Laser processing system based on spatial light modulator

Abstract

The utility model provides a laser processing system based on a spatial light modulator. The laser processing system comprises a laser, a beam expander, the spatial light modulator, two convex lenses, a reflector, a focusing objective lens, a mobile platform and a distance measuring device. The perovskite solar cell laser processing system can effectively improve the precision and speed of laser processing. Dynamic adjustment of laser beams is achieved through the spatial light modulator, and accurate control over the light spot form and the focus position in the machining process is ensured.

Description

Technical Field

[0001] This utility model relates to a laser processing equipment, and more particularly to a laser processing system for perovskite solar cells based on a spatial light modulator, which is suitable for laser scribing processing of perovskite solar cells. Background Technology

[0002] Perovskite solar cells, as a novel photovoltaic material, offer lower production costs and higher photoelectric conversion efficiency compared to traditional silicon-based solar cells. The manufacturing process of perovskite photovoltaic cells involves multiple layers of deposition and processing, with laser processing being a crucial step. The precision of laser scribing directly impacts the performance and yield of the solar cells.

[0003] Current laser scribing technology typically relies on mechanical scanning and fixed optical components to move and adjust the laser beam. While this method can meet basic processing requirements, it has limitations in terms of processing speed, accuracy, and flexibility. With the increasing size of perovskite solar cells and the rising demands for processing precision, traditional laser processing methods struggle to meet the demands for high efficiency, precision, and flexibility. Therefore, improving the dynamic adjustment capability of laser processing systems, shortening processing time, and achieving seamless switching between different process steps have become key challenges in the production of perovskite solar cells. Utility Model Content

[0004] To address the problems in existing technologies, this utility model provides a laser processing system based on a spatial light modulator, comprising a laser, a beam expander, a spatial light modulator, two convex lenses, a reflector, a focusing objective lens, a moving platform, and a ranging device. The laser generates a laser beam; the beam expander collimates the laser beam and adjusts the beam's spot size, enabling dynamic adjustment of the laser beam to meet the requirements of subsequent optical components; the spatial light modulator adjusts the spatial distribution of the laser beam by regulating its phase and amplitude; the two convex lenses form a 4F optical system, which is used to adjust the laser beam size for focusing. Numerical aperture matching of the objective lens; the first convex lens: its focal length is equal to the distance from the spatial light modulator to the convex lens; the second convex lens: the optical path distance between the second and first convex lenses is equal to the sum of the focal lengths of the two convex lenses; the reflecting mirror changes the transmission direction of the laser beam, making the beam vertically downward, and finally focused onto the surface of the object to be processed by the focusing objective lens; the focusing objective lens focuses the adjusted laser beam onto the surface to be processed for processing; the moving platform is used to fix the object to be processed and supports precise movement along the x and y directions under computer control; the ranging device is used to measure the height of the object to be processed to ensure that the laser focus remains consistent on the surface of the object to be processed at different heights.

[0005] As a further improvement of this utility model, the laser is a continuous laser, nanosecond laser, picosecond laser or femtosecond laser, with a wavelength range from 450nm to 1550nm.

[0006] As a further improvement of this utility model, the spatial light modulator adjusts the shape, phase and focal position of the laser beam, and adjusts the number of beam splits and the beam spacing by loading a hologram. The spatial light modulator splits a beam of light into multiple sub-beams, and enables multiple parallel beams to perform laser processing on the surface of the object to be processed simultaneously.

[0007] As a further improvement of this utility model, the distance from the first convex lens to the reflecting mirror is not equal to the focal length of the first convex lens.

[0008] As a further improvement of this utility model, the ranging device measures the height of the surface of the object to be processed in real time, and the computer adjusts the position of the laser focus according to the height change.

[0009] The beneficial effects of this invention are as follows: This invention provides a laser processing system based on a spatial light modulator. This system achieves functions such as laser beam shape adjustment, laser beam splitting, and focus adjustment through the spatial light modulator. By dynamically adjusting the shape, distribution, and focus of the laser beam, this system achieves precise scribing, for example, precise scribing of perovskite solar cells. This system not only improves the accuracy of laser processing but also allows for flexible adjustment of processing parameters according to different processing requirements, significantly improving production efficiency.

[0010] Laser Beam Adjustment and Splitting: The spatial light modulator, as a core component, enables efficient adjustment of the laser beam. Through computer control, the beam's shape and intensity distribution are adjusted after passing through a beam expander and spatial light modulator. Furthermore, laser beam splitting can be achieved by loading different holograms. The system can split a single laser beam into multiple beams according to production needs, forming multiple parallel focused spots, enabling simultaneous multi-point processing and significantly improving production efficiency.

