Printable synapse transistor based on wide-band-gap oxide and narrow-band-gap quantum dot dual active layer

Abstract

The invention relates to a printable synapse transistor based on a wide band gap oxide and narrow band gap quantum dot double active layer, which is provided with a glass substrate, a dielectric layer, an active layer, a source electrode, a grid electrode and a drain electrode, therefore, the printable synapse transistor operates through the high mobility characteristic of the wide-band-gap oxide, and wide spectral response is generated through the narrow-band-gap characteristic of the narrow-band-gap quantum dots. The dielectric layer is an electret dielectric layer, and the electret dielectric layer regulates and controls the electron concentration of the active layer through polarization. According to the printable synapse transistor, normal operation is carried out through the high mobility characteristic of the wide-band-gap oxide, and wide spectral response is generated through the narrow-band-gap characteristic of the narrow-band-gap quantum dots, so that the printable synapse transistor carries out electric signal regulation and control in the range of more than four orders of magnitude when the source-drain voltage is below 5V and the active layer is in the range of more than four orders of magnitude; and the active layer is regulated and controlled by an ultra-wide spectrum optical signal from ultraviolet to near infrared.

Description

Technical Field

[0001] The present invention relates to the technical field of thin film transistors, and particularly to a printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots. Background Art

[0002] With the rapid development of human-computer interaction and wearable technologies, electronic devices are evolving towards seamless integration with the human body. Wearable systems centered around electronic skin, which can directly adhere to human skin and monitor physiological signals, sense environmental information, and enable intelligent interaction in real time, have become a forefront research direction in the field of flexible electronics. However, oxide thin film transistors (TFTs), which are the core devices of electronic skin, still face dual challenges in terms of material properties and manufacturing processes, severely restricting their practical applications.

[0003] Currently, oxide transistors such as those based on wide bandgap oxide semiconductors like IGZO and ZnO, although showing potential in display driving, sensing, and brain-inspired computing, urgently need to improve their functionality and energy efficiency. The single active layer structure is limited by the single bandgap of the material and is difficult to simultaneously achieve high light responsivity and low power consumption characteristics. For example, wide bandgap oxides, although having high stability and carrier mobility, have a narrow light absorption range, which limits their application in photoelectric sensing. Narrow bandgap semiconductors, such as organic materials, can broaden the spectral response, but have low carrier transport efficiency and poor environmental stability. In addition, traditional dielectric layers (such as SiO2, PI) have a low dielectric constant (k < 5), forcing the device to require a high operating voltage (> 10V), making it difficult to meet the requirements of low voltage operation and low power consumption.

[0004] Therefore, in view of the deficiencies of the prior art, it is highly necessary to provide a printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots to address the deficiencies of the prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots, avoiding the deficiencies of the prior art. This printable synaptic transistor can achieve optical and electrical signal sensing and ultra-wide spectral response.

[0006] The above object of the present invention is achieved by the following technical measures:

[0007] Provide a printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots, which is provided with a glass substrate, a dielectric layer, an active layer, a source electrode, a gate electrode, and a drain electrode.

[0008] Preferably, the above active layer contains a wide-bandgap oxide and narrow-bandgap quantum dots, so that the printable synaptic transistor operates through the high mobility characteristics of the wide-bandgap oxide, and a wide-spectrum response is generated through the narrow-bandgap characteristics of the narrow-bandgap quantum dots;

[0009] Preferably, the above dielectric layer is an electret dielectric layer, and the electret dielectric layer regulates the electron concentration of the active layer through polarization.

[0010] Preferably, the above wide-bandgap oxide forms an oxide semiconductor layer.

[0011] Preferably, the above narrow-bandgap quantum dots form a quantum dot semiconductor layer.

[0012] Preferably, the above oxide semiconductor layer and the quantum dot semiconductor layer are stacked to form a dual-active layer structure, and the oxide semiconductor layer is located on the lower surface of the quantum dot semiconductor layer.

[0013] Preferably, the above wide-bandgap oxide is at least one of In element oxide, Zn element oxide, Ga element oxide, Sn element oxide or Cd element oxide.

[0014] Preferably, the above narrow-bandgap quantum dots contain at least one of Pb element, Cd element, Se element, Te element, Zn element, S element, In element or P element.

