, low permeability in electrochemical transistor and the problem of increased hysteresis caused by multilayer semiconductor layer stacking.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flexible organic electrochemical transistors, in particular to an organic electrochemical transistor with a multilayer porous semiconductor layer and a preparation method thereof. BACKGROUND

[0002] Conjugated polymers have been widely used due to their ability to conduct both electronic and ionic charge carriers, such as energy storage devices, electrochromic devices, neuromorphic computing, and bioelectronics. Organic electrochemical transistors (OECTs) take advantage of the electronic / ionic dual conductivity of conjugated polymers and have been highly anticipated in the field of bioelectronics, including recording electrical impulses of humans and cell populations, in vivo electrophysiological recordings, in vitro biosensing, and neuronal stimulation. Compared with traditional organic field-effect transistors (OFETs), one of the remarkable features of OECTs is the dependence on the transport of ions and charges (electrons / holes) to adjust the conductivity by electrochemically doping the semiconductor with electrolyte ions injected into the semiconductor channel through the gate voltage (V G ).

[0003] The organic electrochemical transistor device can be simply understood as a combination of an ionic circuit and an electronic circuit according to the Bernards model. The ionic circuit is in series with a resistor describing the flow of electrolyte ions and capacitors describing the storage of ions at the gate-electrolyte interface and in the channel volume along the gate-electrolyte-channel direction. The proportion of the gate voltage drop on the channel is controlled by the properties and geometry of the gate electrode. Using a non-polarized gate electrode such as Ag / AgCl, the pressure drop at the gate-electrolyte interface can be ignored. The electronic circuit is equivalent to a variable resistor affected by the ionic circuit along the source-channel-drain direction.

[0004] However, the existing problem is that the insufficient contact between the electrolyte layer and the semiconductor layer and the low permeability will result in an undesirable output current. SUMMARY

[0005] The present application aims to provide a stretchable organic electrochemical transistor with a multilayer porous semiconductor layer and a preparation method thereof, which solves the problem of insufficient contact between the electrolyte layer and the semiconductor layer and the low permeability resulting in an undesirable output current, and at the same time, uses an ionic gel layer to accelerate ion penetration / transmission to reduce the increase in hysteresis caused by the multilayer structure and improve the overall performance of the device.

[0006] The technical scheme adopted by the present application is as follows:

[0007] An organic electrochemical transistor of a multilayer porous semiconductor layer, from bottom to top, comprises a flexible substrate layer, an electrode layer, a multilayer porous semiconductor layer, an ionic gel layer, an electrolyte layer and a gate electrode; the electrode layer comprises a source electrode and a drain electrode; the multilayer porous semiconductor layer is composed of at least one porous solid semiconductor film.

[0008] Preferably, the material of the flexible substrate layer is at least one of SEBS, PDMS and PU.

[0009] Preferably, the manufacturing material of the electrode layer is gold, the thickness of the electrode layer ranges from 80 to 150 nm, and the material of the gate electrode is Ag / AgCl.

[0010] Preferably, the material of the multilayer porous semiconductor layer is a mixture of one of P3HT and Pg2T-T and SEBS, and the thickness of the film ranges from 200 to 300 nm.

[0011] Preferably, the material of the ionic gel layer is an ionic gel prepared by mixing a polymer and an ionic liquid, the polymer is one of PS-PMMA-PS, PS-PEO-PS, P(VDF-TrFE), P(VDF-HFP) and P(VDF-TrFE-CTFE), and the ionic liquid is at least one of [EMIM][TFSI], [EMIM][FSI], [EMIM][DCA], [BMIM][PF6] or [EMIM][BF4].

[0012] Preferably, the material of the electrolyte layer is an aqueous solution of a salt, and the aqueous solution of the salt is one of NaCl, KCl and PBS.

