High-dielectric LaNb2O7 heterostructure dual-band photoelectric detector and application thereof
By constructing a LaNb2O7-SnS2 heterostructure photodetector on a two-dimensional semiconductor, the challenge of integrating high dielectric materials was solved, high dielectric properties and excellent photoelectric properties were achieved, and its application in phototransistors and imaging sensors was expanded.
Patent Information
- Application Number
- CN202511155353.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-18
- Publication Date
- 2025-09-19
AI Technical Summary
In the existing technology, how to integrate high-dielectric materials on two-dimensional semiconductors to improve device performance and reduce power consumption still remains a challenge, especially in terms of the compatibility and lattice matching between two-dimensional semiconductors and high-dielectric layers.
Through a lossless transfer process, high-dielectric LaNb2O7 nanosheets and two-dimensional semiconductor SnS2 nanosheets are constructed into a LaNb2O7-SnS2 heterostructure to form a photodetector, achieving a step-by-step photoresponse to ultraviolet and visible light.
It achieves high dielectric properties and excellent visible light and ultraviolet light detection capabilities, expands the application of two-dimensional perovskite LaNb2O7 photodetectors in phototransistors and imaging sensors, and has good photoelectric performance and high detection rate.
Smart Images
Figure CN120676724A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present disclosure belong to the technical field of photoelectric detectors, and specifically relate to a high-dielectric LaNb2O7 heterostructure dual-band photoelectric detector and its application. Background Art
[0002] Two-dimensional semiconductors have significant potential as channel materials for multifunctional optoelectronic devices. Their compatibility with high-k dielectrics is crucial for integrated electronic and optoelectronic devices. To improve device performance while reducing power consumption, integrated devices require high gate capacitance. Integrating high-k dielectrics with two-dimensional semiconductors via a lossless transfer process has shown promise, effectively circumventing lattice matching issues and process compatibility challenges. Achieving a balance between bandgap and dielectric constant is key to achieving monolithic integrated multifunctional devices, and integrating high-k dielectrics onto two-dimensional semiconductors remains a significant challenge.
[0003] Layered niobate perovskites are considered a class of dielectric materials with great application prospects. Extensive research has been conducted on the dielectric properties of two-dimensional perovskite niobates with different crystal structures, tunable compositions, and varying thicknesses. Nanosheets obtained by exfoliating layered perovskite niobates can be used as excellent dielectric materials, exhibiting high dielectric constants, low leakage currents, and wide band gaps. Furthermore, two-dimensional perovskite niobates are also UV-sensitive. Therefore, developing an integrated multifunctional device in which LaNb2O7 nanosheets serve as both a high-dielectric gate and a UV-sensitive material has important scientific and practical significance. Summary of the Invention
[0004] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a high-dielectric LaNb2O7 heterostructure dual-band photodetector and its application.
[0005] An embodiment of the present disclosure provides a high-dielectric LaNb2O7 heterostructure dual-band photodetector, which includes a substrate, a LaNb2O7-SnS2 heterostructure, and a metal electrode arranged in sequence; wherein the photodetector forms a step-like light response in the ultraviolet light band and the visible light band.
[0006] In some embodiments of the present disclosure, under 500 nm light, the responsivity of the photodetector is 0.9 A / W, and the detectivity of the photodetector is 2.7×10 10 Jones.
[0007] In some embodiments of the present disclosure, under 300 nm light, the responsivity of the photodetector is 157.9 A / W, and the detectivity of the photodetector is 4.7×10 12 Jones.
[0008] In some embodiments of the present disclosure, LaNb2O7 nanosheets and SnS2 nanosheets are constructed by laser direct writing to form the LaNb2O7-SnS2 heterostructure.
[0009] In some embodiments of the present disclosure, the LaNb2O7 nanosheets are prepared by solid-phase sintering and liquid-phase exfoliation.
[0010] In some embodiments of the present disclosure, the SnS2 nanosheets are obtained by artificial mechanical tape exfoliation.
[0011] In some embodiments of the present disclosure, the dielectric constant of the LaNb2O7 nanosheets is 34.8.
[0012] In some embodiments of the present disclosure, a single LaNb2O7 nanosheet is used as the top gate of the SnS2 nanosheet, and the on / off ratio of the transistor of the SnS2 nanosheet is 10 4 .