[0015] Preferably, the above oxide semiconductor layer is prepared by a printing method.

[0016] Preferably, the above quantum dot semiconductor layer is processed from an inorganic quantum dot solution.

[0017] Preferably, the above electret dielectric layer is processed from a polymer solution.

[0018] The polymer contains at least one of strong polar groups such as amide group, cyano group, amino group or hydroxyl group.

[0019] For the printable synaptic transistor based on the dual-active layer of wide-bandgap oxide and narrow-bandgap quantum dots of the present invention, the preparation sequence from front to back is the gate, the electret dielectric layer, the oxide semiconductor layer, the quantum dot semiconductor layer, and finally the source electrode and the drain electrode are prepared.

[0020] For the printable synaptic transistor based on the dual-active layer of wide-bandgap oxide and narrow-bandgap quantum dots of the present invention, when the source-drain voltage is below 5V, the active layer conducts electrical signal regulation in a range greater than 4 orders of magnitude, and the active layer conducts ultra-wide spectrum optical signal regulation from ultraviolet to near-infrared.

[0021] A printable synaptic transistor based on a double active layer of wide-bandgap oxide and narrow-bandgap quantum dots according to the present invention is provided with a glass substrate, a dielectric layer, an active layer, a source electrode, a gate electrode, and a drain electrode. The active layer contains a wide-bandgap oxide and narrow-bandgap quantum dots, so that the printable synaptic transistor operates through the high mobility characteristics of the wide-bandgap oxide, and a wide spectral response is generated through the narrow bandgap characteristics of the narrow-bandgap quantum dots; the dielectric layer is an electret dielectric layer, and the electret dielectric layer regulates the electron concentration of the active layer through polarization. The printable synaptic transistor of the present invention operates normally through the high mobility characteristics of the wide-bandgap oxide, and a wide spectral response is generated through the narrow bandgap characteristics of the narrow-bandgap quantum dots, so that the printable synaptic transistor can perform electrical signal regulation in the active layer within a range greater than 4 orders of magnitude when the source-drain voltage is below 5V, and ultra-wide spectral optical signal regulation from ultraviolet to near-infrared in the active layer. Brief Description of the Drawings

[0022] The present invention will be further described with reference to the accompanying drawings, but the content in the drawings does not constitute any limitation to the present invention.

[0023] Figure 1 It is a schematic structural diagram of a printable synaptic transistor.

[0024] Figure 2 It is a flowchart for preparing the printable synaptic transistor of Example 2.

[0025] Figure 3 It is a schematic energy band diagram and working mechanism of a printable synaptic transistor, where Figure 3 (a) is the energy band diagram of the wide-bandgap oxide and the narrow-bandgap quantum dots respectively; Figure 3 (b) is the bending situation of the energy band diagram after the wide-bandgap oxide and the narrow-bandgap quantum dots are in contact.

[0026] Figure 4 It is the transfer characteristic curve and output characteristic curve of a printable synaptic transistor. Figure 4 (a) is the transfer characteristic curve of a printable synaptic transistor, and the gate voltage (V G ) scanning range is from -1 to 3V, and the on-off ratio is greater than 10 4 ; Figure 4 (b) is the output curve of a printable synaptic transistor, and the source voltage (V D ) scanning range is from 0 to 1V.

[0027] Figure 5 It is the synaptic performance of a printable synaptic transistor under electrical signal stimulation, where Figure 5 (a) is the PSC curve under different pulse widths, Figure 5 (b) is the paired-pulse facilitation (PPF) curve under two consecutive pulses when the time interval (Δt) is 50ms.

[0028] Figure 6 It is a graph of the post - synaptic current (PSC) of a printable synaptic transistor versus time (t) under ultraviolet light.

[0029] Figure 7 It is a graph of the post - synaptic current (PSC) of a printable synaptic transistor versus time (t) under green light.

[0030] Figure 8 It is a graph of the post - synaptic current (PSC) of a printable synaptic transistor versus time (t) under near - infrared light.

