An organic field effect transistor and a preparation method and application thereof
By combining upconversion quantum dots and organic active layers, the shortcomings of organic field-effect transistors in near-infrared light response are addressed, improving their absorption performance for near-infrared light and achieving high-efficiency computing and stability, making them suitable for intelligent dynamic image recognition systems.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN UNIV
- Filing Date
- 2024-10-30
- Publication Date
- 2026-05-12
AI Technical Summary
Existing organic field-effect transistors lack near-infrared light response, and the traditional von Neumann computing architecture results in low computing efficiency and high power consumption.
The structure combines upconversion quantum dots with an organic active layer. The quantum dot layer material is NaGdF4:Yb/Er, LaF3:Yb/Ho, or LaF3:Yb/Er, with a thickness of 5-20 nm. The organic active layer material is poly(3-hexylthiophene), pentacene, or tetraacene, with a thickness of 30-50 nm. The quantum dot layer and the organic active layer are formed by spin coating and annealing, and source and drain electrodes are deposited on the surface of the organic active layer.
It improves the response performance of organic field-effect transistors to near-infrared light, achieving high-efficiency computing and excellent stability, and is suitable for intelligent dynamic image recognition systems.
Smart Images
Figure CN119486460B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic science and technology, and in particular to an organic field-effect transistor, its fabrication method, and its application. Background Technology
[0002] Advanced artificial vision systems play an indispensable role in cutting-edge applications such as smart homes, autonomous vehicles, and dynamic trajectory analysis. These systems are typically built on complementary metal-oxide-semiconductor (CMOS) platforms, which integrate multiple components: image sensors specifically designed to capture visual input, memory to store critical information, and processors responsible for performing complex calculations. However, with the rapid growth of visual data, the traditional von Neumann computer architecture's separation of processor and memory units has become a bottleneck limiting computational efficiency, introducing transmission latency and high power consumption, and is gradually failing to keep pace with the processing of massive amounts of data in the era of big data.
[0003] However, the light absorption characteristics of organic materials are generally limited to the visible and ultraviolet light regions, with weak absorption capabilities for near-infrared light. Therefore, field-effect transistors based on organic materials have inherent limitations in their near-infrared light response. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide an organic field-effect transistor, its fabrication method and application, aiming to solve the problem of the lack of near-infrared light response in existing organic field-effect transistors.
[0005] The technical solution of the present invention is as follows:
[0006] In a first aspect, the present invention provides an organic field-effect transistor, wherein the structure of the organic field-effect transistor, from bottom to top, comprises a substrate, a gate electrode, a quantum dot layer, an organic active layer, and source / drain electrodes.
[0007] The quantum dot layer is made of upconversion quantum dots.
[0008] Preferably, the thickness of the quantum dot layer is 5-20 nm, and the material used for the quantum dot layer is one or more of NaGdF4:Yb / Er, LaF3:Yb / Ho, and LaF3:Yb / Er.
[0009] Preferably, the thickness of the organic active layer is 30-50 nm, and the material used for the organic active layer is one or more of poly(3-hexylthiophene), pentacene, and tetraacene.
[0010] Preferably, the substrate is selected from silicon wafers, PET plastic or glass, the gate electrode is made of silicon, gold, aluminum, copper or silver, and the source and drain electrodes are made of gold, aluminum, copper or silver.
[0011] A second aspect of the present invention provides a method for fabricating an organic field-effect transistor, the method comprising the following steps:
[0012] Prepare upconversion quantum dot solutions and organic active solutions;
[0013] The upconversion quantum dot solution is coated onto the substrate surface, followed by a first annealing process to form a quantum dot layer.
[0014] The organic active solution is coated onto the surface of the quantum dot layer, followed by a second annealing process to form an organic active layer.
[0015] Source and drain electrodes are deposited on the surface of the organic active layer by vapor deposition;
[0016] The gate electrode is led out using a conductive copper strip at the bottom of the substrate.
[0017] Preferably, the concentration of upconversion quantum dots in the upconversion quantum dot solution is 0.2-0.6 mg / mL; and the concentration of organic active substances in the organic active solution is 2-10 mg / mL.