[0013] A preparation method of an organic electrochemical transistor of a multilayer porous semiconductor layer, for preparing an organic electrochemical transistor of a multilayer porous semiconductor layer, the preparation process comprises the following steps:

[0014] Step 1: clean the transparent glass substrate, and then dry it with nitrogen or heat dry it in a constant temperature oven for more than 6 hours;

[0015] Step 2: pour SEBS, PDMS or PU on the glass substrate coated with detergent, and then place it in a vacuum drying oven after the solution is leveled, to obtain a flexible substrate layer, and then peel off the flexible substrate layer from the glass substrate with a blade after drying;

[0016] Step 3: evaporate the electrode of gold with a thickness of 80 to 150 nm on the flexible substrate layer;

[0017] Step 4: clean the microscope glass slide, and then dry it with nitrogen or heat dry it in a constant temperature oven for more than 6 hours;

[0018] Step 5: spin coating the prepared dextran solution onto a microscope slide, and drying the spin-coated substrate to obtain a dextran sacrificial layer;

[0019] Step 6: spin coating the prepared P3HT mixed solution or Pg2T-T mixed solution onto the dextran sacrificial layer under a humidity of 88% RH;

[0020] Step 7: placing the substrate in a petri dish containing 40℃ deionized water, so that the dextran sacrificial layer dissolves in the deionized water to obtain a single-layer porous semiconductor layer;

[0021] Step 8: repeating steps 4-7 until three single-layer porous semiconductor layers are prepared, and then proceeding to step 9;

[0022] Step 9: transferring the three single-layer porous semiconductor layers in turn to a flexible substrate layer and blowing dry with nitrogen;

[0023] Step 10: coating an ionogel on the channel of the single-layer porous semiconductor layer;

[0024] Step 11: dropping an electrolyte on the channel of the single-layer porous semiconductor layer.

[0025] Preferably, in step 2, the drying temperature is 30℃ and the time is at least 24h; in step 5, the drying temperature is 110℃ and the time is at least 1 min.

[0026] Preferably, the drying method uses at least one of a constant temperature hot table heating, an oven heating and a hot air heating.

[0027] The beneficial effects of the present application are as follows:

[0028] 1. By simply stacking multiple layers of porous semiconductor films, the number of electrochemical doping reaction sites in the semiconductor can be effectively increased, the electrochemical doping of the electrolyte layer and the semiconductor layer can be strengthened, the output drain current of the device can be improved, and the input gate voltage control over the output can be enhanced.

[0029] 2. By adding an ionogel layer between the semiconductor layer and the electrolyte layer, the pre-wetting effect of the ionogel on the semiconductor layer is utilized to accelerate ion injection in the working state, which can effectively improve the hysteresis increase caused by the stacking of multiple semiconductor layers; at the same time, the addition of the ionogel layer enables some semiconductor polymer materials that need to work under ionic liquid electrolyte to work normally under salt aqueous solution electrolyte, which is more consistent with the application scenario of bioelectronics. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the proportional relationship of each component in the drawings of the present application does not represent the proportional relationship in actual material selection and design, and it is only a schematic diagram of structure or position, in which:

[0031] Figure 1 is a structural schematic diagram of the present application;

[0032] Figure 2 is a structural schematic diagram of the porous semiconductor layer 11 of the present application;

[0033] Figure 3 is a structural schematic diagram of the dense semiconductor thin film 22 of the present application;

[0034] Label explanation in the drawings:

[0035] 1-flexible substrate layer; 2-source electrode; 3-drain electrode; 4-gate electrode; 5-multilayer porous semiconductor layer; 6-ionic gel layer; 7-electrolyte layer; 11-porous semiconductor layer; 22-dense semiconductor thin film. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application, that is, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments.

[0037] The following will be combined Figures 1 to 3 to make a detailed description of the present application.

[0038] An organic electrochemical transistor of a multilayer porous semiconductor layer, from bottom to top, includes a flexible substrate layer, an electrode layer, a multilayer porous semiconductor layer, an ionic gel layer, an electrolyte layer and a gate electrode in sequence; the electrode layer includes a source electrode and a drain electrode; the multilayer porous semiconductor layer is composed of at least one porous semiconductor layer.

