An organic optoelectronic synapse transistor device based on circularly polarized light response, polymer, preparation method and application

Abstract

The application belongs to the technical field of new materials, and discloses an organic optoelectric synapse transistor device based on circularly polarized light response, a polymer, a preparation method and application. The organic optoelectric synapse transistor device comprises a gate electrode, a gate insulating layer, an active layer and a source-drain electrode which are sequentially connected and arranged from bottom to top. The active layer and the source-drain electrode are sequentially spin-coated or evaporated on the gate electrode with the gate insulating layer from bottom to top, so that the organic device with the functions of circularly polarized light detection and synapse is obtained. The prepared active layer has a large difference between the right-handed circularly polarized light response and the left-handed circularly polarized light response. The highly asymmetric light response enables the device to directly identify the rotational direction information of the circularly polarized light, and provides a core optical basis for the neural morphological calculation of the circularly polarized light coding.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, and in particular to an organic photoelectric synaptic transistor device, polymer, preparation method and application based on circularly polarized light response. Background Technology

[0002] The cross-fertilization of neuromorphic electronics and chiral optics has driven the rapid development of organic circularly polarized synaptic devices. These devices combine circularly polarized light recognition capabilities with synaptic plasticity, showing broad application prospects in cutting-edge fields such as bio-inspired visual systems, quantum encryption, and autonomous navigation. As one of the core performance indicators of these devices, the asymmetry factor (g)... ph The g-value directly quantifies the photoelectric conversion efficiency that distinguishes between left-handed and right-handed circularly polarized light. High g-value devices are a key prerequisite for realizing high-precision circularly polarized light sensing and signal processing.

[0003] Currently, the core challenge in constructing high-performance organic circularly polarized synaptic devices lies in how to synergistically achieve excellent circularly polarized light resolution and efficient charge transport characteristics. Existing research indicates that chiral organic semiconductor materials are the core carriers for constructing the active layer of such devices, and the chiral structure and stacking mode of their molecules directly determine the circularly polarized light response performance of the device. However, traditional chiral organic material preparation strategies often face many limitations: on the one hand, intrinsic chiral materials suffer from complex synthesis steps and difficulty in precisely controlling chiral purity; on the other hand, intriguing chiral induction methods often lead to insufficient material crystallinity and disordered molecular stacking, which in turn causes a decrease in carrier mobility, ultimately limiting the device's performance. ph To improve the value and optimize photoelectric conversion efficiency, the g-factor of existing single active chiral semiconductor layer devices is usually less than 0.5, which is difficult to meet the needs of practical applications.

[0004] Chiral template-induced strategies provide an effective approach for the precise construction of high-performance chiral polymer materials. This method, by introducing chiral templates to regulate the stereochemical structure of polymers, can achieve precise control of the circular dichroism signal of the materials and even significantly enhance the absorption asymmetry factor (g). abs This process also helps improve the crystallinity and molecular order of the material, providing a possibility for balancing chiral optical response and charge transport performance. Using polymer materials prepared by this type of chiral template as the active layer of transistor devices is a reasonable technical approach for constructing high-performance organic circularly polarized optical synaptic devices.

[0005] Despite the significant advantages of chiral template-induced strategies, the application of chiral polymer materials prepared based on these strategies in organic circularly polarized optical synaptic devices remains in the exploratory stage. Existing research largely focuses on the fabrication of devices using single types of chiral materials, and generally suffers from low g-values ​​and limited synaptic plasticity modulation ranges, making it difficult to meet the application requirements of complex scenarios. Therefore, it is crucial to develop diverse chiral template-induced polymer materials and systematically explore their role as active layers in the g-value development of organic circularly polarized optical synaptic devices. ph The regulation of the value and overall performance has become a key technological direction that urgently needs to be broken through in this field, which is of great significance to promoting the practical application of organic circularly polarized optical synaptic devices. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an organic photoelectric synaptic transistor device, polymer, preparation method and application based on circularly polarized light response.

[0007] The technical solution adopted by this invention to solve its technical problem is: A polymer for use in organic photoelectric synaptic transistor devices based on circularly polarized light response, wherein the polymer is a polymer material capable of generating strong circular dichroism through chiral template induction.

[0008] Furthermore, the polymer was synthesized via Stille cross-coupling polymerization, resulting in the design and synthesis of three donor-acceptor type conjugated polymers: 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']dithiophene-thiophene-2-yl)-7-(5-methylthiophene-benzo[c][1,2,5]thiadiazole, i.e., PCPDTTBTT, 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']di ...(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4- The specific molecular structures of the three donor-acceptor conjugated polymers are as follows: (3,2-b:4,5-b')dithiophene-2-yl)-5,6-difluoro-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole (PCPDTTBTT-2F), 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-siloxane-thieno[3,2-b:4,5-b']dithiophene-2-yl)thiophene-2-yl)-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole (PCPDTTBTT-Si-2F). The differentiated molecular structures of the three donor-acceptor conjugated polymers are designed as follows: 1) Regulation of the donor unit Carbon-centered benzodithiophene (C-BDT): The donors of the first two polymers are alkyl-substituted C-BDT derivatives with a central benzene ring and a bisthiophene skeleton, and long alkyl chains are introduced around the periphery to improve solubility and processability.