[0018] Preferably, the step of coating the upconversion quantum dot solution on the substrate surface and performing a first annealing to form a quantum dot layer specifically involves: spin-coating the upconversion quantum dot solution on the substrate surface at a spin-coating speed of 2000-2500 r / min for 20-30 s, and then annealing it at a temperature of 70-150°C for 15-60 min to form a quantum dot layer.
[0019] Preferably, the step of coating the surface of the quantum dot layer with the organic active solution and performing a second annealing to form an organic active layer specifically involves: spin-coating the organic active solution onto the surface of the quantum dot layer at a spin-coating speed of 2000-2500 r / min for 20-30 s, and then annealing it at a temperature of 70-150℃ for 15-60 min to form an organic active layer.
[0020] Preferably, the step of depositing source and drain electrodes on the surface of the organic active layer specifically involves: attaching a mask etched with source and drain electrodes to the surface of the organic active layer, and then... Vapor deposition source and drain electrodes.
[0021] A third aspect of the present invention provides the application of the organic long-effect transistor in the fields of photoelectric detection, imaging, sensor chips or neuromorphic computing.
[0022] Beneficial Effects: This invention provides an organic field-effect transistor (OFET), its fabrication method, and its applications. The OFET structure, from bottom to top, comprises a substrate, a gate electrode, a quantum dot layer, an organic active layer, and source / drain electrodes. The quantum dot layer is made of upconversion quantum dots. This invention combines near-infrared light-sensitive upconversion quantum dots with an organic active material, simultaneously constructing both an organic active layer and a near-infrared light-sensitive quantum dot layer. This helps to compensate for the lack of near-infrared light response in single-component OFETs (organic active layer only), thereby improving the near-infrared light response performance of OFETs.
[0023] In addition, the organic field-effect transistor designed in this invention can not only simulate common synaptic behaviors (such as excitatory postsynaptic currents, double-pulse facilitation, and pulse number-dependent plasticity) under near-infrared illumination, but also demonstrates potential applications in recognizing animal dynamic trajectories in dark environments. Compared to other monitoring technologies, the combination of a single-component (organic active layer only) organic field-effect transistor and upconversion quantum dots has significant advantages, including near-infrared light response, high computational efficiency, and excellent stability and sensitivity, providing an experimental foundation and design reference for the development of next-generation intelligent dynamic image recognition systems. Attached Figure Description
[0024] Figure 1 These are cross-sectional and top views of the organic field-effect transistor prepared according to an embodiment of the present invention.
[0025] Figure 2 This is an electrical test diagram of the organic field-effect transistor prepared according to an embodiment of the present invention.
[0026] Figure 3 This is a current response diagram of a transistor-like synapse under near-infrared light pulse modulation, based on an embodiment of the present invention. Detailed Implementation
[0027] This invention provides an organic field-effect transistor, its fabrication method, and its applications. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0028] Current organic field-effect transistors suffer from a lack of near-infrared light response and the "memory wall" problem caused by the von Neumann architecture.
[0029] Based on this, embodiments of the present invention provide an organic field-effect transistor, wherein the structure of the organic field-effect transistor, from bottom to top, comprises a substrate, a gate electrode, a quantum dot layer, an organic active layer, and source / drain electrodes;
[0030] The quantum dot layer is made of upconversion quantum dots.
[0031] This invention employs an upconversion quantum dot combined with an organic active material. The upconversion quantum dot enhances the infrared light absorption performance of the organic field-effect transistor (OFET), enabling charge trapping and infrared sensing functions. Furthermore, this OFET avoids data transmission redundancy inherent in von Neumann structures and the shortcomings of single-component (organic active layer only) OFETs in near-infrared light response. Simultaneously, by avoiding the von Neumann structure, this OFET can, to some extent, achieve on-chip direct motion trajectory recognition, which is of great significance for the development of next-generation intelligent dynamic image recognition systems.
[0032] In some embodiments, the thickness of the quantum dot layer is 5-20 nm, and the material used for the quantum dot layer is one or more of NaGdF4:Yb / Er, LaF3:Yb / Ho, and LaF3:Yb / Er.