[0013] The second aspect of the present disclosure proposes an application of a high-dielectric LaNb2O7 heterostructure dual-band photodetector, using the photodetector described in any of the above embodiments for a phototransistor, or using the photodetector described in any of the above embodiments for visible light and ultraviolet light detection imaging.
[0014] This disclosure proposes a high-dielectric LaNb2O7 heterostructure dual-band photodetector and its applications. The photodetector is constructed using a LaNb2O7-SnS2 heterostructure, exhibiting a stepped photoresponse in the ultraviolet and visible light bands. This photodetector, constructed based on the LaNb2O7-SnS2 heterostructure, exhibits excellent visible and ultraviolet light detection capabilities and high dielectric properties. It can be applied to visible and ultraviolet imaging sensors and phototransistors, greatly expanding the application of this two-dimensional perovskite LaNb2O7 photodetector in many fields. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 The morphology of the LaNb2O7 nanosheets of the embodiment of the present disclosure is characterized; wherein, Figure 1 (a) is a scanning electron microscope image of LaNb2O7 nanosheets; Figure 1 (b) is an optical microscope image of LaNb2O7 nanosheets; Figure 1 (c) is an atomic force microscope image of LaNb2O7 nanosheets; Figure 2 The dielectric properties of the LaNb2O7 nanosheets of the embodiment of the present disclosure are characterized; wherein, Figure 2(a) is an atomic force microscope image of LaNb2O7 nanosheets; Figure 2 (b) is the voltage value of the electrostatic force signal when the tip-sample distance is 10 nm (corresponding to Figure 2 a's position); Figure 2 (c) shows the experimental data and fitting curve of the relationship between the electrostatic force signal and the tip-sample distance; Figure 3 The performance of the SnS2 transistor with LaNb2O7 as the top gate according to the embodiment of the present disclosure; Figure 3 (a) is a schematic diagram of the LaNb2O7-SnS2 heterostructure device; Figure 3 (b) is an optical image of a field-effect transistor using LaNb2O7 top-gate dielectric; Figure 3 (c) in the figure is the transfer characteristic curve of the transistor measured at different voltages; Figure 4 The performance of the LaNb2O7-SnS2 heterojunction dual-band photodetector according to the embodiment of the present disclosure is studied; Figure 4 (a) is a schematic diagram of the structure of a dual-band photodetector; Figure 4 (b) shows the current-voltage characteristic curve of the device under 500 nm and 300 nm light illumination; Figure 4 (c) shows the current-time characteristic curves of the device under 500 nm light at different voltages; Figure 4 (d) shows the current-time characteristic curves of the device under 300 nm light illumination at different voltages; Figure 4 (e) in the figure is the responsivity of the device in the wavelength range of 300-600 nm under a bias of 3 V; Figure 4 (f) in the figure is the detectivity of the device in the wavelength range of 300-600 nm under a bias of 3V. DETAILED DESCRIPTION
[0016] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are not intended to limit the disclosure. The described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without the need for creative work are within the scope of protection of the present disclosure.
[0017] An embodiment of the present disclosure provides a high-dielectric LaNb2O7 heterostructure dual-band photodetector, wherein the photodetector is constructed of a LaNb2O7-SnS2 heterostructure; wherein the photodetector forms a step-type light response in the ultraviolet light band and the visible light band.
[0018] The present invention discloses a photodetector based on a LaNb2O7-SnS2 heterostructure. The photodetector has excellent visible light and ultraviolet light detection capabilities and high dielectric properties. It can be applied to visible light, ultraviolet light imaging sensors, and phototransistors, greatly expanding the application of the two-dimensional perovskite LaNb2O7 photodetector in many fields.
[0019] In some embodiments of the present disclosure, under 500 nm light, the responsivity of the photodetector is 0.9 A / W, and the detectivity of the photodetector is 2.7×10 10 Jones. This shows that the photodetector has good photoelectric performance under 500nm light conditions.
[0020] In some embodiments of the present disclosure, under 300 nm light, the responsivity of the photodetector is 157.9 A / W, and the detectivity of the photodetector is 4.7×10 12 Jones. This shows that the photodetector has good photoelectric performance under 300nm light conditions.
