Method for manufacturing a lateral structure dual electrode device array based on laser etching

Abstract

This invention provides a method for fabricating a lateral dual-electrode device array based on laser etching. Utilizing the cumulative photothermal effect of pulsed laser during the etching process, an insulating channel is formed by etching a conductive layer with the pulsed laser. Simultaneously, the photothermal effect generated near the pulsed laser beam destroys the hydrophobic layer on both sides of the channel, thereby reducing its hydrophobic effect and forming a heat-affected zone (HAZ). When a solution capable of growing crystals using a solution method is coated onto the substrate, the presence of the HAZ ensures that the solution can wet and completely cover the laser-etched channel. Finally, the deposited crystalline film can laterally span both sides of the channel, forming a lateral dual-electrode device. According to the fabrication method of this invention, there is no need to separately prepare the array of active and electrode materials; only a single patterning process, laser etching, is required to complete the fabrication, achieving the fabrication of large-area, high-throughput, arrayed lateral dual-electrode devices.

Description

Technical Field

[0001] This invention relates to the field of microelectronic device array fabrication technology, and in particular to a method for fabricating a lateral structure dual-electrode device array based on laser etching. Background Technology

[0002] Fabrication techniques for lateral dual-electrode device arrays involve the arraying of active and electrode materials. The minimum processing precision of these two processes limits the cell area of ​​independently addressable device arrays. Existing arraying fabrication techniques mainly include: top-down etching methods such as laser etching, focused ion beam etching, and photolithography; bottom-up growth methods such as inkjet printing and nanoimprinting; and methods based on mask-based and space-physics-constrained processes such as evaporation, telemetry and control sputtering, and vapor deposition. These micro / nano fabrication methods can fabricate independently addressable device arrays, enabling the miniaturization, flexibility, and arraying of devices.

[0003] Photolithography boasts exceptional processing precision and is currently a high-end fabrication technology for miniaturized and arrayed devices. However, its commercial application is limited by drawbacks such as the poor compatibility of commonly used organic reagents like photoresists and developers with active materials, high equipment costs, and complex processing steps. Furthermore, techniques constrained by space physics, such as thermal evaporation, magnetron sputtering, and vapor deposition, often require custom masks, limiting their processing precision and resulting in long process cycles. Therefore, there is an urgent need for a low-cost, high-efficiency array fabrication technology to drive the miniaturization and arraying of electrode devices. Summary of the Invention

[0004] This invention provides a method for fabricating a lateral dual-electrode device array based on laser etching, thereby addressing at least one of the problems existing in related technologies. To achieve this objective, this invention employs the following technical solution.

[0005] This invention provides a method for fabricating a lateral dual-electrode device array based on laser etching, comprising:

[0006] Step 1: Provide a substrate with a conductive layer, and form a hydrophobic layer on the conductive layer;

[0007] Step 2: The substrate is etched using a pulsed laser, wherein the energy of the center of the pulsed laser spot is used to etch the hydrophobic layer and the conductive layer to form a split annular first channel array, and the photothermal effect of the pulsed laser is used to destroy the hydrophobic layer on both sides of the first channel to form a heat-affected zone. The first channel and the heat-affected zone spanning the first channel together constitute a hydrophilic pattern of the split annular array structure.

[0008] Step 3: The prepared solution for crystal growth by solution method is coated on the substrate. The solution selectively wets the substrate and is directionally deposited on the hydrophilic pattern of the split ring array structure to form a crystal film.

[0009] Step 4: Use a pulsed laser to perform a second etching on each split ring in the split ring array structure, thereby forming a double electrode with mutual insulation between the inside and outside of the split ring pattern, and the spacing between the double electrodes is the width of the first channel.

[0010] Furthermore, before forming the hydrophobic layer, the process further includes forming hydrophilic groups on the conductive layer.

[0011] Furthermore, the substrate includes: glass, silicon wafer, and flexible polymer.

[0012] Furthermore, the conductive layer includes: an ITO layer, an oxide plating layer (e.g., an FTO plating layer), an MXene plating layer, and metal plating layers such as Au, Ag, Cu, Pt, and Al.