[0033] In some embodiments, the thickness of the organic active layer is 30-50 nm, and the material used for the organic active layer is one or more of poly(3-hexylthiophene), pentacene, and tetraphenylene.
[0034] Upconversion quantum dots exhibit excellent near-infrared response. Specifically, NaGdF4:Yb / Er can absorb 980nm near-infrared light and excite light around 520nm. The 520nm light corresponds precisely to the maximum absorption peak of the organic active layer P3HT, making the organic field-effect transistor as a whole highly sensitive to near-infrared light.
[0035] Setting the quantum dot layer and the organic active layer within this thickness range yields the best photoelectric response characteristics.
[0036] In some embodiments, the substrate is selected from silicon wafers, PET plastic, or glass, the gate electrode is made of silicon, gold, aluminum, copper, or silver, and the source / drain electrodes are made of gold, aluminum, copper, or silver.
[0037] This invention provides a method for fabricating an organic field-effect transistor, the method comprising the following steps:
[0038] Prepare upconversion quantum dot solutions and organic active solutions;
[0039] The upconversion quantum dot solution is coated onto the substrate surface, followed by a first annealing process to form a quantum dot layer.
[0040] The organic active solution is coated onto the surface of the quantum dot layer, followed by a second annealing process to form an organic active layer.
[0041] Source and drain electrodes are deposited on the surface of the organic active layer by vapor deposition;
[0042] The gate electrode is led out using a conductive copper strip at the bottom of the substrate.
[0043] In some embodiments, the concentration of upconversion quantum dots in the upconversion quantum dot solution is 0.2-0.6 mg / mL; and the concentration of organic active substances in the organic active solution is 2-10 mg / mL.
[0044] Setting the concentration of upconversion quantum dots within this range results in optimal uniformity and photoelectric response characteristics for organic field-effect transistors. Too low a concentration of upconversion quantum dots leads to insensitive photoresponse, while too high a concentration leads to poor uniformity of the active layer film and decreased electrical performance.
[0045] In some preferred embodiments, the concentration of upconversion quantum dots in the upconversion quantum dot solution is 0.6 mg / mL; and the concentration of organic active substances in the organic active solution is 6 mg / mL.
[0046] In some embodiments, the solvent in the upconversion quantum dot solution is selected from toluene or chlorobenzene, and the solvent in the organic active solution is selected from chlorobenzene, toluene, or chloroform.
[0047] In some embodiments, the step of coating the upconversion quantum dot solution on the substrate surface and performing a first annealing to form a quantum dot layer specifically involves: spin-coating the upconversion quantum dot solution on the substrate surface at a spin-coating speed of 2000-2500 r / min for 20-30 s, and then annealing it at a temperature of 70-150°C for 15-60 min to form a quantum dot layer.
[0048] In some preferred embodiments, the step of coating the upconversion quantum dot solution on the substrate surface and performing a first annealing to form a quantum dot layer specifically involves: spin-coating the upconversion quantum dot solution on the substrate surface at a spin-coating speed of 2500 r / min for 30 s, and then annealing it at a temperature of 100°C for 40 min to form a quantum dot layer.
[0049] In some embodiments, the step of coating the surface of the quantum dot layer with the organic active solution and performing a second annealing to form an organic active layer specifically involves: spin-coating the organic active solution onto the surface of the quantum dot layer at a spin-coating speed of 2000-2500 r / min for 20-30 s, and then annealing it at a temperature of 70-150°C for 15-60 min to form an organic active layer.
[0050] In some preferred embodiments, the step of spin-coating the organic active solution onto the surface of the quantum dot layer and performing a second annealing to form an organic active layer specifically involves: spin-coating the organic active solution onto the surface of the quantum dot layer at a spin-coating speed of 2500 r / min for 30 s, and then annealing it at a temperature of 100°C for 40 min to form an organic active layer.
[0051] In some embodiments, the step of depositing source and drain electrodes on the surface of the organic active layer specifically involves: attaching a mask etched with source and drain electrodes to the surface of the organic active layer, and then... Vapor deposition source and drain electrodes.
[0052] In some preferred embodiments, 50 nm source and drain electrodes are deposited by vapor deposition.