[0039] Example 1 (control group):

[0040] 1. Clean the transparent glass substrate with a surface roughness less than 1 nm, and heat dry in a constant temperature box for more than 6 h after cleaning;

[0041] 2. Apply a layer of dishwashing detergent on the glass substrate, pour PU on the glass substrate coated with dishwashing detergent, slightly vibrate, and then place in a vacuum drying oven for drying (30 ℃, 24 h). After drying, carefully peel off the flexible substrate from the glass substrate with a blade to obtain a PU substrate;

[0042] 3. The vacuum degree is 1x10 -4 Pa, and an electrode (80 nm) of gold is evaporated on a PU substrate;

[0043] 4. A microscope slide with a surface roughness less than 1 nm is cleaned, and after cleaning, is dried in a thermostat oven for more than 6 hours;

[0044] 5. The prepared dextran solution is spin-coated onto the microscope slide (3000 rpm, 60 s), and the spin-coated slide is dried (110 °C, 1 min) to obtain a dextran sacrificial layer;

[0045] 6. The prepared P3HT mixed solution (P3HT:SEBS = 2:1) is spin-coated onto the dextran sacrificial layer (5000 rpm, 10 s) under a humidity of less than 15% RH to obtain a P3HT thin film;

[0046] 7. The P3HT thin film is observed under SEM, and the observation shows that the P3HT thin film is flat and dense, and a dense semiconductor film 22 as shown in FIG. 2 is obtained; Figure 3

[0047] 8. The slide is placed in a culture dish containing deionized water, and the culture dish is placed on a hot stage (40 °C) to dissolve the dextran sacrificial layer in the deionized water to obtain a semiconductor active layer. One layer of the semiconductor active layer is transferred to a flexible substrate and dried with nitrogen;

[0048] 9. An electrolyte is dropped on the channel of the semiconductor active layer, and an Ag / AgCl gate electrode is inserted;

[0049] 10. Under test conditions: leakage voltage (V D ) = -0.5 V, gate voltage (V G ) scanning interval is 0.1~-1 V, PBS electrolyte is dropped on the semiconductor channel, and the forward scanning threshold voltage (V th-for ) = -0.56 V, the reverse scanning threshold voltage (V th-back ) = -0.68 V, the on-off ratio (I on / I off ) = 2x10 3 , the transconductance (g m ) = 0.45 mS, and the device is not easy to store for a long time without packaging and is damaged directly by stretching.

[0050] 11. After the device is stretched to 20% 300 times, the device thin film transconductance (g m ) = 0.04 mS, and the transconductance is retained by 8.89%.

[0051] ​Example 2:

[0052] 1. Clean the transparent glass substrate with a surface roughness of less than 1 nm, and then heat dry in a thermostat oven for more than 6 h;

[0053] 2. Apply a layer of dishwashing liquid on the glass substrate, pour PU onto the glass substrate coated with dishwashing liquid, slightly vibrate, and then flatten the solution. After flattening, place it in a vacuum drying oven for drying (30°C, 24 h). After drying, carefully peel off the flexible substrate from the glass substrate with a blade to obtain a PU substrate;

[0054] 3. Evaporate a gold electrode (80 nm) on the PU substrate under the condition of a vacuum degree of 1×10 -4 Pa;

[0055] 4. Clean the microscope glass slide with a surface roughness of less than 1 nm, and then heat dry in a thermostat oven for more than 6 h;

[0056] 5. Spin-coat the prepared dextran solution onto the microscope glass slide (3000 rpm, 60 s), and then dry the spin-coated glass slide (110°C, 1 min) to obtain a dextran sacrificial layer;

[0057] 6. Spin-coat the prepared P3HT mixed solution (P3HT:SEBS = 2:1) onto the dextran sacrificial layer under the condition of a humidity of 88% RH to obtain a P3HT thin film;

[0058] 7. Observe the P3HT thin film under SEM, and observe that the P3HT thin film has a plurality of pores uniformly distributed on the surface to obtain the porous semiconductor layer 11 shown in FIG. 1; Figure 2

[0059] 8. Place the glass slide in a culture dish containing deionized water, and place the culture dish on a hot stage (40°C) to dissolve the dextran sacrificial layer in the deionized water to obtain a semiconductor active layer. Transfer a layer of the semiconductor active layer to a flexible substrate, and dry with nitrogen;