[0021] It should be understood that the photodetector includes a substrate, a LaNb2O7-SnS2 heterostructure and a metal electrode, such as Figure 3 (a) and Figure 4 As shown in (a), the photodetector of this embodiment is provided with a SiO2 / Si substrate 100 and a LaNb2O7-SnS2 heterostructure 200 in order from bottom to top, and a metal electrode 300 is provided on the LaNb2O7 nanosheet 220 and the SnS2 nanosheet 210 of the LaNb2O7-SnS2 heterostructure. Specifically, as Figure 3 As shown in (a), the photodetector has two metal electrodes, one of which is connected to the side of the SnS2 nanosheet 210 of the LaNb2O7-SnS2 heterostructure 200 facing away from the substrate and is spaced apart from the LaNb2O7 nanosheet 220, and the other metal electrode is connected to the side of the LaNb2O7 nanosheet 220 of the LaNb2O7-SnS2 heterostructure 200 facing away from the SnS2 nanosheet 210; Figure 4As shown in (a), the photodetector has three metal electrodes, two of which are connected to the side of the SnS2 nanosheet 210 of the LaNb2O7-SnS2 heterostructure 200 that faces away from the substrate. The two metal electrodes are located at opposite ends of the SnS2 nanosheet 210. The LaNb2O7 nanosheet 220 is spaced apart from the two metal electrodes. The remaining metal electrode is connected to the side of the LaNb2O7 nanosheet 220 of the LaNb2O7-SnS2 heterostructure 200 that faces away from the SnS2 nanosheet 210. In other preferred embodiments, the photodetector may also include other structures, which are not specifically limited.
[0022] In some embodiments of the present disclosure, LaNb2O7 nanosheets and SnS2 nanosheets are constructed by laser direct writing to form the LaNb2O7-SnS2 heterostructure. In the photodetector, the LaNb2O7 nanosheets are located on top of the SnS2 nanosheets, that is, on the side of the SnS2 nanosheets facing away from the substrate.
[0023] In some embodiments of the present disclosure, the LaNb2O7 nanosheets are prepared by solid-phase sintering and liquid-phase exfoliation. The preparation method of the LaNb2O7 nanosheets specifically includes the following steps: S100: Rb2CO3, La2CO3 and Nb2O5 were mixed in a molar ratio of 1:1:2 and fully ground, and calcined at 1100°C in an air environment of a muffle furnace for 24 hours to obtain RbLaNb2O7 product.
[0024] S200: placing the RbLaNb2O7 product in a HNO3 solution and shaking for 3 days to obtain a HLaNb2O7 product.
[0025] S300: placing the HLaNb2O7 product in a tetrabutylammonium hydroxide solution, shaking for 3 days, and washing by centrifugation to obtain LaNb2O7 nanosheets dispersed in ethanol after centrifugation washing.
[0026] In this embodiment, LaNb2O7 nanosheets are prepared by high-temperature calcination, protonation and liquid phase exfoliation, which is simple and easy to operate.
[0027] In some embodiments of the present disclosure, the dielectric constant of the LaNb2O7 nanosheets is 34.8, which indicates that the LaNb2O7 nanosheets have excellent gate dielectric capabilities.
[0028] In some embodiments of the present disclosure, the SnS2 nanosheets are obtained by artificial mechanical tape stripping, that is, the bulk material is thinned to a single layer or a few layers of nanosheets by repeated stripping with an adhesive tape.
[0029] In some embodiments of the present disclosure, a single LaNb2O7 nanosheet is used as the top gate of the SnS2 nanosheet, and the on / off ratio of the SnS2 nanosheet transistor is 10 4 .
[0030] In some embodiments of the present disclosure, the thickness of the LaNb2O7 nanosheets is 1-10 nm, and the lateral length of the LaNb2O7 nanosheets is 3-10 μm. The thickness of the SnS2 nanosheets is 1-10 nm, and the lateral length of the SnS2 nanosheets is 2-9 μm.
[0031] The second aspect of the present disclosure proposes an application of a high-dielectric LaNb2O7 heterostructure dual-band photodetector, using the photodetector described in any of the above embodiments for a phototransistor, or using the photodetector described in any of the above embodiments for visible light and ultraviolet light detection imaging.