[0013] Furthermore, step 4, using a pulsed laser to perform a second etching on each split ring in the split ring array structure, includes: using a pulsed laser to etch the hydrophobic layer and conductive layer at the gaps of each split ring in the split ring array structure to form a second channel. This second channel fills the gaps in the split ring pattern, thereby forming a dual electrode that is mutually insulated inside and outside the split ring pattern. By sealing the gaps in the split rings, the internal and external electrodes of the split ring pattern are formed, allowing a microprobe to be used to contact the electrodes and connect them to an external power source.

[0014] Alternatively, step 4, using a pulsed laser to perform a second etching on each split ring in the split ring array structure, includes: using a pulsed laser to etch the hydrophobic layer and the conductive layer in the regions on both sides of the notch of each split ring in the split ring array structure to form a third channel and a fourth channel. The third channel and the fourth channel are respectively connected to the first channel and extend appropriately, thereby forming a dual electrode that is mutually insulated inside and outside the split ring pattern. For example, the third channel and the fourth channel are respectively connected to the first channel and extend to the edge of the substrate, which is equivalent to extending the notch position of the split ring to the edge of the substrate. In this case, a clamp can be used to contact the electrode and connect it to an external power supply.

[0015] Furthermore, the width of the heat-affected zone is greater than the width of the first channel.

[0016] Furthermore, the structure of the split annular first channel includes annular patterns such as circular rings, triangular rings, and quadrilateral rings, with dimensions between 5μm and 500μm and ring widths between 1 and 50μm. The annular patterns have gaps, with the minimum size of the gap being 1μm and the maximum being the side length of a polygonal ring or the diameter of a circular ring.

[0017] Furthermore, the solution in which the crystal can be grown by solution method includes a perovskite precursor solution, and the crystal film is a perovskite crystal film.

[0018] Furthermore, the dual-electrode device includes a photodetector, and the perovskite crystal film is the photoelectric material layer of the photodetector.

[0019] Furthermore, the pulsed laser includes nanosecond pulsed lasers, picosecond pulsed lasers, and femtosecond pulsed lasers with wavelengths of ultraviolet, green, blue, and infrared.

[0020] The embodiments of the present invention have the following beneficial effects:

[0021] (1) This invention provides a method for fabricating a transverse dual-electrode device array based on laser etching. It cleverly utilizes the cumulative photothermal effect generated during the etching process of a pulsed laser, combining the characteristic that the heat-affected zone (HAZ) is larger than the etched area with the surface tension-limited droplet array technology. An insulating channel is formed by etching the conductive layer with a pulsed laser. Simultaneously, the photothermal effect generated near the pulsed laser beam destroys the hydrophobic layer on both sides of the channel, thereby reducing its hydrophobic effect and forming the HAZ. When a solution capable of growing crystals using a solution method is coated onto the substrate, the presence of the HAZ ensures that the solution can wet and completely cover the laser-etched channel. Finally, the deposited crystalline film can laterally span both sides of the channel, forming a transverse dual-electrode device.

[0022] (2) The method for fabricating a transverse structure dual electrode device array based on laser etching according to the present invention can simultaneously perform hydrophilic and hydrophobic liquid patterning modification and electrode patterning treatment on the substrate surface, which greatly reduces production costs and process steps, solves the problems of accuracy deviation and damage and consumption of active materials in the two patterning processes, and provides a new idea for fabricating transverse structure dual electrode devices.

[0023] (3) In the preparation of crystal film arrays, the dewetting process of the solution (precursor fluid) on the substrate surface is enhanced by using split ring pattern, thereby assisting the directional transport of microdroplets on specific structures, and then achieving the deposition of high-density crystal film arrays through evaporation crystallization and other methods.

[0024] (4) The transverse structure dual electrode device prepared by the method of preparing a transverse structure dual electrode device array based on laser etching according to the present invention has a spacing between the two electrodes that is only the width of the laser etching channel, which enables the dual electrode device to transfer and transmit charges inside and outside the split ring pattern. This greatly shortens the current transmission distance on the active material, thereby fully utilizing the utilization rate of the active material layer (crystal film), improving the photoelectric conversion efficiency, effectively saving the minimum area of ​​the array device unit, and facilitating device miniaturization.

