Optical fingerprint detection device and preparation method therefor, electronic device

Abstract

The application provides an optical fingerprint detection device and a preparation method thereof and an electronic device, and solves the problem of low fingerprint detection sensitivity in the prior art. The optical fingerprint detection device comprises a first electrode and a second electrode; and a plurality of photosensitive units located between the first electrode and the second electrode, the plurality of photosensitive units are arranged at intervals in a direction parallel to the first electrode and the second electrode, the intervals between the plurality of photosensitive units are filled with a dielectric material, and the dielectric constant of the dielectric material is lower than the dielectric constant of the photosensitive unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fingerprint identification, in particular to an optical fingerprint detection device, a preparation method thereof and an electronic device. BACKGROUND

[0002] As a kind of identity authentication mode of intelligent terminal, optical fingerprint identification gradually replaces conventional password authentication with its convenient and fast characteristics.Optical fingerprint identification includes fingerprint collection and fingerprint identification.Two processes, wherein, the fingerprint collection process includes: the light emitted by light source is irradiated to the user's finger, the light reflected from the user's finger is irradiated to the photosensitive element of pixel circuit through the optical path, and the pixel circuit outputs the electrical signal carrying fingerprint information.

[0003] In the related art, the light emitted from the optical path is only irradiated to part of the area of the photosensitive element, even a small part of the area, while other areas of the photosensitive element are not irradiated by light, that is, only part of the area of the photosensitive element can detect optical fingerprint information.The area without light irradiation will form a larger capacitor, and the existence of the capacitor will reduce the fingerprint detection sensitivity. SUMMARY

[0004] Therefore, the present application provides an optical fingerprint detection device, a preparation method thereof and an electronic device, which solve the problem of low fingerprint detection sensitivity in the prior art.

[0005] The first aspect of the present application provides an optical fingerprint detection device, comprising: a first electrode and a second electrode; and a plurality of photosensitive units located between the first electrode and the second electrode, the plurality of photosensitive units are arranged at intervals in a direction parallel to the first electrode and the second electrode, the intervals between the plurality of photosensitive units are filled with a dielectric material, and the dielectric constant of the dielectric material is lower than that of the photosensitive unit.

[0006] In one embodiment, the dielectric material is a transparent material; preferably, the dielectric material is an elastic material.

[0007] In one embodiment, the optical fingerprint detection device further comprises an optical structure located on the opposite side of the photosensitive unit on the side of the second electrode; the irradiation area of the light emitted from the optical structure covers the photosensitive surface of the photosensitive unit.

[0008] In one embodiment, the optical fingerprint detection device further comprises an optical structure located on the opposite side of the photosensitive unit on the side of the second electrode; the optical structure comprises a plurality of optical paths, and the light emitted from the same optical path is irradiated on the same photosensitive unit.

[0009] In one embodiment, the optical structure comprises a microlens layer, the microlens layer comprises a plurality of microlenses, the microlenses and the photosensitive units correspond one by one, and the corresponding microlenses and photosensitive units are coaxial.

[0010] In one embodiment, the optical structure further comprises a collimating light path layer, the collimating light path layer is located between the microlens layer and the second electrode; the collimating light path layer comprises a first photoresist layer and a second photoresist layer arranged at intervals, and the focal point of the microlens is located between the first photoresist layer and the second photoresist layer.

[0011] In one embodiment, the first photoresist layer is located on the side of the second photoresist layer close to the photosensitive unit; the first photoresist layer comprises a first light transmission hole, and the second photoresist layer comprises a second light transmission hole, and the aperture of the first light transmission hole is larger than the aperture of the second light transmission hole.

[0012] In one embodiment, the light ray fingerprint collection device further comprises an array substrate, and the array substrate comprises a predetermined transistor, and the source or the drain of the predetermined transistor is electrically connected with the first electrode.

[0013] The second aspect of the present application provides a preparation method of an optical fingerprint detection device, comprising: preparing a first electrode; preparing a plurality of photosensitive units spaced from each other on the first electrode; filling a medium material between the photosensitive units; and preparing a second electrode, the second electrode covering the photosensitive units and at least part of the medium material.