[0060] 9. Drop the electrolyte on the channel of the semiconductor active layer, and insert the Ag / AgCl gate electrode;

[0061] 10. Test conditions: leakage voltage (V D ) = -0.5 V, gate voltage (V G ) scanning interval is 0.1~-1 V, drop PBS electrolyte above the semiconductor channel, and measure the forward scanning threshold voltage (V th-for ) = -0.48 V, and the reverse scanning threshold voltage (V th-back ) = -0.55 V, and the on-off ratio (I on ​ / I off = 2.3 × 10 3 Transconductance (g) m = 0.56 mS. If the device is not packaged, it is not easy to store for a long time and direct stretching will damage the device.

[0062] 11. The transconductance (g) of the thin film was measured after stretching the device to 30% for 300 cycles. m = 0.25mS, retaining 44.64% transconductance.

[0063] Example 3:

[0064] 1. Clean the transparent glass substrate with a surface roughness of less than 1 nm, and then dry it in a constant temperature oven for more than 6 hours;

[0065] 2. Apply a layer of detergent to the glass substrate, pour PU onto the glass substrate coated with detergent, gently shake to spread the solution evenly, and then place it in a vacuum drying oven to dry (30 ℃, 24 h). After drying, carefully peel the flexible substrate off the glass substrate with a blade to obtain the PU substrate.

[0066] 3. Vacuum degree is 1×10 -4 Under Pa conditions, gold electrodes (80 nm) were deposited onto a PU substrate by vapor deposition;

[0067] 4. Clean microscope slides with a surface roughness of less than 1 nm, and then dry them in a constant temperature oven for more than 6 hours.

[0068] 5. Spin-coat the prepared dextran solution onto a microscope slide (3000 rpm, 60 s), and then dry the spin-coated slide (110 ℃, 1 min) to obtain the dextran sacrificial layer;

[0069] 6. Under conditions of 88% RH, the prepared P3HT mixed solution (P3HT : SEBS = 2 : 1) was spin-coated onto the dextran sacrificial layer to obtain a P3HT film;

[0070] 7. Observation of the P3HT film under SEM revealed uniformly distributed pores on the surface of the P3HT film. Figure 2 The porous semiconductor layer 11 shown;

[0071] 8. Place the glass slide in a petri dish containing deionized water, and place the petri dish on a hot stage (40°C) to dissolve the dextran sacrificial layer in the deionized water to obtain a semiconductor active layer. Transfer one layer of semiconductor active layer onto a flexible substrate and dry it with nitrogen. Repeat the preparation process to transfer the second porous semiconductor layer onto the first porous semiconductor layer and dry it with nitrogen.

[0072] 9. Dropping electrolyte on the channel of the semiconductor active layer, inserting Ag / AgCl gate electrode;

[0073] 10. Under test conditions: leakage voltage (VD) = -0.5 V, gate voltage (VG) scanning interval is 0.1 ~ -1 V, dropping PBS electrolyte on the semiconductor channel, the forward scanning threshold voltage (V th-for ) = -0.46 V, the reverse scanning threshold voltage (V th-back ) = -0.56 V, the on-off ratio (I on / I off ) = 2.0×10 3 , transconductance (g m ) = 1.32 mS, if not packaged, the device is not easy to store for a long time and will be damaged directly by stretching.

[0074] 11. After the device is stretched to 30% 300 times, the device thin film transconductance (g m ) = 0.83 mS, retaining 62.88 % of the transconductance.

[0075] Example 4:

[0076] 1. Cleaning the transparent glass substrate with a surface roughness less than 1 nm, and drying in a constant temperature oven for more than 6 h after cleaning;

[0077] 2. Coating a layer of dishwashing detergent on the glass substrate, pouring PU on the glass substrate coated with dishwashing detergent, slightly vibrating, and spreading the solution, and then drying in a vacuum drying oven (30 ℃, 24 h) after spreading. After drying, the flexible substrate is carefully peeled off from the glass substrate with a blade to obtain a PU substrate;

[0078] 3. Evaporating a gold electrode (80 nm) on the PU substrate under the condition of a vacuum degree of 1×10 -4 Pa;