[0011] Focus adjustment and compensation function: The spatial light modulator can not only control the shape of the laser beam but also precisely adjust the focus depth. Combined with a ranging device, the system can monitor the height of the battery surface in real time and dynamically adjust the laser focus to ensure accurate processing at different surface heights. This function effectively avoids processing accuracy problems caused by uneven battery surfaces.

[0012] By using a spatial light modulator (SLM), this system can precisely control the shape, beam splitting, and focal depth of the laser, thereby achieving high-precision laser scribing of each layer of perovskite solar cells. The system and method of this invention are highly adaptable, capable of adjusting laser parameters in different processing steps, enabling parallel processing of multiple laser spots, and significantly improving production efficiency. Attached Figure Description

[0013] Figure 1 A schematic diagram of the laser process for producing S-type tandem perovskite photovoltaic cells, showing laser scribing steps such as P1, P2, and P3;

[0014] Figure 2 The schematic diagram of the laser processing system of this utility model includes components such as a laser, a spatial light modulator, optical elements, and a ranging device.

[0015] The components in the diagram are named as follows: laser 100, beam expander 200, spatial light modulator 300, convex lens 400, reflector 500, focusing objective lens 600, moving platform 700, and ranging device 800. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] A laser processing system based on a spatial light modulator is described, taking a perovskite solar cell laser processing system based on a spatial light modulator as an example.

[0018] This invention relates to a laser processing system comprising a laser, a beam expander, a spatial light modulator, two convex lenses, a reflector, a focusing objective, a moving platform, and a ranging device. The system is compact in structure and precise in control, capable of adjusting the laser beam shape, focal point position, and number of beams as needed to adapt to different process requirements.

[0019] The structure of the laser processing system of this utility model is as follows: Figure 2 As shown, it mainly includes the following parts:

[0020] Laser 100: Used to generate high-quality laser beams. The laser can be a continuous laser, nanosecond laser, picosecond laser, or femtosecond laser, with a wavelength range from 450nm to 1550nm. A suitable laser can be selected according to actual processing requirements. Laser 100 provides different laser beams by adjusting parameters such as laser power and frequency.

[0021] Beam expander 200: Used to collimate the laser beam and adjust the beam spot size. The beam expander enables dynamic adjustment of the laser beam to meet the requirements of subsequent optical components.

[0022] Spatial Light Modulator 300: Employing a liquid crystal spatial light modulator (SLM), this device precisely adjusts the spatial distribution of the laser beam by regulating its phase and amplitude. The SLM can adjust the beam shape and intensity in real time at each laser processing step, controlling the laser's focal position and spot shape. By loading different holograms, the SLM can convert a Gaussian beam into a flat-top beam and independently adjust each spot, ensuring that the spot shape and depth of focus meet the required specifications.

[0023] Convex Lens 400: Two convex lenses 400 form a 4F optical system, which is used to adjust the laser beam size to match the numerical aperture of the focusing objective. The 4F optical system is a commonly used optical system consisting of two lenses used to adjust the laser beam size to match the numerical aperture of the focusing objective 600. Specifically: First convex lens: Its focal length is equal to the distance from the spatial light modulator 300 to this convex lens, serving as a preliminary beam adjustment. Second convex lens: The optical path distance (the distance traveled by the light path, not a straight line distance) between this convex lens and the first convex lens is equal to the sum of the focal lengths of the two convex lenses, and the distance from the first convex lens to the reflecting mirror 500 cannot be equal to the focal length of the first convex lens, in order to avoid focusing on the reflecting mirror 500. It is used for further adjustment of the beam size and shape.

[0024] Reflector 500: Used to change the transmission direction of the laser beam so that the beam is vertically downward and finally focused onto the surface of the object to be processed, such as the surface of a perovskite solar cell, by the focusing objective lens 600.

[0025] Focusing objective 600: Focuses the adjusted laser beam onto the surface of the perovskite solar cell for processing, ensuring the accuracy of the focal point and the clarity of the light spot, and completing the precise etching of the TCO layer, electron transport layer, perovskite layer, etc.

[0026] TCO: Conductive glass, also known as transparent conductive oxide glass, is a material on which a thin film of transparent conductive oxide is deposited on the surface of glass by physical or chemical methods.

[0027] Mobile platform 700: Used to fix objects to be processed, such as perovskite solar cells, and supports precise movement along the x and y directions under computer control. The platform can perform precise positioning during laser scribing, ensuring that the position of each laser spot is consistent with the path.