[0025] (5) The method for fabricating a lateral structure dual electrode device array based on laser etching according to the present invention greatly reduces the process steps and costs compared with traditional patterning methods such as photolithography and mask evaporation. Moreover, the process does not require masking, stripping, molding, or transfer processes, and can realize the fabrication of large-area, high-throughput, arrayed lateral structure dual electrode devices. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This is a schematic diagram of the hydrophobic treatment of the conductive substrate surface according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the laser etching mechanism applied to the substrate surface according to an embodiment of the present invention;

[0029] Figure 3 Microscopic images showing the etching effect of nanosecond ultraviolet pulsed lasers of different powers on POTS hydrophobic ITO conductive glass substrates according to embodiments of the present invention.

[0030] Figure 4 The images show SEM images of the substrate cross-section and surface profile measurement curves after perovskite film deposition according to embodiments of the present invention.

[0031] Figure 5 Elemental characterization and composition analysis curves of the perovskite photodetector according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the device structure and a schematic diagram of the photoconductive detector based on perovskite crystal film according to an embodiment of the present invention.

[0033] Figure 7 Microscopic images and transmission spectral analysis curves of the perovskite crystal film array according to embodiments of the present invention;

[0034] Figure 8The photoelectric performance of the perovskite photodetector according to the embodiments of the present invention is characterized. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of the present invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0036] This invention provides a method for fabricating a lateral dual-electrode device array based on laser etching. It cleverly utilizes the cumulative photothermal effect generated during the etching process of pulsed laser beams (including nanosecond, picosecond, and femtosecond lasers), combining the characteristic that the heat-affected zone is larger than the etched area with the surface tension-limited droplet array technology. Electrode patterning is simultaneously performed during the hydrophilic / hydrophobic liquid patterning modification of the substrate surface, significantly reducing production costs and process steps, and providing a new approach for fabricating lateral dual-electrode devices. The following example of fabricating a lateral photoconductive photodetector will be used to specifically illustrate the concept of this invention.

[0037] A method for fabricating a lateral dual-electrode device array based on laser etching includes the following steps:

[0038] Step 1: Provide a substrate with a conductive layer, and form a hydrophobic layer on the conductive layer.

[0039] The substrate includes glass, silicon wafers, and flexible polymers. The conductive layer on the substrate can include ITO (Sn-doped In₂O) coatings, oxide coatings (e.g., FTO (F-doped SnO₂) coatings), and MXene (MXenes are a class of two-dimensional inorganic compounds in materials science. These materials consist of transition metal carbides, nitrides, or carbonitrides with a thickness of several atomic layers. MXenes are graphene-like structures obtained by processing MAX phases. The specific molecular formula of the MAX phase is M...). n+1 AX n(n = 1, 2 or 3), where M refers to transition metals from the first few groups, A refers to main group elements, and X refers to C and / or N elements. Since MX has strong bond energies and A has high chemical reactivity, A can be removed from the MAX phase through etching, thus obtaining a graphene-like 2D structure—MXene. Coatings and metal coatings such as Au, Ag, Cu, Pt, and Al are also used. In this embodiment, a perovskite photoconductive photodetector is fabricated on ITO conductive glass. Specifically, the ITO conductive glass is rinsed with acetone and ethanol to dissolve most of the organic matter, then cleaned with deionized water to remove residual ions. After drying with nitrogen, the substrate surface is bombarded with a plasma cleaner to generate hydrophilic groups, which increases the wetting effect of the hydrophobic material on the substrate surface. Figure 1 This is a schematic diagram of the hydrophobic treatment of the conductive substrate surface according to an embodiment of the present invention. Figure 1 As shown in Figure a, a uniformly distributed POTS liquid-repellent layer is formed by vapor deposition of fluorosilane (1H,1H,2H,2H-perfluorooctyltriethoxysilane, POTS) or other liquid-repellent solutions onto the surface of a conductive substrate. Figure 1 As shown in b, the surface of the conductive substrate after hydrophobic modification has a static contact angle of about 80° with the 0.4 mol / L CsPbBr3 perovskite precursor solution in dimethyl sulfoxide (DMSO) solvent, exhibiting a hydrophobic effect.

[0040] Step 2: Use a pulsed laser to etch the substrate, where the energy of the center of the pulsed laser spot is used to etch the hydrophobic layer and the conductive layer to form a split annular first channel array. The photothermal effect of the pulsed laser is used to destroy the hydrophobic layer on both sides of the first channel to form a heat-affected zone. The first channel and the heat-affected zone spanning the first channel together constitute the hydrophilic pattern of the split annular array structure.