[0079] 4. Cleaning the microscope glass slide with a surface roughness less than 1 nm, and drying in a constant temperature oven for more than 6 h after cleaning;

[0080] 5. Spinning the prepared dextran solution onto the microscope glass slide (3000 rpm, 60 s), and drying the spun glass slide (110 ℃, 1 min) to obtain a dextran sacrificial layer;

[0081] 6. Spinning the prepared P3HT mixed solution (P3HT : SEBS = 2 : 1) onto the dextran sacrificial layer under the condition of 88% RH humidity to obtain a P3HT thin film;

[0082] 7. Observe the P3HT film under SEM, and observe that the P3HT film surface has uniformly distributed pores, and obtain Figure 2 the porous semiconductor layer 11 shown in FIG. 1;

[0083] 8. Place the glass slide in a culture dish containing deionized water, and place the culture dish on a hot stage (40°C) to dissolve the dextran sacrificial layer in the deionized water, and obtain the semiconductor active layer. Transfer a layer of the semiconductor active layer to a flexible substrate, and dry with nitrogen. Repeat the transfer of a second layer of the porous semiconductor layer to the first layer of the porous semiconductor layer, and dry with nitrogen. Repeat the transfer of a third layer of the porous semiconductor layer to the second layer of the porous semiconductor layer, and dry with nitrogen;

[0084] 9. Drop the electrolyte on the channel of the semiconductor active layer, and insert the Ag / AgCl gate electrode;

[0085] 10. Under the test conditions: leakage voltage (VD) = -0.5 V, and gate voltage (VG) scanning interval is 0.1~ -1 V, drop the PBS electrolyte on the semiconductor channel, and measure the forward scanning threshold voltage (V th-for ) = -0.44 V, the reverse scanning threshold voltage (V th-back ) = -0.62 V, the on-off ratio (I on / I off ) = 1.6×10 3 , and the transconductance (g m ) = 2.04 mS. If the device is not packaged, it is not easy to store for a long time, and direct stretching can damage the device.

[0086] 11. After the device is stretched to 30% 300 times, the device film thickness transconductance (g m ) = 1.63 mS, and the transconductance is retained by 79.90%.

[0087] Example 5:

[0088] 1. Wash the transparent glass substrate with a surface roughness of less than 1 nm, and heat dry the washed substrate in a constant temperature box for more than 6 h;

[0089] 2. Apply a layer of dishwashing liquid on the glass substrate, pour PU on the glass substrate coated with dishwashing liquid, slightly vibrate, and flatten the solution. After flattening, place the solution in a vacuum drying box and dry (30°C, 24 h). After drying, carefully peel the flexible substrate from the glass substrate with a blade to obtain a PU substrate;

[0090] 3. Evaporate the gold electrode (80 nm) on the PU substrate under the condition of a vacuum degree of 1×10 -4 Pa;

[0091] 4. The microscope slide with surface roughness less than 1 nm is cleaned, and then dried in a constant temperature oven for more than 6 hours;

[0092] 5. The prepared dextran solution is spin-coated on the microscope slide (3000 rpm, 60 s), and the spin-coated slide is dried (110 °C, 1 min) to obtain a dextran sacrificial layer;

[0093] 6. The prepared P3HT mixed solution (P3HT:SEBS = 2:1) is spin-coated on the dextran sacrificial layer under the condition of 88% RH to obtain a P3HT thin film;

[0094] 7. The P3HT thin film is observed under SEM, and the P3HT thin film with uniformly distributed pores is obtained, as shown in the porous semiconductor layer 11 in FIG. 1; Figure 2

[0095] 8. The slide is placed in a petri dish containing deionized water, and the petri dish is placed on a hot stage (40 °C) to dissolve the dextran sacrificial layer in the deionized water to obtain a semiconductor active layer. One layer of semiconductor active layer is transferred to a flexible substrate and dried with nitrogen;

[0096] 9. An ionic gel layer is applied on the channel of the semiconductor active layer, and after drying in a 40 °C vacuum drying oven, an electrolyte is dropped, and an Ag / AgCl gate electrode is inserted

[0097] 10. Under the test conditions: leakage voltage (V D ) = -0.5 V, gate voltage (V G ) scanning interval is 0.1~-1 V, PBS electrolyte is dropped above the semiconductor channel, the forward scanning threshold voltage (V th-for ) is measured to be -0.49 V, the reverse scanning threshold voltage (V th-back ) is measured to be -0.52 V, the on-off ratio (I on / I off ) is 2.2×10 3 , the transconductance (g m ) is 0.54 mS, and the device is not easy to store for a long time without packaging and will be damaged if directly stretched.