[0009] Silicon-centered benzodithiophene (Si-BDT): The third polymer replaces the carbon at the center of C-BDT with silicon, changing the electron cloud distribution, rigidity and steric hindrance of the conjugated backbone, and further optimizing intermolecular interactions and chiral assembly capabilities.

[0010] 2) Regulation of receptor units Fluorine-free benzothiadiazole (BT): The first polymer acceptor is a benzo[c][1,2,5]thiadiazole (BT) derivative, which is linked to a bisthiophene unit to construct the basic conjugated structure.

[0011] Fluorinated benzothiadiazole (F-BT): The latter two polymers introduce difluorine atoms to the acceptor, which enhances the intramolecular charge transfer effect, lowers the LUMO energy level to improve electron affinity, and the dipole effect of fluorine atoms can promote orderly intermolecular stacking.

[0012] 3) Polymerization reaction mechanism Using tin-substituted donor monomers and bromine-substituted acceptor monomers as raw materials, Stille coupling occurs under the catalysis of palladium catalyst (tri-o-tolylphosphine) to generate high molecular weight conjugated polymers, ensuring the photoelectric properties and film-forming properties of the material.

[0013] An organic photoelectric synaptic transistor device based on circularly polarized light response is prepared using the polymer described above. The organic photoelectric synaptic transistor device includes a gate, a gate insulating layer, an active layer, and source / drain electrodes connected in sequence. The active layer and source / drain electrodes are spin-coated or vapor-deposited from bottom to top on the gate with the gate insulating layer to obtain an organic device with circularly polarized light detection and synaptic functions.

[0014] Furthermore, the gate is a heavily doped Si substrate; a heavily doped Si wafer is selected as both the gate and the physical substrate, possessing atomically flat characteristics, providing an ideal platform for the uniform deposition of subsequent functional layers. By applying a gate voltage, a vertical electric field can be generated at the interface between the gate insulating layer and the active layer, regulating the hole concentration and distribution within the channel, thereby dynamically changing the conductivity (G) of the active layer. This process directly simulates the "synaptic weight" modulation mechanism of biological synapses.

[0015] Further, the polymer described above is mixed with chiral templates S5011 and R5011 in a 1:1 mass ratio with chloroform solvent and stirred at 45°C for 6 hours on a magnetic stirrer to obtain an active layer mixed solution. Subsequently, the mixed solution is coated onto the surface of the gate insulating layer on the gate using a spin coating process at a speed of 2000 rpm to form a thin film, thus obtaining a substrate. The obtained substrate is then annealed at 250°C for 5 minutes to obtain a gate with a gate insulating layer and an active layer connected together. The chiral templates S5011 and R5011 can induce the polymer chains to form a helical stacked chiral supramolecular structure, generating a strong CD signal, which makes the active layer exhibit significant asymmetric absorption characteristics for left-handed (LCPL) and right-handed (RCPL) circularly polarized light.

[0016] Furthermore, the source and drain electrodes are made of metal Au. Au is a high work function metal, which matches the highest occupied molecular orbital (HOMO) energy level of the p-type conjugated polymer in this invention, enabling the formation of ohmic contacts, significantly reducing the hole injection barrier, and improving carrier injection efficiency. The source electrode is responsible for injecting holes into the channel, while the drain electrode is responsible for collecting carriers, forming a drain-source current, and converting the conductivity change of the active layer into a detectable electrical signal.

[0017] Furthermore, the gate insulating layer is SiO2, which physically isolates the Si gate from the active layer, preventing direct short circuits between the two and ensuring that the electric field only acts on the channel region of the active layer. SiO2 has an extremely high breakdown field strength, which can withstand the instantaneous high electric field of the gate voltage pulse, ensuring the electrical stability of the device; Alternatively, when circularly polarized light is incident on the active layer, the helical symmetry of the chiral superstructure and the rotation direction of the electric field of the circularly polarized light produce a matching effect, triggering selective light absorption and carrier generation: if the chiral superstructure is a left-handed helix, the absorption coefficient for LCPL is much greater than that for RCPL; conversely, the absorption of RCPL is stronger for the right-handed helix structure; this asymmetry comes directly from the CD signal of the chiral superstructure and is the core basis for circularly polarized light identification. Alternatively, the synaptic performance of the polymer PCPDTTBTT-2F-Si device was tested. Under continuous pulse stimulation with left-handed and right-handed circularly polarized light, both polarizations triggered an initial rapid rise in current. Subsequently, under repeated pulse input, it exhibited periodic peak-valley oscillations, reflecting the short-term plasticity of paired pulse facilitation (PPF). Moreover, the current did not completely fall back to the baseline after each pulse, showing the cumulative effect of synaptic weight. The core difference is that the current increase in the RCPL curve is always significantly higher than that in the black LCPL curve, clearly demonstrating the selective response of the device to right-handed circularly polarized light.

