Heterogeneous composite photoelectric detector with top gate structure and preparation method thereof
By forming an ion-electron-bound state structure between graphene and superion conductor RbAg4I5 and building a top gate structure, the problem of degradation in performance of traditional photodetectors on the nanoscale is solved, and a high sensitivity and fast response photoelectric detection effect is achieved.
Patent Information
- Application Number
- CN202510046586.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-04-15
AI Technical Summary
Traditional silicon-based photodetectors have deteriorated performance on the nanoscale, making it difficult to achieve high sensitivity, miniaturization and intelligence. There are shortcomings in the regulation and balance of performance of two-dimensional material photodetectors.
By forming an ion-electron bound state structure between graphene and superion conductor RbAg4I5 and building a top gate structure, an electric field is applied to adjust the bound energy of the bound state, and dynamic regulation of photoelectric performance is achieved.
It significantly improves the responsiveness and response time of the photodetector, breaks through the performance bottleneck of existing light detection technologies, and provides a new technical path for tunable optoelectronic devices.
Smart Images
Figure CN119836116A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of micro-nano photoelectric detectors, and in particular to a heterogeneous composite photoelectric detector with a top-gate structure and a preparation method thereof. Background Art
[0002] As an important bridge between optoelectronic technology and electronic technology, photodetectors can convert optical signals into electrical signals and have been widely used in optical communications, medical diagnosis, military defense, aerospace, and environmental monitoring. With the rapid development of photodetection technology, photodetectors have achieved wide-spectrum detection of ultraviolet light, visible light, infrared light, and even terahertz electromagnetic waves. However, traditional silicon-based photodetectors are gradually approaching their physical limits. Limited by the constraints of Moore's Law, they are difficult to meet the growing demand for high-sensitivity, miniaturized, and intelligent light detection. Especially when the device size is reduced to the nanoscale, the performance of traditional optoelectronic devices often decreases significantly. At the same time, it is difficult to achieve efficient integration and multifunctionality, which limits its further application potential.
[0003] In recent years, photodetectors based on atomically thin two-dimensional materials have become a research hotspot due to their excellent optoelectronic properties and miniaturization advantages. This type of material has unique light-matter interaction characteristics, can efficiently convert optical signals at the nanoscale, and exhibits a wide spectral response range and fast response characteristics. Among many two-dimensional materials, graphene has become an ideal candidate material for the research of a new generation of photodetectors due to its high carrier mobility, wide spectral absorption, and adjustable band gap. However, the light absorption rate of a single layer of graphene is only 2.3%, and its short photocarrier lifetime limits the realization of high responsiveness. In addition, the photoelectric conversion mechanism of traditional two-dimensional material photodetectors (such as photoconductivity effect, grating effect, etc.) also has efficiency bottlenecks, making it difficult to simultaneously optimize key performance parameters such as responsiveness, photoelectric conversion efficiency, and response time.
[0004] To overcome these problems, researchers have proposed a method to improve the performance of graphene-based heterogeneous composite materials. These composite materials deposit other low-dimensional materials (such as quantum dots, one-dimensional nanowires or two-dimensional layered materials) on the surface of graphene, and use the synergistic effect of heterojunctions to significantly improve the sensitivity of the device. However, even so, these improvements have not fundamentally solved the shortcomings of two-dimensional material photodetectors in regulating performance balance.
[0005] Superionic conductors are a class of materials with ions as the main charge carriers and high ion mobility, including ionic liquids, solid electrolytes and superionic conductors. Superionic conductors not only exhibit high mobility close to that of ionic liquids, but also have the mechanical stability and easy integration of solid materials. Studies have shown that combining superionic conductors with two-dimensional materials with high electronic conductivity can form ion-electron bound states (IEBS) at the interface due to Coulomb interactions. This bound state can be activated by light or electric fields, and by regulating the interaction mechanism between ions and electrons, it provides innovative ideas for the development of new photodetectors. Under illumination conditions, this coupled state can be dissociated by photons, thereby generating significant photocurrent, and the ions do not directly participate in the conduction of current, thus retaining the advantages of efficient electronic conduction of two-dimensional materials.
[0006] The existing research on graphene / superionic conductor composite photodetectors has made some progress, but it mainly focuses on the effect of light field on bound states, and there is relatively little research on electric field regulation. In particular, the effect of applying an external electric field on the energy of bound states and ion movement using a top gate structure has not been explored in depth. By introducing a top gate structure, not only can the responsivity and response time of the photodetector be effectively regulated, but the controllability of the device can also be further improved.