[0031] In Figures 1 to 8 it includes:

[0032] A glass substrate 10, a gate 11, a dielectric layer 12, an active layer 13, a source 14a and a drain 14b. Specific embodiments

[0033] The technical solution of the present invention will be further described in conjunction with the following embodiments. The experimental methods in the following embodiments are all conventional methods unless otherwise specified. The raw materials, reagent materials, etc. used in the following embodiments can be obtained from conventional biochemical reagent stores or drug - operating enterprises unless otherwise specified.

[0034] Embodiment 1

[0035] A printable synaptic transistor based on a dual - active layer of wide - bandgap oxide and narrow - bandgap quantum dots, as Figure 1 shown, is provided with a glass substrate 10, a dielectric layer 12, an active layer 13, a source 14a, a gate 11 and a drain 14b. The active layer 13 is a dual - active layer structure composed of a wide - bandgap oxide and a narrow - bandgap quantum dot. Thus, the printable synaptic transistor operates through the high - mobility characteristics of the wide - bandgap oxide, and a wide - spectrum response is generated through the narrow - bandgap characteristics of the narrow - bandgap quantum dot. The dielectric layer 12 of the present invention is an electret dielectric layer 12, and the electret dielectric layer regulates the electron concentration of the active layer 13 through polarization.

[0036] The printable synaptic crystal of the present invention operates normally through the high - mobility characteristics of the wide - bandgap oxide and generates a wide - spectrum response through the narrow - bandgap characteristics of the narrow - bandgap quantum dot.

[0037] The wide - bandgap oxide constitutes an oxide semiconductor layer (not shown in the figure). The narrow - bandgap quantum dot constitutes a quantum dot semiconductor layer (not shown in the figure). The oxide semiconductor layer and the quantum dot semiconductor layer are stacked to form an active layer, which is a dual - active layer structure, and the oxide semiconductor layer is located on the lower surface of the quantum dot semiconductor layer.

[0038] The wide bandgap oxide is at least one of oxides of In element, Zn element, Ga element, Sn element or Cd element. The narrow bandgap quantum dots contain at least one of Pb element, Cd element, Se element, Te element, Zn element, S element, In element or P element.

[0039] The oxide semiconductor layer is prepared by a printing method; the quantum dot semiconductor layer is processed from an inorganic quantum dot solution.

[0040] The electret dielectric layer is processed from a polymer solution; the polymer film contains at least one of strongly polar groups such as amide group, cyano group, amino group or hydroxyl group.

[0041] The printable synaptic transistor operates normally through the high mobility characteristics of the wide bandgap oxide, and generates a wide spectral response through the narrow bandgap characteristics of the narrow bandgap quantum dots, so that the printable synaptic transistor can perform electrical signal regulation in the active layer within a range greater than 4 orders of magnitude when the source-drain voltage is below 5V, and the active layer can perform ultra-wide spectral optical signal regulation from ultraviolet to near-infrared. By constructing a double active layer structure of wide bandgap oxide and narrow bandgap quantum dots, the printable synaptic transistor synergistically utilizes the high mobility of the oxide semiconductor and the wide spectral absorption characteristics of the quantum dots, and combines energy band engineering design to achieve efficient separation and transport of photo-generated carriers, thereby improving the photoelectric response range and energy efficiency of the device. The printable synaptic transistor of the present invention uses a solution-processable high-k polymer electret as the dielectric layer, which not only realizes low-voltage driving and non-volatile polarization storage, but also can achieve integrated patterning of the gate, source / drain through a printing process, avoiding complex alignment steps and significantly reducing the manufacturing cost.

[0042] Example 2

[0043] A printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots, with other features the same as those in Example 1, except that: the preparation order of the printable synaptic transistor from front to back is gate 11, electret dielectric layer 12, oxide semiconductor layer, quantum dot semiconductor layer, and finally the source electrode 14a and drain electrode 14b are prepared.

[0044] For the printable synaptic transistor of this embodiment, as Figure 1 shown, a part of the source electrode 14a overlaps on the upper surface of the electret dielectric layer 12, and another part of the source electrode 14a overlaps on the upper surface of the active layer 13; a part of the drain electrode 14b overlaps on the upper surface of the electret dielectric layer 12, and a part of the drain electrode 14b overlaps on the upper surface of the active layer 13, and the source electrode 14a and the drain electrode 14b are not connected to each other.