[0018] The fabrication method of the organic photoelectric synaptic transistor device described above includes the following steps: The organic circularly polarized photoelectric synapse device includes a gate Si substrate, a gate insulating layer SiO2, an active layer, and a metal Au electrode connected in sequence from bottom to top, thus obtaining an organic synapse device with the function of recognizing circularly polarized light. (1) The gate Si substrate with gate insulating layer SiO2 was ultrasonically cleaned sequentially for 15 minutes with soapy water, deionized water, acetone and ethanol to remove surface impurities. (2) Dry the surface liquid with a nitrogen gun and use plasma cleaning for 40 seconds to further clean the surface and enhance the material’s affinity for the liquid; (3) Dynamically spin-coat the active layer on the gate insulating layer SiO2 at a rotation speed of 1500 to 2000 rpm; (4) Patterned metal Au electrodes are prepared by vacuum evaporation. The channel between the source and drain is the effective area of ​​the device. Finally, a device with circular polarization light detection and synaptic function is formed, and an organic photoelectric synaptic transistor device is obtained.

[0019] Furthermore, the thickness of the gate Si substrate is 600 micrometers, the thickness of the gate insulating layer SiO2 is 300 nanometers, the thickness of the active layer film is 300-400 nanometers, and the thickness of the metal Au electrode is 100 nanometers.

[0020] The above active layer material is used in the fabrication of circularly polarized photoelectric synaptic transistor devices.

[0021] The advantages and positive effects of this invention are as follows: 1. The active layer prepared in this invention has a significantly different responsivity to right-handed circularly polarized light compared to left-handed circularly polarized light. This highly asymmetrical photoresponse allows the device to directly identify the rotation direction information of circularly polarized light, providing a core optical foundation for neuromorphic computation encoded by circularly polarized light.

[0022] 2. This invention constructs a material system with a clear performance gradient by regulating the transformation from carbon-centered benzodithiophene (C-BDT) to silicon-centered benzodithiophene (Si-BDT) and designing acceptors with fluorine-free / difluorinated substituted benzothiadiazoles (BT / F-BT). Among them, the Si-BDT / F-BT polymer forms the most stable chiral superstructure due to the synergy between the rigid framework and the dipole interaction, providing a clear molecular design path for subsequent device performance optimization.

[0023] 3. The device of this invention can simulate various biological synaptic behaviors such as excitatory postsynaptic current (EPSC), paired pulse facilitation (PPF), and the transition from short-term plasticity (STP) to long-term plasticity (LTP), breaking through the limitation of traditional photoelectric synapses lacking polarization selectivity.

[0024] 4. This invention designs and synthesizes three polymer materials that can generate strong circular dichroism through chiral templates, thereby preparing circularly polarized photoelectric synaptic transistor devices, providing a technical solution for high-performance organic semiconductor circularly polarized photoelectric synaptic devices and their preparation methods. Attached Figure Description

[0025] Figure 1 This is a device structure diagram of the organic circularly polarized photoelectric synapse device in Embodiment 4 of the present invention; Figure 2 The figures are current-voltage curves of devices with different polymers as active layers in Example 4 of the present invention; from left to right, they are devices prepared with PCPDTTBTT as active layer; devices prepared with PCPDTTBTT-2F as active layer; and devices prepared with PCPDTTBTT-2F-Si as active layer. Figure 3 The diagram shows the current-time curves of multiple pulses applied to different circularly polarized light in Embodiment 5 of the present invention; the left diagram shows the device fabricated with PCPDTTBTT-2F as the active layer, and the right diagram shows the device fabricated with PCPDTTBTT-2F-Si as the active layer. Detailed Implementation

[0026] The present invention will be further described below with reference to the embodiments. The embodiments described below are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0027] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0028] A polymer for use in organic photoelectric synaptic transistor devices based on circularly polarized light response, wherein the polymer is a polymer material capable of generating strong circular dichroism through chiral template induction.

[0029] Furthermore, the polymer was synthesized via Stille cross-coupling polymerization, resulting in the design and synthesis of three donor-acceptor type conjugated polymers: 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']dithiophene-thiophene-2-yl)-7-(5-methylthiophene-benzo[c][1,2,5]thiadiazole, i.e., PCPDTTBTT, 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']di ...(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4- The specific molecular structures of the three donor-acceptor conjugated polymers are as follows: (3,2-b:4,5-b')dithiophene-2-yl)-5,6-difluoro-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole (PCPDTTBTT-2F), 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-siloxane-thieno[3,2-b:4,5-b']dithiophene-2-yl)thiophene-2-yl)-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole (PCPDTTBTT-Si-2F). The differentiated molecular structures of the three donor-acceptor conjugated polymers are designed as follows: 1) Regulation of the donor unit Carbon-centered benzodithiophene (C-BDT): The donors of the first two polymers are alkyl-substituted C-BDT derivatives with a central benzene ring and a bisthiophene skeleton, and long alkyl chains are introduced around the periphery to improve solubility and processability.

[0030] Silicon-centered benzodithiophene (Si-BDT): The third polymer replaces the carbon at the center of C-BDT with silicon, changing the electron cloud distribution, rigidity and steric hindrance of the conjugated backbone, and further optimizing intermolecular interactions and chiral assembly capabilities.