[0007] The present invention proposes a photodetector based on a graphene / RbAg4I5 composite material. By constructing a top gate structure on the composite material and applying an electric field to adjust the binding energy of the ion-electron bound state, the photoelectric performance of the device can be dynamically controlled. Under light, the bound state at the interface of the composite material is activated and dissociated by photons, generating a significant photocurrent. The application of the top gate voltage further regulates the movement of ions and the coupling strength between ions and electrons, so that the device shows significant improvements in both responsiveness and response time. This new photodetector not only breaks through the performance bottleneck of existing photodetection technology, but also provides a new technical path for the development of tunable photoelectric devices. Summary of the invention
[0008] The present invention proposes a heterogeneous composite photodetector with a top-gate structure and a preparation method thereof. By forming an ion-electron bound state (IEBS) structure between the two-dimensional material graphene and the superionic conductor material RbAg4I5, the photoelectric response performance and sensitivity of the photodetector can be effectively improved, especially in terms of photoelectric response speed and detection sensitivity.
[0009] The present invention adopts the following technical solutions.
[0010] A top-gate heterogeneous composite photodetector, which is a top-gate heterogeneous composite phototransistor, includes a heterostructure formed by the composite of an electronic conductor graphene and a superionic conductor RbAg4I5, and a top-gate top-contact structure on the surface of the heterostructure; the heterostructure forms a photoelectric response mechanism through the interaction between electrons of the electronic conductor and ions of the superionic conductor.
[0011] The heterostructure breaks the balance between response rate and response speed in the traditional junction-type photoelectric response process through a photoelectric response mechanism, so as to optimize the device performance of the photodetector.
[0012] When the photodetector is working, the top-gate top-contact structure applies a top-gate electric field to the heterostructure composite material in the phototransistor to regulate the migration of ions in the superionic conductor material and controllably adjust the device performance.
[0013] The electronic conductor graphene is a two-dimensional material, and an ion-electron bound state structure IEBS is formed between the two-dimensional material graphene and the superionic conductor material RbAg4I5.
[0014] When the photodetector is illuminated by light, the bound states at the interface of the heterostructure composite material are activated by photons to dissociate, generating photocurrent. The top gate voltage of the top gate electric field is used to regulate the movement of ions and the coupling strength between ions and electrons to improve the responsiveness and response time of the device.
[0015] A method for preparing a heterogeneous composite photodetector with a top-gate structure, the method being used to prepare a heterogeneous composite device structure of an electronic conductor and a superionic conductor based on ion regulation, comprising the following steps;
[0016] Step S1, selecting an electronic conductor as a two-dimensional material, and transferring it to a pretreated substrate through a wet transfer process;
[0017] Step S2, depositing noble metal electrodes at both ends of the electronic conductor two-dimensional material at the substrate by using a thermal evaporation process;
[0018] Step S3, vertically depositing superionic conductor material by vacuum thermal evaporation to form a superionic conductor film, obtaining an ionic material / two-dimensional material heterogeneous composite structure, and forming an interaction between electrons and ions at the composite interface;
[0019] Step S4, depositing a high-k dielectric layer on the surface of the superionic conductor film, wherein the high-k dielectric layer is prepared by a magnetron sputtering method;
[0020] Step S5, continuing to deposit a transparent conductive layer on the surface of the high-k dielectric layer, the conductive layer is deposited by a magnetron sputtering method to form an electronic conductor and superionic conductor heterocomposite device structure based on ion regulation, and finally obtaining a heterocomposite composite material type photodetector device with a top gate structure.
[0021] In step S1, the electronic conductor is a graphene two-dimensional material.
[0022] In step S3, the superionic conductor material is a RbAg4I5 thin film.
[0023] In step S4, the high-k dielectric layer is an Al2O3 film.
[0024] In step S5, the transparent conductive layer is an ITO film.
[0025] The present invention proposes a photodetector based on a graphene / RbAg4I5 composite material. By constructing a top gate structure on the composite material and applying an electric field to adjust the binding energy of the ion-electron bound state, the photoelectric performance of the device can be dynamically controlled. Under light, the bound state at the interface of the composite material is activated and dissociated by photons, generating a significant photocurrent. The application of the top gate voltage further regulates the movement of ions and the coupling strength between ions and electrons, so that the device shows significant improvements in both responsiveness and response time. This new photodetector not only breaks through the performance bottleneck of existing photodetection technology, but also provides a new technical path for the development of tunable photoelectric devices.