[0045] As Figure 2As shown, the preparation process of the printable synaptic transistor in this example includes the following steps:

[0046] S1. Clean the glass substrate 10 and deposit a 150-nm gate 11 film.

[0047] S2. Prepare the electret dielectric layer 12 by printing.

[0048] S3. Anneal and cure the electret dielectric layer 12 prepared in S2 in air.

[0049] S4. Prepare the oxide semiconductor layer by printing on the electret dielectric layer 12 prepared in S3.

[0050] S5. Anneal the oxide semiconductor layer prepared in S4 in air.

[0051] S6. Prepare the quantum dot semiconductor layer by printing on the oxide semiconductor layer prepared in S5.

[0052] S7. Anneal the quantum dot semiconductor layer prepared in S6 in air.

[0053] S8. Deposit a conductive film on the semiconductor layer in S7 as the source 14a / drain 14b.

[0054] S9. Anneal the device in S8 in air to obtain the printable synaptic transistor of the present invention.

[0055] Among them, the prepared thickness of the electret dielectric layer 12 in S2 is 100 nm, and the capacitance per unit area of the electret dielectric layer 12 is about 200 nF / cm 2 .

[0056] In S3, the annealing temperature is between 50 °C and 200 °C, and the annealing time is between 0.5 h and 1 h.

[0057] In S4, a 20-nm oxide semiconductor layer is prepared by printing, and the semiconductor layer contains at least one of indium element oxide, zinc element oxide, gallium element oxide, tin element oxide, or cadmium element oxide.

[0058] In S7, a 20-nm-thick quantum dot semiconductor layer is prepared by printing, and the quantum dots contain at least one of lead element, cadmium element, selenium element, tellurium element, zinc element, sulfur element, indium element, and phosphorus element.

[0059] The bending situation of the energy band when the printable synaptic transistor obtained in this embodiment is operating is as Figure 3 shown.

[0060] Through Figure 3It can be seen that when a narrow-bandgap quantum dot semiconductor is in contact with a wide-bandgap semiconductor, the energy band is significantly bent. When light irradiates the printable synaptic transistor, due to the narrow bandgap characteristics of the quantum dots and the relatively high concentration of electrons in the oxide, even photons with small energy can be absorbed, and a large number of electrons are excited to jump from the top of the valence band to the bottom of the conduction band, achieving efficient transmission.

[0061] Example 3

[0062] A printable synaptic transistor based on a dual active layer of a wide-bandgap oxide and a narrow-bandgap quantum dot, with other features the same as in Example 2, except that: the preparation process of the printable synaptic transistor in this example includes the following steps:

[0063] S1. Prepare a 150-nm indium tin oxide thin film ITO as the gate on the glass substrate 10 by sputtering.

[0064] S2. Prepare a 100-nm thick polyvinylpyrrolidone thin film PVP on the glass substrate 10 by spin coating to form an electret dielectric layer 12.

[0065] The structural formula of polyvinylpyrrolidone is as follows:

[0066]

[0067] S3. Prepare a 20-nm thick IaGaInO4 thin film IGZO by sputtering, and pattern it by means of a mask to form an oxide semiconductor layer.

[0068] S4. Prepare a 20-nm thick lead sulfide PbS quantum dot by spin coating to form a quantum dot semiconductor layer.

[0069] The transfer characteristic curve and output characteristic curve of the printable synaptic transistor obtained in this example are as Figure 4 shown.

[0070] Through Figure 4 it can be seen that the gate 11 voltage is controlled within 5 V, and the on-off ratio is greater than 10 4 , which means that there is a current regulation effect in a range of more than 4 orders of magnitude.

[0071] The synaptic performance of the printable synaptic transistor obtained in this example under electrical signal stimulation is obtained Figure 5 .

[0072] Through Figure 5 it can be seen that the PPF index obtained by the printable synaptic transistor of the present invention is A2 / A1 = 258%, which proves that the dual active layer printable synaptic transistor of the wide-bandgap oxide and the narrow-bandgap quantum dot can obtain high-reliability synaptic plasticity.

[0073] The synaptic performance of the printable synaptic transistor obtained in this embodiment under ultra-wide spectral signal stimulation was obtained Figures 6 to 8 .