[0031] 2) Regulation of receptor units Fluorine-free benzothiadiazole (BT): The first polymer acceptor is a benzo[c][1,2,5]thiadiazole (BT) derivative, which is linked to a bisthiophene unit to construct the basic conjugated structure.

[0032] Fluorinated benzothiadiazole (F-BT): The latter two polymers introduce difluorine atoms to the acceptor, which enhances the intramolecular charge transfer effect, lowers the LUMO energy level to improve electron affinity, and the dipole effect of fluorine atoms can promote orderly intermolecular stacking.

[0033] 3) Polymerization reaction mechanism Using tin-substituted donor monomers and bromine-substituted acceptor monomers as raw materials, Stille coupling occurs under the catalysis of palladium catalyst (tri-o-tolylphosphine) to generate high molecular weight conjugated polymers, ensuring the photoelectric properties and film-forming properties of the material.

[0034] An organic photoelectric synaptic transistor device based on circularly polarized light response is prepared using the polymer described above. The organic photoelectric synaptic transistor device includes a gate, a gate insulating layer, an active layer, and source / drain electrodes connected in sequence. The active layer and source / drain electrodes are spin-coated or vapor-deposited from bottom to top on the gate with the gate insulating layer to obtain an organic device with circularly polarized light detection and synaptic functions.

[0035] Furthermore, the gate is a heavily doped Si substrate; a heavily doped Si wafer is selected as both the gate and the physical substrate, possessing atomically flat characteristics, providing an ideal platform for the uniform deposition of subsequent functional layers. By applying a gate voltage, a vertical electric field can be generated at the interface between the gate insulating layer and the active layer, regulating the hole concentration and distribution within the channel, thereby dynamically changing the conductivity (G) of the active layer. This process directly simulates the "synaptic weight" modulation mechanism of biological synapses.

[0036] Further, the polymer described above is mixed with chiral templates S5011 and R5011 in a 1:1 mass ratio with chloroform solvent and stirred at 45°C for 6 hours on a magnetic stirrer to obtain an active layer mixed solution. Subsequently, the mixed solution is coated onto the surface of the gate insulating layer on the gate using a spin coating process at a speed of 2000 rpm to form a thin film, thus obtaining a substrate. The obtained substrate is then annealed at 250°C for 5 minutes to obtain a gate with a gate insulating layer and an active layer connected together. The chiral templates S5011 and R5011 can induce the polymer chains to form a helical stacked chiral supramolecular structure, generating a strong CD signal, which makes the active layer exhibit significant asymmetric absorption characteristics for left-handed (LCPL) and right-handed (RCPL) circularly polarized light.

[0037] Furthermore, the source and drain electrodes are made of metal Au. Au is a high work function metal, which matches the highest occupied molecular orbital (HOMO) energy level of the p-type conjugated polymer in this invention, enabling the formation of ohmic contacts, significantly reducing the hole injection barrier, and improving carrier injection efficiency. The source electrode is responsible for injecting holes into the channel, while the drain electrode is responsible for collecting carriers, forming a drain-source current, and converting the conductivity change of the active layer into a detectable electrical signal.

[0038] Furthermore, the gate insulating layer is SiO2, which physically isolates the Si gate from the active layer, preventing direct short circuits between the two and ensuring that the electric field only acts on the channel region of the active layer. SiO2 has an extremely high breakdown field strength, which can withstand the instantaneous high electric field of the gate voltage pulse, ensuring the electrical stability of the device; Alternatively, when circularly polarized light is incident on the active layer, the helical symmetry of the chiral superstructure and the rotation direction of the electric field of the circularly polarized light produce a matching effect, triggering selective light absorption and carrier generation: if the chiral superstructure is a left-handed helix, the absorption coefficient for LCPL is much greater than that for RCPL; conversely, the absorption of RCPL is stronger for the right-handed helix structure; this asymmetry comes directly from the CD signal of the chiral superstructure and is the core basis for circularly polarized light identification. Alternatively, the synaptic performance of the polymer PCPDTTBTT-2F-Si device was tested. Under continuous pulse stimulation with left-handed and right-handed circularly polarized light, both polarizations triggered an initial rapid rise in current. Subsequently, under repeated pulse input, it exhibited periodic peak-valley oscillations, reflecting the short-term plasticity of paired pulse facilitation (PPF). Moreover, the current did not completely fall back to the baseline after each pulse, showing the cumulative effect of synaptic weight. The core difference is that the current increase in the RCPL curve is always significantly higher than that in the black LCPL curve, clearly demonstrating the selective response of the device to right-handed circularly polarized light.

[0039] The fabrication method of the organic photoelectric synaptic transistor device described above includes the following steps: The organic circularly polarized photoelectric synapse device includes a gate Si substrate, a gate insulating layer SiO2, an active layer, and a metal Au electrode connected in sequence from bottom to top, thus obtaining an organic synapse device with the function of recognizing circularly polarized light. (1) The gate Si substrate with gate insulating layer SiO2 was ultrasonically cleaned sequentially for 15 minutes with soapy water, deionized water, acetone and ethanol to remove surface impurities. (2) Dry the surface liquid with a nitrogen gun and use plasma cleaning for 40 seconds to further clean the surface and enhance the material’s affinity for the liquid; (3) Dynamically spin-coat the active layer on the gate insulating layer SiO2 at a rotation speed of 1500 to 2000 rpm; (4) Patterned metal Au electrodes are prepared by vacuum evaporation. The channel between the source and drain is the effective area of ​​the device. Finally, a device with circular polarization light detection and synaptic function is formed, and an organic photoelectric synaptic transistor device is obtained.