[0026] The beneficial effects of the present invention are:
[0027] 1. The present invention prepares a top-gate photodetector by constructing a graphene / RbAg4I5 heterojunction. The device breaks the traditional photoelectric response mechanism of existing junction-type devices and realizes photoelectric response by using the electron-ion interaction mechanism;
[0028] 2. The present invention constructs a heterojunction by introducing RbAg4I5 thin film, combines its high ionic conductivity and low electronic conductivity characteristics, and accurately adjusts the ion movement by changing the gate voltage, thereby changing the interaction process between electrons and ions, thereby achieving efficient control of photocurrent and response rate without affecting the response speed;
[0029] 4. The top gate structure prepared by the present invention forms a transparent conductive layer (ITO) and a high-k dielectric layer (Al2O3) on the surface of the composite material by magnetron sputtering, which optimizes the conductive channel and interface stability of the device, ensures the sensitivity of gate-controlled modulation, and maintains the high stability and repeatability of the photodetector;
[0030] 5. The graphene / RbAg4I5 heterojunction photodetector of the present invention demonstrates the unique regulatory mechanism of ion-electron interaction on photoelectric performance, provides a theoretical basis and practical solution for the design of new photoelectric devices based on ion-electron coupling, can be widely used in photoelectric detection, information storage and other related fields, and has important academic and industrial value. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:
[0032] Attached Figure 1 It is a schematic diagram of the preparation process of a heterogeneous composite photodetector with a top-gate structure;
[0033] Attached Figure 2 is a schematic diagram of the Raman spectrum of the graphene film prepared in the embodiment;
[0034] Attached Figure 3 Schematic diagram of the output characteristic curve of the heterogeneous composite photodetector with a top-gate structure prepared in the embodiment;
[0035] Attached Figure 4 Schematic diagram of the transfer characteristic curve of the heterogeneous composite photodetector with a top-gate structure prepared in the embodiment;
[0036] Attached Figure 5 is a schematic diagram of a light response test of a heterogeneous composite photodetector with a top-gate structure prepared in the embodiment;
[0037] Attached Figure 6 It is a schematic diagram of the photocurrent and response rate of the heterogeneous composite photodetector with a top-gate structure prepared in the embodiment. DETAILED DESCRIPTION
[0038] As shown in the figure, a top-gate heterogeneous composite photodetector is provided. The photodetector is a top-gate heterogeneous composite phototransistor, including a heterostructure formed by a composite of an electronic conductor graphene and a superionic conductor RbAg4I5, and a top-gate top-contact structure on the surface of the heterostructure. The heterostructure forms a photoelectric response mechanism through the interaction between electrons of the electronic conductor and ions of the superionic conductor.
[0039] The heterostructure breaks the balance between response rate and response speed in the traditional junction-type photoelectric response process through a photoelectric response mechanism, so as to optimize the device performance of the photodetector.
[0040] When the photodetector is working, the top-gate top-contact structure applies a top-gate electric field to the heterostructure composite material in the phototransistor to regulate the migration of ions in the superionic conductor material and controllably adjust the device performance.
[0041] The electronic conductor graphene is a two-dimensional material, and an ion-electron bound state structure IEBS is formed between the two-dimensional material graphene and the superionic conductor material RbAg4I5.
[0042] When the photodetector is illuminated by light, the bound states at the interface of the heterostructure composite material are activated by photons to dissociate, generating photocurrent. The top gate voltage of the top gate electric field is used to regulate the movement of ions and the coupling strength between ions and electrons to improve the responsiveness and response time of the device.