[0041] Figure 2 This is a schematic diagram illustrating the laser etching mechanism applied to the substrate surface according to an embodiment of the present invention. Figure 2As shown, the YZ plane reveals a typical Gaussian distribution of laser beam intensity (note: the Z-axis points downwards, indicating increasing energy), while the XY plane presents a three-dimensional view of the laser's effect on the conductive glass substrate surface. The specific process is as follows: when the Gaussian laser beam strikes the substrate surface, the high energy at the center of the beam is sufficient to vaporize the ITO conductive layer, forming an etched area. Simultaneously, because the vaporization temperature of the POTS layer is much lower than that of ITO, the molecular chains of POTS are affected by the photothermal effect generated near the beam, resulting in damage and reduced hydrophobicity, forming a heat-affected zone (HAZ) of a certain lateral width. It is noteworthy that the width of the HAZ is always significantly larger than the etched area (i.e., the split annular first channel). This phenomenon ensures that the area wettable by the active material (perovskite) precursor solution completely covers the ITO channels generated after laser etching. Finally, after an evaporation and crystallization process, the photoelectric active material can laterally span both sides of the ITO channels, forming a lateral dual-electrode device.

[0042] Specifically, a hydrophilic pattern with a split ring array structure of different wettability is prepared on the surface of a hydrophobic substrate by nanosecond laser etching. The auxiliary droplet unit achieves dewetting inside the split ring pattern, thereby realizing the directional transport of the perovskite precursor solution. The specific process is as follows: Under the action of a horizontal external force along the notch direction of the split ring pattern unit, the advancing CsPbBr3 precursor solution continuously wets and dewets on the substrate until the retreating three-phase contact line (TCL) contacts the pattern boundary of the split ring unit and is pinned by the hydrophilic pattern to form a liquid bridge. The liquid bridge gradually thins and narrows under the continuous pull of the horizontal external force until it ruptures instantaneously, forming droplets within each split ring unit, thus generating a discontinuous first dewetting process. When the liquid bridge ruptures, the TCL contracts along the outer boundary of the hydrophilic pattern and contacts the hydrophobic split ring notch. Due to the imbalance between the pinning force and surface tension, the liquid film of the droplets within each split ring unit is in a metastable state. Therefore, the TCL of the liquid film continuously shrinks back to the hydrophobic region of the split ring pattern, eventually forming split ring-shaped perovskite precursor droplets within each split ring unit, which is the second dewetting process. Through these two dewetting processes, directional transport of the solution is achieved, ultimately forming a high-precision array of split ring-shaped perovskite precursor droplets. The outline and gaps of the split ring pattern determine whether the first and second dewetting processes can occur. In this embodiment, the structure of the split ring includes annular patterns such as circular rings, triangular rings, and quadrilateral rings, with dimensions between 5μm and 500μm and ring widths between 1 and 50μm. The annular patterns have gaps, with the smallest gap size being 1μm and the largest being the side length of a polygonal ring or the diameter of a circular ring.

[0043] The pulsed lasers used include nanosecond pulsed lasers, picosecond pulsed lasers, and femtosecond pulsed lasers with wavelengths of ultraviolet, green, blue, and infrared. Figure 3These are microscopic images showing the etching effect of nanosecond ultraviolet pulsed lasers of different powers on a POTS-treated hydrophobic ITO conductive glass substrate, according to embodiments of the present invention. Figure 3 As shown, with the increase of laser power, the energy and thermal effect at the laser spot also increase. Lasers with too low power, due to their low center temperature, are insufficient to completely vaporize the ITO conductive layer, resulting in phenomena such as… Figure 3 (b) The non-uniform breakpoints shown on the left will cause leakage current between the ITO dual electrodes, resulting in photodetector malfunction or short circuit; excessively powerful lasers can damage the glass substrate, increasing the surface roughness of the substrate and affecting the contact between the perovskite film and the substrate. Furthermore, high-power etching easily forms a hot-melt zone in the substrate material or its oxides. The surface undulations of this molten zone will affect the deposition effect of the perovskite film. The corresponding SEM (scanning electron microscope) images are shown below. Figure 3 (b) As shown on the right. Therefore, etching is performed using a 55mW nanosecond pulsed laser, as... Figure 3 As shown in (b), appropriate power can effectively etch the ITO conductive layer and also etch the relatively wide POTS hydrophobic layer through thermal effects, which is beneficial to the subsequent perovskite film deposition process. Besides nanosecond lasers, higher frequency pulsed lasers such as picosecond and femtosecond lasers often offer higher processing accuracy due to their smaller thermal effects. In this invention, thermal effect is a necessary condition for simultaneously achieving hydrophobic and hydrophobic patterning modification and electrode patterning. Therefore, by adjusting laser processing parameters such as increasing the number of etching passes, increasing laser power, and decreasing scanning speed, an effective balance between processing accuracy and thermal effect can be achieved through process optimization.