[0074] Through Figures 6 to 8 It can be seen that the printable synaptic transistor responds to ultraviolet light, visible light, and near-infrared light, and exhibits different current magnitudes, demonstrating the wide spectral response characteristics of the printable synaptic transistor of the present invention and its selectivity for different light wavelengths.

[0075] In summary, the printable synaptic transistor of the present invention can perform electrical signal regulation with a source-drain voltage below 5V and an active layer in a range greater than 4 orders of magnitude, as well as ultra-wide spectral optical signal regulation of the active layer 13 from ultraviolet to near-infrared. This printable synaptic transistor synergistically utilizes the high mobility of the oxide semiconductor and the wide spectral absorption characteristics of the quantum dots, and combines energy band engineering design to achieve efficient separation and transport of photo-generated carriers, thereby enhancing the optoelectronic response range and energy efficiency of the device. At the same time, the printable synaptic transistor of the present invention uses a solution-processable high-k polymer electret as the dielectric layer, which not only realizes low-voltage driving and non-volatile polarization storage, but also can achieve integrated patterning of the gate, source / drain electrodes through a printing process, avoiding complex alignment steps and significantly reducing the manufacturing cost. Therefore, the printable synaptic transistor of the present invention can provide core device support for the next generation of low-power, multi-modal sensing, storage, and computing technologies, and promote the development of wearable electronics towards a more intelligent and human-friendly direction.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A printable synaptic transistor based on a double active layer of wide-bandgap oxide and narrow-bandgap quantum dots, provided with a glass substrate, a dielectric layer, an active layer, a source electrode, a gate electrode, and a drain electrode, characterized in that: The active layer contains a wide-bandgap oxide and narrow-bandgap quantum dots, so that the printable synaptic transistor operates through the high mobility characteristics of the wide-bandgap oxide, and a wide-spectrum response is generated through the narrow bandgap characteristics of the narrow-bandgap quantum dots; The dielectric layer is an electret dielectric layer, and the electret dielectric layer regulates the electron concentration of the active layer through polarization.

2. The printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots according to claim 1, wherein: The wide-bandgap oxide forms an oxide semiconductor layer; The narrow-bandgap quantum dots form a quantum dot semiconductor layer; The oxide semiconductor layer and the quantum dot semiconductor layer are stacked to form a dual-active layer structure.

3. The printable synaptic transistor based on a double active layer of wide-bandgap oxide and narrow-bandgap quantum dots according to claim 1, wherein: The wide-bandgap oxide is at least one of an In element oxide, a Zn element oxide, a Ga element oxide, a Sn element oxide, or a Cd element oxide.

4. The printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots according to claim 1, wherein: The narrow-bandgap quantum dots contain at least one of Pb element, Cd element, Se element, Te element, Zn element, S element, In element, or P element.

5. The printable synaptic transistor based on a dual active layer of wide bandgap oxide and narrow bandgap quantum dots according to claim 2, wherein: The oxide semiconductor layer is prepared by a printing method.

6. The printable synaptic transistor based on a dual active layer of wide-bandgap oxide and narrow-bandgap quantum dots according to claim 2, wherein: The quantum dot semiconductor layer is processed from an inorganic quantum dot solution.

7. The printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots according to claim 1, wherein: The electret dielectric layer is processed from a polymer solution.

8. The printable synaptic transistor based on a double active layer of wide bandgap oxide and narrow bandgap quantum dots according to claim 7, characterized in that: The polymer contains at least one of strong polar groups such as an amide group, a cyano group, an amino group, or a hydroxyl group.

9. The printable synaptic transistor based on a dual active layer of wide bandgap oxide and narrow bandgap quantum dots according to claim 2, wherein: The preparation order from front to back is the gate, the electret dielectric layer, the oxide semiconductor layer, the quantum dot semiconductor layer, and finally the source electrode and the drain electrode are prepared.

10. The printable synaptic transistor based on a dual active layer of wide bandgap oxide and narrow bandgap quantum dots according to any one of claims 1 to 9, characterized in that: When the source-drain voltage is below 5V, the active layer conducts electrical signal regulation in a range greater than 4 orders of magnitude, and the active layer conducts ultra-wide spectrum optical signal regulation from ultraviolet to near infrared.

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