[0043] A method for preparing a heterogeneous composite photodetector with a top-gate structure, the method being used to prepare a heterogeneous composite device structure of an electronic conductor and a superionic conductor based on ion regulation, comprising the following steps;
[0044] Step S1, selecting an electronic conductor as a two-dimensional material, and transferring it to a pretreated substrate through a wet transfer process;
[0045] Step S2, depositing noble metal electrodes at both ends of the electronic conductor two-dimensional material at the substrate by using a thermal evaporation process;
[0046] Step S3, vertically depositing superionic conductor material by vacuum thermal evaporation to form a superionic conductor film, obtaining an ionic material / two-dimensional material heterogeneous composite structure, and forming an interaction between electrons and ions at the composite interface;
[0047] Step S4, depositing a high-k dielectric layer on the surface of the superionic conductor film, wherein the high-k dielectric layer is prepared by a magnetron sputtering method;
[0048] Step S5, continuing to deposit a transparent conductive layer on the surface of the high-k dielectric layer, the conductive layer is deposited by a magnetron sputtering method to form an electronic conductor and superionic conductor heterocomposite device structure based on ion regulation, and finally obtaining a heterocomposite composite material type photodetector device with a top gate structure.
[0049] In step S1, the electronic conductor is a graphene two-dimensional material.
[0050] In step S3, the superionic conductor material is a RbAg4I5 thin film.
[0051] In step S4, the high-k dielectric layer is an Al2O3 film.
[0052] In step S5, the transparent conductive layer is an ITO film.
[0053] Example:
[0054] In this case, an ion-electron bound state (IEBS) structure is formed between the two-dimensional material graphene and the superionic conductor material RbAg4I5, which can effectively improve the photoelectric response performance and sensitivity of the photodetector.
[0055] In this example, a method for preparing a top-gate heterogeneous composite material type photodetector comprises the following steps:
[0056] 1) transferring the electronic conductor two-dimensional material to the pre-treated substrate through a wet transfer process;
[0057] 2) Depositing precious metal electrodes on both ends of the electronic conductor graphene using a thermal evaporation process;
[0058] 3) Using vacuum thermal evaporation to vertically deposit superionic conductor materials, obtain ionic material / two-dimensional material heterogeneous composite structures, and form interactions between electrons and ions at the composite interface;
[0059] 4) depositing a high-k dielectric layer on the surface of the superionic conductor film, wherein the high-k dielectric layer is prepared by a magnetron sputtering method;
[0060] 5) A transparent conductive layer is continuously deposited on the surface of the high-k dielectric layer. The conductive layer is deposited by a magnetron sputtering method to finally obtain a heterogeneous composite material type photodetector device with a top gate structure.
[0061] Furthermore, in step 1), the two-dimensional material is graphene.
[0062] Furthermore, in step 3), the superionic conductor material is RbAg4I5 thin film.
[0063] Furthermore, in step 5), the high-k dielectric layer is an Al2O3 film.
[0064] Furthermore, in step 6), the transparent conductive layer is an ITO film.
[0065] The specific process is as follows:
[0066] Step 1) Pre-treating a highly doped p-type silicon-based substrate with a 300 nm oxide layer: ultrasonically cleaning the substrate with propanol and anhydrous ethanol in sequence, then using deionized water to clean the residual cleaning agent, and finally leaving a silicon-based substrate with a clean surface.
[0067] Step 2) Transfer the two-dimensional material to the pre-treated silicon-based substrate using a wet transfer process: Place the two-dimensional material / PMMA structure in a 1 mol / L FeCl3 solution to etch the copper foil, then rinse with deionized water, repeat three times for ten minutes each time to remove the residual etchant. After using the silicon-based substrate to hold up the two-dimensional material / PMMA structure, immerse it in acetone to dissolve PMMA, complete the transfer of graphene, and obtain a two-dimensional material / substrate structure.
[0068] Step 3) Vacuum thermal evaporation is used, and the vacuum degree of the deposition process is controlled at 10 -4 Pa, a 50nm silver film is deposited on both ends of the two-dimensional material to form an electrode pair with a spacing of 3mm to constitute a conductive channel.
[0069] Step 4) depositing a RbAg4I5 thin film on the surface of the two-dimensional material by vacuum thermal evaporation to obtain an ionic material / two-dimensional material heterogeneous composite structure.
[0070] Step 5) placing the ionic material / two-dimensional material composite material in a vacuum environment and allowing it to stand to form an interactive bound state of ions and electrons at the interface.
[0071] Step 6) depositing an Al2O3 thin film on the surface of the heterogeneous composite material by magnetron sputtering to form a high-k dielectric layer.
[0072] Step 7) Continue to deposit a transparent conductive ITO film on the surface of the high-k dielectric layer by magnetron sputtering to complete the preparation of the top gate structure, thereby completing the preparation of the device.