[0044] Step 3: The prepared solution for crystal growth by solution method is coated on the substrate. The solution selectively wets the substrate and is oriented to deposit on the hydrophilic pattern of the split ring array structure to form a crystal film.

[0045] Crystalline materials can be grown from solid, liquid, and gas phases. Among liquid-phase growth methods, solution methods are widely used due to their mild reaction conditions, high efficiency, low processing cost, and suitability for large-area fabrication. After laser etching, ITO etching channels and a POTS heat-affected zone spanning both sides of the channels are formed on the substrate surface. This heat-affected zone, bombarded by a high-energy laser beam, develops strong hydrophilic properties, becoming a site that can be selectively wetted by the perovskite precursor solution. This solution can then undergo an evaporation-induced self-assembly process to form a perovskite polycrystalline thin film, which becomes a photoactive material for photodetectors. Figure 4 These are SEM images of the substrate cross-section and surface profile measurement curves after perovskite film deposition according to an embodiment of the present invention. The SEM images of the sample cross-section after perovskite film deposition are shown below. Figure 4As shown in (a), the perovskite film exhibits low porosity, demonstrating good crystal quality. Furthermore, the good interfacial contact between the perovskite, ITO, and glass ensures the collection and transmission of photocurrent. Figure 4 (b) shows the height variation of the sample interface profile. As shown in the figure, the channel depth generated after etching the ITO conductive layer is 180 nm, which is consistent with the thickness of the ITO coating, indicating that the ITO in the channel has been completely etched; the surface height after perovskite deposition is about 600 nm, and it completely covers both sides of the ITO electrode channel, forming good contact.

[0046] Figure 5 Elemental characterization and compositional analysis of the perovskite photodetector according to embodiments of the present invention are shown below. SEM images and elemental mapping spectra of the ITO conductive substrate after etching and after deposition of the perovskite film are as follows. Figure 5 As shown in (a), the elemental distribution indicates that the main components of the ITO channel formed after etching are Si and O, while the main components outside the etching lines are In and Sn. This suggests that the etched area has completely vaporized the ITO conductive layer, forming an exposed glass substrate. The deposited perovskite polycrystalline film is uniformly distributed with Cs, Pb, and Br, and the deposition width of the perovskite film can completely cover both sides of the ITO channel. Phase analysis of the CsPbBr3 film annealed at 80℃ was performed by X-ray diffraction, and its diffraction pattern is shown below. Figure 5 As shown in (b), the CsPbBr3 film exhibits distinct double diffraction peaks at 15° and 30°, corresponding to the (001) and (-100) and (002) and (-200) crystal planes, respectively, which correspond well to the characteristic peaks of the PDF#18-0364 card. Furthermore, the cubic crystal orientation characteristic peak of In2O3 is clearly observed at 35.466°, corresponding to the PDF#06-0416 card, indicating that no new impurities were introduced during the entire preparation process.

[0047] Step 4: Use a pulsed laser to perform a second etching on each split ring in the split ring array structure, thereby forming a double electrode that is mutually insulated inside and outside the split ring pattern, with the spacing between the double electrodes being the width of the first channel.