[0098] 11. After the device is stretched to 30% 300 times, the device thin film transconductance (g m ) is measured to be 0.24 mS, and the transconductance is retained by 44.44%.

[0099] Example 6:

[0100] ​1. Clean the transparent glass substrate with surface roughness less than 1 nm, and then heat dry in a thermostat oven for more than 6 hours;

[0101] 2. Apply a layer of dishwashing liquid on the glass substrate, pour PU on the glass substrate coated with dishwashing liquid, slightly vibrate, and then flatten the solution. After flattening, place the solution in a vacuum drying oven (30°C, 24 hours) for drying. After drying, carefully peel off the flexible substrate from the glass substrate with a blade to obtain a PU substrate;

[0102] 3. Evaporate a gold electrode (80 nm) on the PU substrate under the condition of a vacuum degree of 1×10 -4 Pa;

[0103] 4. Clean the microscope glass slide with surface roughness less than 1 nm, and then heat dry in a thermostat oven for more than 6 hours;

[0104] 5. Spin-coat the prepared dextran solution onto the microscope glass slide (3000 rpm, 60 seconds), and then dry the spin-coated glass slide (110°C, 1 minute) to obtain a dextran sacrificial layer;

[0105] 6. Spin-coat the prepared P3HT mixed solution (P3HT:SEBS = 2:1) onto the dextran sacrificial layer under the condition of a humidity of 88% RH to obtain a P3HT thin film;

[0106] 7. Observe the P3HT thin film under SEM, and observe that the P3HT thin film has uniformly distributed pores to obtain the porous semiconductor layer 11 shown in FIG. 1; Figure 2

[0107] 8. Place the glass slide in a culture dish containing deionized water, and place the culture dish on a hot stage (40°C) to dissolve the dextran sacrificial layer in the deionized water to obtain a semiconductor active layer. Transfer a layer of the semiconductor active layer to a flexible substrate, and dry with nitrogen. Repeat the preparation process to transfer a second layer of the porous semiconductor layer onto the first layer of the porous semiconductor layer, and dry with nitrogen;

[0108] 9. Apply an ionic gel layer on the channel of the semiconductor active layer, and then dry in a 40°C vacuum drying oven. After drying, drop the electrolyte, and insert the Ag / AgCl gate electrode

[0109] 10. Test conditions: leakage voltage (V D ) = -0.5 V, gate voltage (VG) scanning interval is 0.1~-1 V, drop PBS electrolyte above the semiconductor channel, and measure the forward scanning threshold voltage (V th-for ) = -0.46 V, and the reverse scanning threshold voltage (V th-back ​) = -0.50 V, on / off ratio (I on / I off ) = 1.7x10 3 , transconductance (g m ) = 1.68 mS, not easy to long-term storage without packaging device and directly stretchable damage device.

[0110] 11. After the device is stretched to 30% 300 times, the device film thickness transconductance (g m ) = 1.32 mS, 78.57 % of the transconductance is retained.