[0040] Furthermore, the thickness of the gate Si substrate is 600 micrometers, the thickness of the gate insulating layer SiO2 is 300 nanometers, the thickness of the active layer film is 300-400 nanometers, and the thickness of the metal Au electrode is 100 nanometers.

[0041] The above active layer material is used in the fabrication of circularly polarized photoelectric synaptic transistor devices.

[0042] Specifically, the relevant preparation and testing methods are as follows: Example 1 A polymer for use in organic photoelectric synaptic transistor devices based on circularly polarized light response, wherein the polymer is a polymer material capable of generating strong circular dichroism induced by a chiral template, and its preparation is as follows: Under nitrogen protection, 0.1 mmol of (4,4-bis(2-ethylhexyl)-4H-cyclopentano[1,2-b:5,4-b']dithiophene-2,6-diyl)bis(trimethylstanane) (CAS No. 920504-00-3), 0.1 mmol of 4,7-bis(2-bromo-5-thienyl)-2,1,3-benzothiadiazole (CAS No. 288071-87-4), the main catalyst tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), and tri-o-tolylphosphine (P(o-Tol)3) were placed in a reaction flask. After adding 2.0 mL of tetrahydrofuran, the mixture was stirred at 100 °C for 24 hours. After adding 20.0 mL of methanol, the resulting precipitate was filtered. The precipitated polymer was subjected to Soxhlet extraction, using acetone, n-hexane, and chloroform as extraction solvents sequentially. The extraction temperature was controlled at 100℃, and the extraction time for each solvent was 12 hours. The filtrate after chloroform extraction was concentrated under reduced pressure at 60℃, followed by the addition of 20.0 mL of methanol to precipitate the polymer. After filtration, the precipitate was dried in a 60℃ oven for 12 hours to complete the sample processing. A black polymeric solid was obtained. The molecular formula of the polymer is as follows: .

[0043] Example 2 A polymer for use in organic photoelectric synaptic transistor devices based on circularly polarized light response, wherein the polymer is a polymer material capable of generating strong circular dichroism induced by a chiral template, and its preparation is as follows: Under nitrogen protection, 0.1 mmol of (4,4-bis(2-ethylhexyl)-4H-cyclopentano[1,2-b:5,4-b']dithiophene-2,6-diyl)bis(trimethylstanane) (CAS No. 920504-00-3), 0.1 mmol of 4,7-bis(5-bromothiophene-2-yl)-5,6-difluorobenzo[c][1,2,5]thiadiazole (CAS No. 1304773-89-4), the main catalyst tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), and tri-o-tolylphosphine (P(o-Tol)3) were placed in a reaction flask. After adding 2.0 mL of tetrahydrofuran, the mixture was stirred at 100 °C for 24 hours. After adding 20.0 mL of methanol, the resulting precipitate was filtered. The precipitated polymer was subjected to Soxhlet extraction, using acetone, n-hexane, and chloroform as extraction solvents sequentially. The extraction temperature was controlled at 100℃, and the extraction time for each solvent was 12 hours. The filtrate after chloroform extraction was concentrated under reduced pressure at 60℃, followed by the addition of 20.0 mL of methanol to precipitate the polymer. After filtration, the precipitate was dried in a 60℃ oven for 12 hours to complete the sample processing. A black polymeric solid was obtained. The molecular formula of the polymer is as follows: .

[0044] Example 3 A polymer for use in organic photoelectric synaptic transistor devices based on circularly polarized light response, wherein the polymer is a polymer material capable of generating strong circular dichroism induced by a chiral template, and its preparation is as follows: Under nitrogen protection, 0.1 mmol of 4,4'-bis(2-ethylhexyl)-5,5'-bis(trimethyltin)-thiophene[3,2-b:2,3-d]silanecyclopentadiene (CAS No. 1089687-06-8), 0.1 mmol of 4,7-bis(5-bromothiophene-2-yl)-5,6-difluorobenzo[c][1,2,5]thiadiazole (CAS No. 1304773-89-4), the main catalyst tris(dibenzylacetone)palladium (Pd2(dba)3), and tri-o-tolylphosphine (P(o-Tol)3) were placed in a reaction flask. After adding 2.0 mL of tetrahydrofuran, the mixture was stirred at 100 °C for 24 hours. After adding 20.0 mL of methanol, the resulting precipitate was filtered. The precipitated polymer was subjected to Soxhlet extraction, using acetone, n-hexane, and chloroform as extraction solvents sequentially. The extraction temperature was controlled at 100℃, and the extraction time for each solvent was 12 hours. The filtrate after chloroform extraction was concentrated under reduced pressure at 60℃, followed by the addition of 20.0 mL of methanol to precipitate the polymer. After filtration, the precipitate was dried in a 60℃ oven for 12 hours to complete the sample processing. A black polymeric solid was obtained. The molecular formula of the polymer is as follows: .