[0048] This step involves etching the external circuitry. Figure 6 This is a schematic diagram of the device structure and photoelectric sensing mechanism of a perovskite film-based photoconductive detector according to an embodiment of the present invention. Figure 6As shown in (a), the split-ring perovskite crystal array is etched again using laser etching technology to create the external circuit. The ITO channels generated by the two etching processes are connected and appropriately extended to facilitate the connection of wires or probes, thus forming two independent ITO electrodes inside and outside the split-ring pattern. Specifically, a pulsed laser is used to etch the hydrophobic and conductive layers at the gaps of each split ring in the split-ring array structure to form a second channel. The second channel fills the gaps in the split-ring pattern, thereby forming a dual electrode that is insulated from the inside and outside of the split-ring pattern. This is equivalent to forming a minimum extension, sealing the gaps in the split rings, so that the inside and outside of the split-ring pattern form mutually isolated electrodes. At this time, a microprobe can be used to contact the electrodes and connect them to an external power supply. Alternatively, a pulsed laser is used to etch the hydrophobic and conductive layers in the regions on both sides of the gaps in each split ring in the split-ring array structure to form a third and fourth channel. The third and fourth channels are connected to the first channel and appropriately extended, thereby forming a dual electrode that is insulated from the inside and outside of the split-ring pattern. This situation is equivalent to forming maximum extension; for example, the third and fourth channels connect to the first channel and extend to the substrate edge, essentially extending the notch of the split ring to the substrate edge. At this point, a clamp can be used to contact the electrodes and connect them to an external power supply. When the device receives light, the photocurrent is laterally conducted and collected by the two bias electrodes inside and outside the device. An optical micrograph of the split-ring structured perovskite photodetector is shown below. Figure 6 As shown in (b), the ITO channels covering the perovskite polycrystalline thin film are the first channel array generated by the first laser etching, and the ITO channels near the split ring notch are generated by the second laser etching. The two etched areas overlap, which can ensure the mutual insulation between the internal and external circuits of the split ring pattern. Figure 6 Images (c)-(d) show magnified views of the perovskite photodetector and schematic diagrams of its photoelectric response mechanism. The photoconduction is essentially that of a transversely structured photoconductive detector. Under illumination, the CsPbBr3 crystal generates electron-hole pairs, which are collected by the ITO electrodes at both ends under an applied bias voltage, forming a photocurrent. The electrode spacing produced by this fabrication method is only the width of the channel etched in the first laser etching, which greatly shortens the current transmission distance on the active material and fully utilizes the perovskite photoactive layer. Furthermore, the highly transparent glass substrate allows the detector to perform light detection on both sides of the substrate, expanding the application range and flexibility of the device.

[0049] Figure 7 Microscopic images and transmission spectral analysis curves of the perovskite crystal film array according to embodiments of the present invention. Figure 7(a) The letters “SHU” shown in the photograph consist of a split-ring structured perovskite thin film array. The inset on the right is a magnified SEM image of a portion of the array. The perovskite unit has a size of 200 μm. 2 At this array density, 1cm 2 The substrate surface can accommodate 900 perovskite crystal units while maintaining good density and uniformity. Figure 7 (b) shows the transmittance curve of the sample. The transmittance in the visible light band is >80%, and its excellent optical transparency allows it to be integrated into surfaces such as automotive glass and displays without obstructing the transmission of background image information, expanding the application areas of transparent sensors. For arrayed devices, the limiting factor for the minimum area of ​​the device unit is not only the relative size of the active material pattern, but also the connection issues of electrodes, probes, and wires. The embodiments of this invention use an active material with a split-ring structure, enabling charge transfer and transport between the inside and outside of the split-ring pattern in a dual-electrode device. The inside and outside of the split-ring pattern cleverly form two independent electrodes, and the distance between the two electrodes is the width of the laser etching channel. This not only greatly reduces the current transmission distance and improves the utilization rate of the perovskite photoactive layer, but also effectively saves the minimum area of ​​the arrayed device unit.

[0050] Smaller electrode spacing provides a faster path for carrier transport, which is more conducive to the separation and collection of photogenerated carriers. Figure 8 The photoelectric performance of the perovskite photodetector according to the embodiments of the present invention is characterized. Figure 8 (a) shows the IV curves of this photoconductive detector under illumination of a 10mW light source with a wavelength of 520nm and in darkness. The maximum on / off ratio of this device was measured to be 8.2 × 10⁻⁶ at 2.3V. 3 It also has a low dark current of 2.03 × 10⁻⁶. -11 A. For example Figure 8 (b) shows the photocurrent variation curves of the photodetector under five cycles of 450nm pulsed light with a bias voltage of 1V-6V. Since the photogenerated carriers generated by the light will drift under the bias voltage, and the drift velocity of the carriers is proportional to the magnitude of the photocurrent, the photocurrent value of the device increases with the increase of the applied bias voltage. Response speed refers to the relaxation time of the detector in converting the incident light signal into a current signal. It is usually defined as the rise time T of the detector, which is the time required for the photocurrent value to rise from 10% to 90% and then fall from 90% to 10%. rise and descent time T down The response time curve of the device under illumination is as follows: Figure 8 As shown in (c), the detector's light response rise time is 14.6 ms and fall time is 29.8 ms, which is close to the recognition speed of the human eye.