[0053] In some embodiments, the method for fabricating the organic field-effect transistor includes the following steps:
[0054] Upconversion quantum dots NaGdF4:Yb / Er were dissolved in toluene to prepare an upconversion quantum dot solution with a concentration of 0.6 mg / mL. Poly(3-hexylthiophene) was dissolved in chlorobenzene to prepare an organic active solution with a concentration of 6 mg / mL.
[0055] A quantum dot solution was spin-coated onto the substrate surface at a speed of 2500 r / min for 30 s, and then annealed at 100 °C for 40 min to form a quantum dot layer with a thickness of 40 nm.
[0056] An organic active solution was spin-coated onto the surface of the quantum dot layer at a speed of 2500 r / min for 30 s, and then annealed at 100 °C for 40 min to form an organic active layer with a thickness of 40 nm.
[0057] A mask with source and drain electrode patterns is attached to the surface of the organic active layer, and then, in a state of isolation from air, a photomask is used to... 50nm gold was deposited at a evaporation rate;
[0058] A 1.5cm copper conductive tape is attached to the bottom of the substrate to bring out the gate electrode.
[0059] This invention also provides the application of the organic long-effect transistor in the fields of photoelectric detection, imaging, sensor chips, or neuromorphic computing.
[0060] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are merely some embodiments of the present invention, not all embodiments, and are intended only to illustrate the present invention and not to limit it. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0061] Example
[0062] The fabrication of organic field-effect transistors includes the following steps:
[0063] Preparation of the quantum dot layer and organic active layer: A 100nm oxide silicon wafer was used as the substrate. The wafer was cut into 2cm×2cm cubes. 3mg of upconversion quantum dots NaGdF4:Yb / Er was poured into 5mL of toluene and mechanically stirred for 10 minutes to uniformly disperse the upconversion quantum dots in the toluene, resulting in a 0.6mg / mL upconversion quantum dot solution. The upconversion quantum dot solution was then spin-coated onto the silicon wafer at 2500r / min for 30s, followed by annealing at 100℃ under a nitrogen atmosphere for 40 minutes, yielding a 40nm thick quantum dot layer. 6mg of poly-3-hexylthiophene was poured into 1mL of chlorobenzene and ultrasonically vibrated for 15 minutes to uniformly disperse the poly-3-hexylthiophene in the chlorobenzene, resulting in a 6mg / mL poly-3-hexylthiophene solution. Subsequently, a poly(3-hexylthiophene) solution was spin-coated onto the quantum dot layer at a speed of 2500 r / min for 30 s. The layer was then annealed under a nitrogen atmosphere at 100 °C for 40 minutes, resulting in an organic active layer with a thickness of 40 nm.
[0064] Electrode fabrication: A photomask etched with source and drain electrode patterns is attached to the organic active layer using high-temperature conductive tape. Gold was deposited at a specific rate, with the gold thickness controlled at 50 nm. After deposition, a 1.5 cm long copper conductive tape was attached to the bottom of the silicon wafer to bring out the gate electrode, completing the organic field-effect transistor. The cross-section and top view of the fabricated organic field-effect transistor are shown below. Figure 1 As shown.
[0065] Comparative Example
[0066] The fabrication of organic field-effect transistors includes the following steps:
[0067] Preparation of the organic active layer: A 100nm oxide silicon wafer was used as the substrate, and the wafer was cut into 2cm × 2cm cubes. 6mg of poly-3-hexylthiophene was poured into 1mL of chlorobenzene and ultrasonically vibrated for 15 minutes to uniformly disperse the poly-3-hexylthiophene in the chlorobenzene, obtaining a 6mg / mL poly-3-hexylthiophene solution. The poly-3-hexylthiophene solution was then spin-coated onto the silicon wafer at 2500r / min for 30s. The wafer was then annealed under a nitrogen atmosphere at 100℃ for 40 minutes, resulting in an organic active layer with a thickness of 40nm.