[0111] Example 7:

[0112] 1. The transparent glass substrate with a surface roughness less than 1 nm is cleaned, and after cleaning, it is dried in a thermostat oven for more than 6 h;

[0113] 2. A layer of dishwashing detergent is coated on the glass substrate, and PU is poured onto the glass substrate coated with dishwashing detergent, slightly vibrated, and the solution is leveled, and after leveling, it is placed in a vacuum drying oven for drying (30 ℃, 24 h), and after drying, the flexible substrate is carefully peeled off from the glass substrate with a blade to obtain a PU base;

[0114] 3. The gold electrode (80 nm) is evaporated on the PU substrate under the condition of vacuum degree 1x10 -4 Pa;

[0115] 4. The microscope slide with a surface roughness less than 1 nm is cleaned, and after cleaning, it is dried in a thermostat oven for more than 6 h;

[0116] 5. The prepared dextran solution is spin-coated onto the microscope slide (3000 rpm, 60 s), and the spin-coated slide is dried (110 ℃, 1 min) to obtain a dextran sacrificial layer;

[0117] 6. The prepared P3HT mixed solution (P3HT:SEBS = 2:1) is spin-coated onto the dextran sacrificial layer under the condition of 88% RH to obtain a P3HT thin film;

[0118] 7. The P3HT thin film is observed under SEM, and it is observed that the P3HT thin film surface has uniformly distributed pores to obtain the porous semiconductor layer 11 shown in FIG. 1; Figure 2

[0119] ​8. Put the glass slide into a culture dish containing deionized water, and place the culture dish on a hot stage (40 °C) to dissolve the dextran sacrificial layer in the deionized water, obtain a semiconductor active layer, transfer a layer of the semiconductor active layer to a flexible substrate, and dry with nitrogen, repeat the preparation process to transfer a second layer of the porous semiconductor layer to the first layer of the porous semiconductor layer, and dry with nitrogen, repeat the preparation process to transfer a third layer of the porous semiconductor layer to the second layer of the porous semiconductor layer, and dry with nitrogen;

[0120] 9. Apply an ionic gel layer on the channel of the semiconductor active layer, place it in a 40 °C vacuum drying oven to dry, then drop the electrolyte, and insert the Ag / AgCl gate electrode

[0121] 10. Under test conditions: leakage voltage (VD) = -0.5 V, gate voltage (VG) scanning interval is 0.1 ~ -1 V, drop PBS electrolyte on the semiconductor channel, measure the forward scanning threshold voltage (V th-for ) = -0.42 V, the reverse scanning threshold voltage (V th-back ) = -0.52 V, the on-off ratio (I on / I off ) = 0.9×10 3 , the transconductance (g m ) = 2.56 mS, if the device is not packaged, it is not easy to store for a long time and direct stretching will damage the device;

[0122] 11. After stretching the device to 30% 300 times, the device film thickness transconductance (g m ) = 2.03 mS, retaining 79.30% of the transconductance.

[0123] As can be seen from Examples 4-7, the organic electrochemical transistor according to the multi-layer porous semiconductor layer comprises, from bottom to top, a flexible substrate layer 1, an electrode layer, a semiconductor layer 5, an ionic gel layer 6, and an electrolyte layer 7; the electrode comprises a source electrode 2, a drain electrode 3, and a gate electrode 4; the source electrode 2 and the drain electrode 3 are provided above the multi-layer porous semiconductor layer 5, the multi-layer porous semiconductor layer 5 is provided above the ionic gel layer 6, the electrolyte layer 7 is provided below the gate electrode 4, and the multi-layer porous semiconductor layer 5 is provided; the multi-layer porous semiconductor layer 5 is a stretchable multi-layer porous solid semiconductor film prepared by spin coating and water transfer printing.

[0124] Compared with the electrochemical transistor prepared without treatment (i.e., the organic electrochemical transistor prepared in Example 1), the transconductance g mThe strain resistance and long-term stability of the whole device are improved. This is because the electrolyte dropped on the P3HT porous film penetrates into the porous semiconductor layer 11 as shown in Figure 2 Figure 2 The three-dimensional microstructure of the multilayer porous semiconductor layer is beneficial to increase the contact area between the electrolyte and the semiconductor. Under the modulation of the gate voltage, the electrolyte ions are more quickly injected into the semiconductor channel to regulate the drain current. The organic electrochemical transistor (i.e., the organic electrochemical transistor prepared in Examples 5-7) with the increased ionic gel layer accelerates the ion penetration speed by the pre-wetting of the ionic gel to the semiconductor layer, effectively improving the hysteresis increase caused by the multilayer structure. The stretchable electrochemical transistor not only has a certain mechanical strength, but is also physically, chemically and electrochemically stable, and can be used in the fields of flexible wear and bioelectronics.