[0045] like Figure 1 As shown, the organic circularly polarized photoelectric synaptic device includes a gate, a gate insulating layer, an active layer, and source / drain electrodes arranged sequentially from bottom to top. The active layer and source / drain electrodes are spin-coated or vapor-deposited sequentially from bottom to top on a heavily doped Si substrate with a gate insulating layer to obtain an organic device with circularly polarized light detection and synaptic functions.

[0046] The heavily doped Si wafer serves as the physical substrate for the entire device. Its atomically flat surface provides an ideal platform for the uniform deposition of subsequent layers. By applying a gate voltage, a vertical electric field is generated at the interface between SiO and the active layer, regulating the hole concentration and distribution within the channel, thereby dynamically altering the conductance (G) of the active layer. This process directly simulates the "synaptic weight" modulation of biological synapses.

[0047] The gate insulating layer is SiO2, which physically isolates the Si gate from the active layer, preventing direct short circuits between the two and ensuring that the electric field only acts on the channel region of the active layer. SiO2 has an extremely high breakdown field strength, which can withstand the instantaneous high electric field of the gate voltage pulse, ensuring the electrical stability of the device.

[0048] The active layer material is one of the three polymers mentioned above: 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']dithiophene-thiophene-2-yl)-7-(5-methylthiophene-benzo[c][1,2,5]thiadiazole (PCPDTTBTT), 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H- Cyclopenta[2,1-b:3,4-b']dithiophene-2-yl)thiophene-2-yl)-5,6-difluoro-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole (PCPDTTBTT-2F), 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-silazenothiophene[3,2-b:4,5-b']dithiophene-2 (-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole (PCPDTTBTT-2F-Si) was mixed with chiral templates (chiral agents) S5011 and R5011 at a mass ratio of 1:1 in chloroform solvent. The mixture was stirred at 45°C for 6 hours on a magnetic stirrer to obtain an active layer mixture solution. Subsequently, the mixture was spin-coated onto the surface of a SiO2 substrate at a speed of 2000 rpm to form a thin film. The resulting substrate was then annealed at 250°C for 5 minutes to induce the chiral templates S5011 and R5011 to form a helical stacked chiral supramolecular structure, generating a strong CD signal, i.e., exhibiting significant asymmetric absorption of left-handed (LCPL) and right-handed (RCPL) circularly polarized light.

[0049] Au electrodes are selected as the source and drain electrodes. Au is a high work function metal that matches the highest occupied molecular orbital energy level of the p-type conjugated polymer of this invention, forming an ohmic contact, which greatly reduces the hole injection barrier and improves the carrier injection efficiency. The source electrode is responsible for injecting holes into the channel, and the drain electrode is responsible for collecting carriers to form a drain-source current, which converts the change in the conductivity of the active layer into a detectable electrical signal.

[0050] When circularly polarized light is incident on the active layer, the helical symmetry of the chiral superstructure and the rotation direction of the electric field of the circularly polarized light produce a matching effect, inducing selective light absorption and carrier generation: if the chiral superstructure is a left-handed helix, the absorption coefficient for LCPL is much greater than that for RCPL; conversely, a right-handed helix structure has a stronger absorption for RCPL. This asymmetry comes directly from the CD signal of the chiral superstructure and is the core basis for circularly polarized light identification.

[0051] Testing the synaptic properties of the polymer PCPDTTBTT-2F-Si device, such as... Figure 3As shown, under continuous pulse stimulation from left-handed and right-handed circularly polarized light, both types of polarization triggered an initial rapid rise in current. Subsequently, under repeated pulse input, periodic peak-valley oscillations were observed, reflecting the short-term plasticity characteristics of paired pulse facilitation (PPF). Moreover, the current did not completely fall back to the baseline after each pulse, exhibiting the cumulative effect of synaptic weights. The core difference lies in the fact that the current increase in the RCPL curve is always significantly higher than that in the black LCPL curve, clearly demonstrating the selective response of the device to right-handed circularly polarized light.

[0052] The fabrication method of the organic circularly polarized photoelectric synapse device described above includes the following steps: the organic circularly polarized photoelectric synapse device comprises, from bottom to top, a gate Si substrate, a gate insulating layer SiO2, an active layer, and a metal Au electrode, which are sequentially connected together, as shown in the structural diagram below. Figure 1 As shown, an organic synaptic device capable of recognizing circularly polarized light was obtained.

[0053] (1) The gate Si substrate with gate insulating layer SiO2 was ultrasonically cleaned sequentially for 15 minutes with soapy water, deionized water, acetone and ethanol to remove surface impurities. (2) Dry the surface liquid with a nitrogen gun and use plasma cleaning for 40 seconds to further clean the surface and enhance the material’s affinity for the liquid; (3) Dynamically spin-coat the active layer on the gate insulating layer SiO2 at a rotation speed of 1500 to 2000 rpm; (4) Patterned metal Au electrodes are prepared by vacuum evaporation. The channel between the source and drain is the effective area of ​​the device, and finally a device with circular polarization light detection and synaptic function is formed.