[0073] The electrical performance of the prepared top-gate heterogeneous composite material photodetector was tested using a source meter, and the output characteristic curve of the device was analyzed. Figure 3 and Figure 4 They are respectively the output characteristic curve and the transfer characteristic curve of the heterogeneous composite photodetector with a top gate structure prepared in Example 1.
[0074] Figure 5 This is a light response test diagram of the top-gate heterogeneous composite material photodetector prepared in Example 1. Under 532nm laser irradiation and a fixed light power of 10mW, the photocurrent gradually decreases as the gate voltage increases. Further analysis of the light response characteristics under different fixed light powers shows that the change trend of the photocurrent remains consistent.
[0075] Figure 6 The characteristics of the device's photocurrent and response rate at 10mW light power as a function of gate voltage are shown. As the gate voltage increases, the photocurrent gradually decreases. Positive gate voltage effectively regulates the device's photoelectric performance by enhancing electron-ion interaction, providing adjustability for the application of photodetectors under specific light power and electric field conditions.
Claims
1. A top-gate heterogeneous composite photodetector, characterized in that: The photodetector is a top-gate heterogeneous composite phototransistor, including a heterostructure formed by a composite of an electronic conductor graphene and a superionic conductor RbAg4I5, and a top-gate top-contact structure on the surface of the heterostructure; the heterostructure forms a photoelectric response mechanism through the interaction between electrons of the electronic conductor and ions of the superionic conductor.
2. The heterogeneous composite photodetector with a top-gate structure according to claim 1, characterized in that: The heterostructure breaks the balance between response rate and response speed in the traditional junction-type photoelectric response process through a photoelectric response mechanism, so as to optimize the device performance of the photodetector.
3. The heterogeneous composite photodetector with a top-gate structure according to claim 1, characterized in that: When the photodetector is working, the top-gate top-contact structure applies a top-gate electric field to the heterostructure composite material in the phototransistor to regulate the migration of ions in the superionic conductor material and controllably adjust the device performance.
4. The top-gate heterogeneous composite photodetector according to claim 3, characterized in that: The electronic conductor graphene is a two-dimensional material, and an ion-electron bound state structure IEBS is formed between the two-dimensional material graphene and the superionic conductor material RbAg4I5.
5. The heterogeneous composite photodetector with a top-gate structure according to claim 4, characterized in that: When the photodetector is illuminated by light, the bound states at the interface of the heterostructure composite material are activated by photons to dissociate, generating photocurrent. The top gate voltage of the top gate electric field is used to regulate the movement of ions and the coupling strength between ions and electrons to improve the responsiveness and response time of the device.
6. A method for preparing a heterogeneous composite photodetector with a top-gate structure, characterized in that: The preparation method is used to prepare a heterogeneous composite device structure of an electronic conductor and a superionic conductor based on ion regulation. The steps include: Step S1, selecting an electronic conductor as a two-dimensional material, and transferring it to a pretreated substrate through a wet transfer process; Step S2, depositing noble metal electrodes at both ends of the electronic conductor two-dimensional material at the substrate by using a thermal evaporation process; Step S3, vertically depositing superionic conductor material by vacuum thermal evaporation to form a superionic conductor film, obtaining an ionic material / two-dimensional material heterogeneous composite structure, and forming an interaction between electrons and ions at the composite interface; Step S4, depositing a high-k dielectric layer on the surface of the superionic conductor film, wherein the high-k dielectric layer is prepared by a magnetron sputtering method; Step S5, continuing to deposit a transparent conductive layer on the surface of the high-k dielectric layer, the conductive layer is deposited by a magnetron sputtering method to form an electronic conductor and superionic conductor heterocomposite device structure based on ion regulation, and finally obtaining a heterocomposite composite material type photodetector device with a top gate structure.
7. The method for preparing a heterogeneous composite photodetector with a top-gate structure according to claim 6, characterized in that: In step S1, the electronic conductor is a graphene two-dimensional material.
8. The method for preparing a heterogeneous composite photodetector with a top-gate structure according to claim 6, characterized in that: In step S3, the superionic conductor material is a RbAg4I5 thin film.
9. The method for preparing a heterogeneous composite photodetector with a top-gate structure according to claim 6, characterized in that: In step S4, the high-k dielectric layer is an Al2O3 film.
10. The method for preparing a heterogeneous composite photodetector with a top-gate structure according to claim 6, characterized in that: In step S5, the transparent conductive layer is an ITO film.