[0051] The method for fabricating a lateral dual-electrode device array based on laser etching according to embodiments of the present invention utilizes the thermal effect of the laser beam to simultaneously complete the substrate hydrophilic / hydrophobic liquid patterning and electrode patterning processes in a single etching process. By employing surface tension-limited droplet array technology, the solution is selectively retained at the electrode etching site for evaporation and crystallization, thereby obtaining a lateral dual-electrode device array. The fabrication method according to embodiments of the present invention eliminates the need for separate arraying of active materials and electrode materials; it achieves the process through a single patterning process using laser etching. This solves the problems of precision deviation and damage and consumption of active materials caused by two patterning processes, enabling the fabrication of large-area, high-throughput, arrayed lateral dual-electrode devices.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for fabricating a transverse dual-electrode device array based on laser etching, characterized in that, include: Step 1: Provide a substrate with a conductive layer, and form a hydrophobic layer on the conductive layer; Step 2: The substrate is etched using a pulsed laser, wherein the energy of the center of the pulsed laser spot is used to etch the hydrophobic layer and the conductive layer to form a split annular first channel array, and the photothermal effect of the pulsed laser is used to destroy the hydrophobic layer on both sides of the first channel to form a heat-affected zone. The first channel and the heat-affected zone spanning the first channel together constitute a hydrophilic pattern of the split annular array structure. Step 3: The prepared solution for crystal growth by solution method is coated on the substrate. The solution selectively wets the substrate and is directionally deposited on the hydrophilic pattern of the split ring array structure to form a crystal film. Step 4: Use a pulsed laser to perform a second etching on each split ring in the split ring array structure, thereby forming a double electrode with mutual insulation between the inside and outside of the split ring pattern, and the spacing between the double electrodes is the width of the first channel.

2. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 1, characterized in that, Before forming the hydrophobic layer, the process further includes forming hydrophilic groups on the conductive layer.

3. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 1, characterized in that, The substrate includes: glass, silicon wafer, and flexible polymer; The conductive layer includes: an ITO layer, an oxide coating, an MXene coating, and metal coatings of Au, Ag, Cu, Pt, and Al.

4. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 1, characterized in that, Step 4 involves using a pulsed laser to perform a second etching on each split ring in the split ring array structure, including: The hydrophobic layer and conductive layer at the gaps of each split ring in the split ring array structure are etched using a pulsed laser to form a second channel. The second channel fills the gaps in the split ring pattern, thereby forming a dual electrode that is mutually insulated inside and outside the split ring pattern.

5. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 1, characterized in that, Step 4 involves using a pulsed laser to perform a second etching on each split ring in the split ring array structure, including: Using a pulsed laser, the hydrophobic layer and the conductive layer are etched on both sides of the notch of each split ring in the split ring array structure to form a third channel and a fourth channel. The third channel and the fourth channel are respectively connected to and extend from the first channel, thereby forming a dual electrode that is mutually insulated inside and outside the split ring pattern.

6. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 1, characterized in that, The width of the heat-affected zone is greater than the width of the first channel.

7. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 1, characterized in that, The structure of the split annular first channel includes annular patterns such as circular rings, triangular rings, and quadrilateral rings, with dimensions between 5μm and 500μm and ring widths between 1 and 50μm. The annular patterns have gaps, with the minimum size of the gap being 1μm and the maximum being the side length of a polygonal ring or the diameter of a circular ring.

8. The method for fabricating a lateral dual-electrode device array based on laser etching according to any one of claims 1-6, characterized in that, The solution from which crystals can be grown by solution method includes a perovskite precursor solution, and the crystal film is a perovskite crystal film.

9. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 8, characterized in that, The dual-electrode device includes a photodetector, and the perovskite crystal film is the photoelectric material layer of the photodetector.

10. The method for fabricating a lateral dual-electrode device array based on laser etching according to claim 8, characterized in that, The pulsed lasers include nanosecond pulsed lasers, picosecond pulsed lasers, and femtosecond pulsed lasers with wavelengths of ultraviolet, green, blue, and infrared.

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