[0054] Furthermore, the thickness of the gate Si substrate is 600 micrometers, the thickness of the gate insulating layer SiO2 is 300 nanometers, the thickness of the active layer film is 300-400 nanometers, and the thickness of the metal Au electrode is 100 nanometers.

[0055] Example 4 Three polymer materials were used to prepare chiral thin films as the active layer of transistor devices. I / V curves were then tested. Figure 2 The device performance is shown in the figure: thin film g prepared from polymer PCPDTTBTT ph =0.75, responsivity R=0.004 A / W, external quantum efficiency EQE=0.75%, specific detectivity D Thin film g prepared by polymer PCPDTTBTT-2F ph =1.03, responsivity R=0.073 A / W, external quantum efficiency EQE=13.8%, specific detectivity D Thin films g prepared from polymer PCPDTTBTT-2F-Siph =1.17, responsivity R=1.15 A / W, external quantum efficiency EQE=216%, specific detectivity D The core optoelectronic performance parameters of the device were obtained through test curves. The various indicators exhibited a significant step-like leap from PCPDTTBTT to PCPDTTBTT-2F and then to PCPDTTBTT-2F-Si, with the photoresponse asymmetry factor g... ph The invention achieves a continuous increase in g-value, breaking through the bottleneck of existing technologies and qualitatively improving the resolution of circularly polarized light. It significantly enhances the asymmetric absorption characteristics of circularly polarized light, enabling a qualitative breakthrough in the accuracy of circularly polarized light rotation identification. This lays a core foundation for high-precision circularly polarized light sensing and signal processing. The responsivity R increases exponentially, photoelectric conversion efficiency is greatly optimized, and the photoelectric signal conversion capability is significantly enhanced, enabling more efficient conversion of circularly polarized light signals into detectable electrical signals. The external quantum efficiency (EQE) exceeds 100% and achieves a significant improvement, exhibiting a carrier multiplication effect. This represents a breakthrough leap in photoelectric conversion performance, giving the device both selective and strong absorption characteristics of circularly polarized light and efficient charge transport and separation capabilities. This optimizes the generation, transport, and collection efficiency of photogenerated carriers within the device, far exceeding that of devices prepared from traditional chiral polymer materials, fully demonstrating the advanced molecular design of this invention.

[0056] Example 5 To test the synaptic properties of devices fabricated from the polymer PCPDTTBTT-2F-Si, continuous pulses of left-handed and right-handed circularly polarized light were used for stimulation. Figure 3As shown, under both types of polarized light stimulation, the current initially rises rapidly and then exhibits periodic peak-valley oscillations under subsequent repetitive pulses, demonstrating the short-term plasticity characteristic of paired pulse facilitation (PPF). Furthermore, the current does not fully recover to the baseline level after each pulse, indicating the cumulative effect of synaptic weighting. Notably, throughout the entire test, the current gain corresponding to right-hand circularly polarized light (RCPL) is consistently significantly higher than that of left-hand circularly polarized light (LCPL), clearly demonstrating the selective response characteristics of this device to right-hand circularly polarized light. The left figure shows the synaptic current response curves of the PCPDTTBTT-2F device, with a current variation range of ΔI≈0-2nA. The peak current induced by right-hand circularly polarized light is approximately 1.7–1.0nA, while the peak current induced by left-hand circularly polarized light (LCP) is approximately 1.2–1.4nA. The response amplitude of RCP is about 30%–40% higher than that of LCP, and the initial current growth rate of RCP is faster, indicating that the carrier generation efficiency induced by right-hand circularly polarized light is higher. The right figure shows the synaptic current response curves in the high response amplitude range, with a current variation range of ΔI≈0–4nA. The peak current induced by RCP is approximately 3.8–4nA, while the peak current induced by LCP is approximately 2.5–2.8nA. The response amplitude of RCP is about 50%–60% higher than that of LCP, and the peak-valley oscillation difference of the curve is more obvious, indicating a more significant synaptic facilitation effect. Therefore, the device fabricated with PCPDTTBTT-2F-Si has more accurate recognition of circularly polarized light. Furthermore, the current did not completely fall back to the baseline after each pulse, but remained at a high level, reflecting the cumulative nature of synaptic weights and simulating the trend of biological synapses transitioning from "short-term memory" to "long-term memory".

[0057] In summary, the technical solutions provided by the embodiments of the present invention have designed and synthesized three polymer materials that can be induced to exhibit strong circular dichroism using chiral templates, and fabricated circularly polarized photoelectric synaptic transistor devices, providing high-performance organic semiconductor circularly polarized photoelectric synaptic devices. The technical solutions of the present invention have a simple structure and do not require complex fabrication processes, thus possessing broad development potential in the field of intelligent optoelectronic sensing.

[0058] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A polymer for use in organic photoelectric synaptic transistor devices based on circularly polarized light response, characterized in that: The polymer is a polymer material that can generate strong circular dichroism through chiral template induction.