[0028] Ranging device 800: Used to measure the height of perovskite solar cells, ensuring that the laser focus remains consistent on the surface of perovskite solar cells at different heights, thereby avoiding processing errors caused by changes in laser focal length.

[0029] This system, through the collaboration of components such as a laser, beam expander, spatial light modulator, convex lens, reflector, ranging device, and moving platform, can precisely adjust the shape, focal depth, and number of beams of the laser beam, enabling parallel processing of multiple light spots. The spatial light modulator dynamically adjusts the phase, intensity, and focal position of the laser beam, allowing the system to not only precisely process perovskite solar cell surfaces at different heights but also customize the number and spacing of light spots according to requirements. This technical solution effectively improves the laser processing efficiency and precision of perovskite solar cells, making it suitable for large-scale, high-efficiency photovoltaic cell production lines.

[0030] The laser scribing method of this invention achieves precise processing of perovskite photovoltaic cells through the following steps. In this embodiment, the production process of perovskite solar cells is completed using a laser processing system.

[0031] 1. Step P1 (Laser Scribing of TCO Substrate): In step P1, the height of the perovskite solar cell is first measured using a ranging device 800. Based on the preset number of beam splitters and beam spacing, a hologram for step P1 is generated by computer calculation. The hologram is loaded onto the spatial light modulator 300, adjusting the shape and focus of the laser beam. The computer controls the laser 100 to output laser light and controls the moving platform 700 to perform precise movement in the x and y directions, completing the laser scribing of the P1 layer. The goal of the P1 layer is to etch the TCO substrate, forming independent TCO blocks.

[0032] 2. Step P2 (Laser scribing of the electron transport layer, perovskite layer, and hole transport layer): Step P2 also uses the ranging device 800 to measure the surface height of the battery and generate a hologram for step P2. The distribution and focus of the laser beam are controlled by the spatial light modulator 300, and the computer controls the laser and platform to complete the laser scribing of the electron transport layer, perovskite layer, and hole transport layer. In this step, the laser only etches the upper layers, exposing the TCO layer.

[0033] 3. P3 Step (Laser Scribing of Back Electrode, Electron Transport Layer, and Perovskite Layer): In the P3 step, a ranging device is used to measure the surface height of the cell and generate a hologram for the P3 step, which is then loaded onto the spatial light modulator 300. Through precise laser control, laser scribing is performed on the back electrode, electron transport layer, and perovskite layer, separating the sub-cells.

[0034] 4. Beam Shape Adjustment and Compensation: In each of the above steps, the spatial light modulator 300 adjusts the phase and amplitude of the laser beam to achieve beam shaping. For example, it can transform a Gaussian spot into a flat-topped spot, ensuring that the spot shape is uniform and the focus is precise during laser scribing. Furthermore, the spatial light modulator can compensate for focus shifts caused by differences in the surface height of the perovskite solar cell, ensuring that the focal position of each spot remains consistent.

[0035] First, the surface height of the perovskite solar cell is measured in real time using a ranging device. A hologram for step P1 is generated under computer control and loaded into a spatial light modulator, adjusting the shape, focal point, and number of beams of the laser beam. After passing through a beam expander and the spatial light modulator, the beam is adjusted to a suitable shape for processing, then focused by a 4F optical system, and finally illuminates the TCO substrate of the perovskite solar cell, achieving laser scribing in step P1. Through this step, the TCO layer is etched into several independent regions, providing positioning for subsequent steps P2 and P3.

[0036] Steps P2 and P3 are executed similarly to step P1, except that the laser beam shape, focal depth, and number of beams are adjusted according to the needs of different layers. The system dynamically adjusts the laser focus by measuring the height of the battery surface in real time, ensuring that the laser scribing process for each layer can be completed accurately.

[0037] The laser processing method of this invention, through the adjustment of a computer control system, can complete laser scribing of TCO layers, electron transport layers, perovskite layers, and hole transport layers, thus meeting the precision manufacturing requirements of perovskite solar cells.

[0038] Functional integration of spatial light modulator 300

[0039] (1) Beam splitting function: The spatial light modulator 300 decomposes the incident beam into multiple sub-beams by loading a hologram, thereby realizing the parallel processing of multiple light spots.

[0040] Principle: Holograms split a beam of light into a specified number of beams through phase modulation, forming a regularly arranged array of light spots, such as linear arrays or rectangular arrays.

[0041] Features: The number and spacing of light spots can be adjusted in real time according to the design of the hologram, resulting in high beam splitting efficiency and uniform beam energy distribution.

[0042] Application: In steps P1, P2, and P3, the beam splitting function can complete multiple scribing lines at once, significantly improving processing efficiency.