[0125] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An organic electrochemical transistor with a multilayer porous semiconductor layer, characterized in that, From bottom to top, the structure includes a flexible substrate layer (1), an electrode layer, a multilayer porous semiconductor layer (5) obtained by mixing one of P3HT and Pg2T-T with SEBS, an ion gel layer (6), an aqueous solution of one of NaCl, KCl and PBS as an electrolyte layer (7), and a gate electrode (4); the electrode layer includes a source electrode (2) and a drain electrode (3); the multilayer porous semiconductor layer (5) is composed of at least one porous semiconductor thin film.

2. The organic electrochemical transistor with a multilayer porous semiconductor layer according to claim 1, characterized in that, The flexible substrate layer (1) is made of at least one of SEBS, PDMS and PU.

3. The organic electrochemical transistor with a multilayer porous semiconductor layer according to claim 1, characterized in that, The electrode layer is made of gold, and the thickness of the electrode layer is in the range of 80~150 nm. The gate electrode (4) is made of Ag / AgCl.

4. The organic electrochemical transistor with a multilayer porous semiconductor layer according to claim 1, characterized in that, The thickness of the multilayer porous semiconductor layer ranges from 200 to 300 nm.

5. The organic electrochemical transistor with a multilayer porous semiconductor layer according to claim 1, characterized in that, The material of the ionogel layer (6) is an ionogel prepared by mixing a polymer and an ion liquid. The polymer is one of PS-PMMA-PS, PS-PEO-PS, P(VDF-TrFE), P(VDF-HFP) and P(VDF-TrFE-CTFE). The ion liquid is at least one of [EMIM][TFSI], [EMIM][FSI], [EMIM][DCA], [BMIM][PF6] or [EMIM][BF4].

6. A method for fabricating an organic electrochemical transistor with a multilayer porous semiconductor layer, used to fabricate an organic electrochemical transistor with a multilayer porous semiconductor layer as described in any one of claims 1-5, characterized in that, The preparation process includes the following steps: Step 1: Clean the glass substrate, and then dry it with nitrogen or heat it in a constant temperature oven for more than 6 hours. Step 2: Pour SEBS, PDMS or PU onto a glass substrate coated with detergent. After the solution is spread evenly, place it in a vacuum drying oven to dry and obtain a flexible substrate layer (1). After drying, peel the flexible substrate layer (1) off the glass substrate with a blade. Step 3: Deposit gold electrodes with a thickness of 80~150nm onto the flexible substrate layer (1); Step 4: Clean the microscope slides, and then dry them with nitrogen or in a constant temperature oven for more than 6 hours. Step 5: Spin-coat the prepared dextran solution onto a microscope slide to obtain a substrate, and then dry the substrate to obtain a dextran sacrificial layer; Step 6: Under conditions of 88% RH, spin-coat the prepared P3HT and SEBS mixed solution or Pg2T-T and SEBS mixed solution onto the dextran sacrificial layer; Step 7: Place the substrate in a petri dish containing 40 °C deionized water to dissolve the dextran sacrificial layer in the deionized water, thus obtaining a single-layer porous semiconductor layer; Step 8: Repeat steps 4-7 until three single-layer porous semiconductor layers are obtained; Step 9: Transfer the three-layer single-layer porous semiconductor layer sequentially onto the flexible substrate layer (1) and dry it with nitrogen gas; Step 10: Coat the channel of the 3-layer monolayer porous semiconductor layer with ion gel; Step 11: Drop electrolyte onto the channel of the 3-layer monolayer porous semiconductor layer.

7. The method for fabricating a multilayer porous semiconductor organic electrochemical transistor according to claim 6, characterized in that, In step 2, the drying temperature is 30 ℃ and the time is at least 24 hours; in step 5, the drying temperature is 110 ℃ and the time is at least 1 minute.

8. The method for fabricating a multilayer porous semiconductor organic electrochemical transistor according to claim 6, characterized in that, The drying method employs at least one of the following: constant temperature hot table heating, oven heating, and hot air heating.

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