2. The polymer according to claim 1, characterized in that: The polymers were synthesized via Stille cross-coupling polymerization. Three donor-acceptor type conjugated polymers were designed and synthesized, specifically 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']dithiophene-thiophene-2-yl)-7-(5-methylthiophene-benzo[c][1,2,5]thiadiazole, i.e., PCPDTTBTT, and 4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-cyclopentano[2,1-b:3,4-b']dithiophene-2-yl) The specific molecular structures of the three donor-acceptor conjugated polymers, namely PCPDTTBTT-2F (thiophene-2-yl)-5,6-difluoro-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole and PCPDTTBTT-Si-2F (4-(5-(4,4-bis(2-ethylhexyl)-6-methyl-4H-siloxane-thiophene[3,2-b:4,5-b']dithiophene-2-yl)thiophene-2-yl)-7-(5-methylthiophene-2-yl)benzo[c][1,2,5]thiadiazole, are as follows: 。 3. An organic photoelectric synaptic transistor device based on circularly polarized light response, prepared using the polymer as described in claim 1 or 2, characterized in that: The organic photoelectric synaptic transistor device includes a gate, a gate insulating layer, an active layer, and source / drain electrodes connected in sequence. The active layer and source / drain electrodes are spin-coated or vapor-deposited from bottom to top on the gate with the gate insulating layer to obtain an organic device with circularly polarized light detection and synaptic functions.

4. The organic photoelectric synaptic transistor device according to claim 3, characterized in that: The gate is a heavily doped Si substrate.

5. The organic photoelectric synaptic transistor device according to claim 3, characterized in that: The polymer as described in claim 1 or 2 is mixed with chiral templates S5011 and R5011 in a mass ratio of 1:1 in chloroform solvent and stirred at 45°C for 6 hours on a magnetic stirring table to obtain an active layer mixed solution. Subsequently, the mixed solution is coated onto the surface of the gate insulating layer on the gate at a rotation speed of 2000 rpm to form a thin film, thus obtaining a substrate. The obtained substrate was annealed at 250°C for 5 minutes to obtain a gate with a gate insulating layer and an active layer connected together. The chiral templates S5011 and R5011 can induce the polymer chains to form a chiral supramolecular structure with helical stacking, generating a strong CD signal, so that the active layer exhibits significant asymmetric absorption characteristics for left-handed (LCPL) and right-handed (RCPL) circularly polarized light.

6. The organic photoelectric synaptic transistor device according to claim 3, characterized in that: The source and drain electrodes are made of metal Au.

7. The organic photosynthetic transistor device according to any one of claims 3 to 6, characterized in that: The gate insulating layer is SiO2; Alternatively, when circularly polarized light is incident on the active layer, the helical symmetry of the chiral superstructure and the rotation direction of the electric field of the circularly polarized light produce a matching effect, triggering selective light absorption and carrier generation: if the chiral superstructure is a left-handed helix, the absorption coefficient for LCPL is much greater than that for RCPL; conversely, the absorption of RCPL is stronger for the right-handed helix structure; this asymmetry comes directly from the CD signal of the chiral superstructure and is the core basis for circularly polarized light identification. Alternatively, the synaptic performance of the polymer PCPDTTBTT-2F-Si device was tested. Under continuous pulse stimulation with left-handed and right-handed circularly polarized light, both polarizations triggered an initial rapid rise in current. Subsequently, under repeated pulse input, it exhibited periodic "peak-valley" oscillations, reflecting the short-term plasticity characteristics facilitated by paired pulses. Moreover, the current did not completely fall back to the baseline after each pulse, showing the cumulative effect of synaptic weight. The key difference lies in the fact that the current increase in the RCPL curve is always significantly higher than that in the black LCPL curve, clearly demonstrating the device's selective response to right-hand circularly polarized light.

8. The method for fabricating the organic photoelectric synaptic transistor device according to any one of claims 3 to 7, characterized in that: Includes the following steps: The organic circularly polarized photoelectric synapse device includes a gate Si substrate, a gate insulating layer SiO2, an active layer, and a metal Au electrode connected in sequence from bottom to top, thus obtaining an organic synapse device with the function of recognizing circularly polarized light. (1) The gate Si substrate with gate insulating layer SiO2 was ultrasonically cleaned sequentially for 15 minutes with soapy water, deionized water, acetone and ethanol to remove surface impurities. (2) Dry the surface liquid with a nitrogen gun and use plasma cleaning for 40 seconds to further clean the surface and enhance the material’s affinity for the liquid; (3) Dynamically spin-coat the active layer on the gate insulating layer SiO2 at a rotation speed of 1500 to 2000 rpm; (4) Patterned metal Au electrodes are prepared by vacuum evaporation. The channel between the source and drain is the effective area of ​​the device. Finally, a device with circular polarization light detection and synaptic function is formed, and an organic photoelectric synaptic transistor device is obtained.

9. The preparation method according to claim 8, characterized in that: The gate Si substrate has a thickness of 600 micrometers, the gate insulating layer SiO2 has a thickness of 300 nanometers, the active layer has a thickness of 300-400 nanometers, and the metal Au electrode has a thickness of 100 nanometers.

10. The application of the active layer material as described in claim 1 or 2 in the fabrication of circularly polarized photoelectric synaptic transistor devices.

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