[0068] Electrode fabrication: A photomask etched with source and drain electrode patterns is attached to the organic active layer using high-temperature conductive tape. Gold was deposited at a specific rate, with the gold thickness controlled at 50 nm. After the deposition was completed, a 1.5 cm long copper conductive tape was attached to the bottom of the silicon wafer to bring out the gate electrode, thus completing the organic field-effect transistor.
[0069] Performance testing experiment
[0070] Compared to the comparative example, the photoelectric response performance of the embodiment is improved. The light-induced postsynaptic current change in the embodiment is about 5.5 nA, while the light-induced postsynaptic current change in the comparative example is almost negligible.
[0071] Specifically, the performance of the organic field-effect transistor prepared in this embodiment was tested using a Keysight B2902A digital source meter, a commercial near-infrared light source (980nm), and an optical power meter (Thorlabs).
[0072] The electrical performance test results of the organic field-effect transistor prepared in this embodiment are as follows: Figure 2 As can be seen from the figure, the organic long-effect transistor prepared in this embodiment has a good on / off ratio over a wide voltage range.
[0073] The photoelectric test results of the organic field-effect transistor prepared in this embodiment are as follows: Figure 3 As can be seen from the figure, the organic long-effect transistor prepared in this embodiment exhibits a synaptic-like current response under near-infrared light pulse modulation.
[0074] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. An organic field-effect transistor, characterized in that, The organic field-effect transistor has a structure from bottom to top consisting of a substrate, a gate electrode, a quantum dot layer, an organic active layer, and source / drain electrodes. The quantum dot layer is made of upconversion quantum dots. The thickness of the quantum dot layer is 5-20 nm, and the material used for the quantum dot layer is one or more of NaGdF4:Yb / Er, LaF3:Yb / Ho, and LaF3:Yb / Er. The thickness of the organic active layer is 30-50 nm, and the material used for the organic active layer is one or more of poly(3-hexylthiophene), pentacene, and tetraacene.
2. The organic field-effect transistor according to claim 1, characterized in that, The substrate is selected from silicon wafers, PET plastic, or glass; the gate electrode is made of silicon, gold, aluminum, copper, or silver; and the source and drain electrodes are made of gold, aluminum, copper, or silver.
3. A method for fabricating an organic field-effect transistor as described in claim 1, characterized in that, The preparation method includes the following steps: Prepare upconversion quantum dot solutions and organic active solutions; The upconversion quantum dot solution is coated onto the substrate surface, followed by a first annealing process to form a quantum dot layer. The organic active solution is coated onto the surface of the quantum dot layer, followed by a second annealing process to form an organic active layer. Source and drain electrodes are deposited on the surface of the organic active layer by vapor deposition; The gate electrode is led out using a conductive copper strip at the bottom of the substrate.
4. The method for fabricating an organic field-effect transistor according to claim 3, characterized in that, The concentration of upconversion quantum dots in the upconversion quantum dot solution is 0.2-0.6 mg / mL; The concentration of the organic active substance in the organic active solution is 2-10 mg / mL.
5. The method for fabricating an organic field-effect transistor according to claim 3, characterized in that, The step of coating the upconversion quantum dot solution on the substrate surface and performing a first annealing to form a quantum dot layer is as follows: spin coating the upconversion quantum dot solution on the substrate surface at a spin coating speed of 2000-2500 r / min for 20-30s, and then annealing at a temperature of 70-150℃ for 15-60min to form a quantum dot layer.
6. The method for fabricating an organic field-effect transistor according to claim 3, characterized in that, The step of coating the surface of the quantum dot layer with the organic active solution and performing a second annealing to form an organic active layer is as follows: spin coating the surface of the quantum dot layer with the organic active solution at a spin coating speed of 2000-2500 r / min for 20-30s, and then annealing at a temperature of 70-150℃ for 15-60min to form an organic active layer.
7. The method for fabricating an organic field-effect transistor according to claim 3, characterized in that, The step of vapor-depositing source and drain electrodes on the surface of the organic active layer specifically involves attaching a mask with source and drain electrodes etched on the surface of the organic active layer, and then vapor-depositing the source and drain electrodes.
8. The application of the organic field-effect transistor as described in claim 1 in the fields of photoelectric detection, imaging, sensor chips, or neuromorphic computing.