[0043] (2) Beam shaping function: Gaussian distributed beams can cause uneven processing. Spatial light modulators can shape them into flat-top beams so that the beam energy is evenly distributed on the processing surface.

[0044] Principle: By adjusting the phase distribution of light waves through holographic design, the Gaussian beam is converted into a flat-top beam using diffraction and interference effects.

[0045] Features: The flat-top beam has a clear edge and uniform energy distribution, effectively improving processing quality.

[0046] Application: In scribing multilayer materials, flat-top beams reduce the heat-affected zone and avoid damage to the underlying structure of perovskite solar cells.

[0047] (3) Focusing function: The unevenness of the perovskite cell surface can cause the focus to shift. The spatial light modulator adjusts the focus position in real time to ensure that the light spot is always accurately focused on the target surface.

[0048] Principle: By changing the phase of the light wave, the position of the beam focus can be dynamically adjusted (moved forward or backward) to adapt to the processing requirements of different heights.

[0049] Features: By combining data from the ranging device, the SLM can achieve independent focus adjustment for multiple light spots, improving processing flexibility and accuracy.

[0050] Application: In the P2 and P3 steps of processing multilayer structures, the focusing function ensures that the processed layer is precisely etched, avoiding damage to the underlying TCO substrate.

[0051] Technical advantages of combined functions: By combining beam splitting, shaping, and focusing functions, the system of this utility model exhibits the following significant advantages:

[0052] High efficiency: Multi-spot parallel processing significantly shortens processing time and improves production efficiency.

[0053] Uniformity: The flat-top beam ensures consistent beam energy, resulting in higher processing quality and better edge sharpness.

[0054] Flexibility: Holograms can be dynamically changed, and the number, spacing, shape, and focal point position of light spots can all be adjusted in real time to adapt to diverse process requirements.

[0055] Adaptability: The focusing function, combined with the ranging device, accurately responds to changes in the height of the processed surface, ensuring the processing accuracy of multi-layer structures.

[0056] Cost optimization: High-efficiency and high-quality processing reduces redundant processing and material waste, resulting in a significant decrease in overall costs.

[0057] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A laser processing system based on a spatial light modulator, characterized in that: It includes a laser (100), a beam expander (200), a spatial light modulator (300), two convex lenses (400), a mirror (500), a focusing objective (600), a moving platform (700), and a ranging device (800); the laser (100) generates a laser beam; the beam expander (200) collimates the laser beam generated by the laser (100) and adjusts the beam spot size, and the beam expander (200) realizes dynamic adjustment of the laser beam to adapt to the requirements of subsequent optical components; the spatial light modulator (300) adjusts the spatial distribution of the laser beam by adjusting the phase and amplitude of the beam; the two convex lenses (400) form a 4F optical system, which is used to adjust the laser beam size so as to converge with the focusing objective. Numerical aperture matching of the focal objective (600); first convex lens: its focal length is equal to the distance from the spatial light modulator (300) to the convex lens; second convex lens: the optical path distance between the convex lens and the first convex lens is equal to the sum of the focal lengths of the two convex lenses; mirror (500) changes the transmission direction of the laser beam, making the beam vertically downward, and finally focused onto the surface of the object to be processed by the focusing objective (600); focusing objective (600) focuses the adjusted laser beam onto the surface to be processed for processing; moving platform (700) is used to fix the object to be processed and supports precise movement along the x and y directions under computer control; ranging device (800) is used to measure the height of the object to be processed to ensure that the focal point of the laser remains consistent on the surface of the object to be processed at different heights.

2. The laser processing system based on a spatial light modulator according to claim 1, characterized in that: The laser (100) is a continuous laser, nanosecond laser, picosecond laser or femtosecond laser with a wavelength range from 450 nm to 1550 nm.

3. The laser processing system based on a spatial light modulator according to claim 1, characterized in that: The spatial light modulator (300) adjusts the shape, phase and focal position of the laser beam, and adjusts the number of beam splits and the beam spacing by loading a hologram. The spatial light modulator (300) splits a beam of light into multiple sub-beams, and enables multiple parallel beams to perform laser processing on the surface of the object to be processed simultaneously.

4. The laser processing system based on a spatial light modulator according to claim 1, characterized in that: The distance from the first convex lens to the reflecting mirror (500) is not equal to the focal length of the first convex lens.

5. The laser processing system based on a spatial light modulator according to claim 1, characterized in that: The ranging device (800) measures the height of the surface of the object to be processed in real time, and the computer adjusts the position of the laser focus according to the height change.

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