[0032] The following will further illustrate the preparation method of LaNb2O7 nanosheets and the performance of the photodetector with reference to specific examples: Example 1: LaNb2O7 nanosheets are primarily prepared by solid-phase sintering and liquid-phase exfoliation. SnS2 nanosheets are primarily obtained by tape exfoliation. LaNb2O7 nanosheets and SnS2 nanosheets are fabricated using laser direct writing to form a LaNb2O7-SnS2 heterostructure.
[0033] like Figure 1 As shown in (a) to (c), the morphology of LaNb2O7 nanosheets is characterized by a distinct two-dimensional structure.
[0034] like Figure 2 As shown in Figure 2, LaNb2O7 nanosheets have a high dielectric constant. Figure 2 (c) shows the experimental data and fitting curve of the relationship between the electrostatic force signal and the tip-sample distance, and it can be obtained that the dielectric constant of LaNb2O7 nanosheets is 34.8.
[0035] Depend on Figure 3 It can be seen that LaNb2O7 nanosheets can be used as the top gate of SnS2 nanosheet transistors, which have a high on-off ratio of 10 4 .
[0036] like Figure 4 As shown in (a) to (f), the LaNb2O7-SnS2 heterostructure dual-band photodetector has stable photoresponse under both 500 nm and 300 nm illumination, and the device has a higher photocurrent at 300 nm. The photodetector has a responsivity of 0.9 A / W under 500 nm illumination and a detectivity of 2.7×10 10Jones; the responsivity under 300 nm light is 157.9 A / W, and the detectivity is 4.7×10 12 Jones, it can be seen that the device has higher responsivity and detectivity under 300nm light.
[0037] The present invention discloses a photodetector formed based on a LaNb2O7-SnS2 heterostructure. The LaNb2O7 nanosheets of the photodetector have a high dielectric constant, which enables the photodetector formed by the LaNb2O7-SnS2 heterostructure to have excellent transistor performance. At the same time, it has excellent visible light and ultraviolet light step-type dual-band detection capabilities, and can be applied to visible light, ultraviolet light imaging sensors, and phototransistors, greatly expanding the application of the two-dimensional perovskite LaNb2O7 photodetector in many fields.
[0038] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.
Claims
1. A high dielectric LaNb2O7 heterostructure dual-band photodetector, characterized in that: The photodetector includes a substrate, a LaNb2O7-SnS2 heterostructure and a metal electrode arranged in sequence; wherein the photodetector forms a step-type light response in the ultraviolet light band and the visible light band.
2. The photodetector according to claim 1, wherein Under 500nm light, the responsivity of the photodetector is 0.9 A / W, and the detectivity of the photodetector is 2.7×10 10 Jones.
3. The photodetector according to claim 1, wherein Under 300nm light, the responsivity of the photodetector is 157.9A / W, and the detectivity of the photodetector is 4.7×10 12 Jones.
4. The photodetector according to claim 1, wherein The LaNb2O7-SnS2 heterostructure is formed by constructing LaNb2O7 nanosheets and SnS2 nanosheets by laser direct writing.
5. The photodetector according to claim 4, wherein: The LaNb2O7 nanosheets are prepared by solid-phase sintering and liquid-phase exfoliation.
6. The photodetector according to claim 4, wherein: The SnS2 nanosheets are obtained by artificial mechanical tape stripping.
7. The photodetector according to claim 4, wherein: The dielectric constant of the LaNb2O7 nanosheets is 34.
8.
8. The photodetector according to claim 4, wherein: The single LaNb2O7 nanosheet is used as the top gate of the SnS2 nanosheet, and the on / off ratio of the transistor of the SnS2 nanosheet is 10 4 .
9. An application of a high dielectric LaNb2O7 heterostructure dual-band photodetector, characterized in that: The photodetector according to any one of claims 1 to 8 is used in a phototransistor.
10. An application of a high dielectric LaNb2O7 heterostructure dual-band photodetector, characterized in that: The photoelectric detector according to any one of claims 1 to 8 is used in visible light and ultraviolet light detection imaging.