[0014] The third aspect of the present application provides an electronic device, comprising: a display screen; and the optical fingerprint detection device provided by any one of the embodiments described above, located on the non-display side of the display screen.

[0015] According to the optical fingerprint detection device and the preparation method thereof and the electronic device provided by the embodiments of the present application, by filling the medium material between the plurality of photosensitive units, the photosensitive material of the area of the conventional photosensitive pixel which cannot be irradiated by the light ray is replaced by the medium material with low dielectric constant, so that the capacitance value of the capacitor formed by the area is reduced. In this case, when the light signal received by the photosensitive pixel is weak and the photocurrent generated is small, the current value is also output in the fingerprint data collection time period. That is to say, even when the light signal is weak, the optical fingerprint detection device still has current output, and the fingerprint information can be detected, thereby improving the detection sensitivity. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The structure schematic diagram of the optical fingerprint detection device in the related art is shown.

[0017] Figure 2 The structure schematic diagram of the APS pixel circuit provided by an embodiment of the present application is shown.

[0018] Figure 3 The structure schematic diagram of the optical fingerprint detection device provided by the first embodiment of the present application is shown.

[0019] Figure 4 The structure schematic diagram of the optical fingerprint detection device provided by the second embodiment of the present application is shown.

[0020] Figure 5 Provided for an embodiment of this application Figure 4 The diagram shows a top view of the optical fingerprint detection device.

[0021] Figure 6 This is a schematic diagram of the structure of the optical fingerprint detection device provided in the third embodiment of this application.

[0022] Figure 7 for Figure 6 A partially enlarged view of the optical fingerprint detection device shown.

[0023] Figure 8 This is a flowchart illustrating a method for fabricating an optical fingerprint detection device according to an embodiment of this application.

[0024] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0025] As described in the background section, only a portion of the photosensitive element can detect optical fingerprint information, while areas without light will form a large capacitance, which reduces the fingerprint detection sensitivity.

[0026] Specifically, see Figure 1 The diagram shows a structural schematic of an optical fingerprint detection device in the related technology. Figure 1 As shown, the optical fingerprint detection device includes an optical structure 1, a photosensitive array layer 2, and an array substrate 3 stacked sequentially. The optical structure 1 includes multiple optical paths 10. The photosensitive array layer 2 includes multiple photosensitive pixels 20, such as photodiodes. The array substrate 3 includes an array of transistors 30, with each predetermined number of transistors 30 connected to a photosensitive pixel 20 to form a pixel circuit. The pixel circuit may be, for example, an active pixel sensor (APS) pixel circuit or a passive pixel sensor (PPS) pixel circuit. It should be understood that, in addition to the transistors 30 and photosensitive pixels 20, the pixel circuit may also include other auxiliary components, such as capacitors. Reflected light from the finger passes through the optical path 10 and illuminates the photosensitive pixel 20, and the pixel circuit outputs an electrical signal carrying fingerprint information.

[0027] See Figure 1At least two adjacent optical paths correspond to the same photosensitive pixel 20, meaning that light emitted from at least two adjacent optical paths 10 illuminates the same photosensitive pixel 20. When multiple beams of light illuminate the same photosensitive pixel 20, these multiple beams of light illuminate multiple areas of the photosensitive pixel 20, and these multiple areas are spaced apart from each other. In other words, only a portion of the photosensitive pixel 20 can receive the light reflected back from the finger, while the areas that do not receive light will form a capacitor.

[0028] Figure 2 This is a schematic diagram of the structure of an APS pixel circuit provided in an embodiment of this application. Figure 2 As shown, the APS pixel circuit includes a photosensitive pixel 20 and three transistors. The photosensitive pixel 20 comprises two parts: a photosensitive unit that receives light, and a capacitor that does not receive light; the photosensitive unit and the capacitor are connected in parallel. The first electrode of the photosensitive pixel 20 is connected to node Q, and the second electrode is connected to the bias voltage terminal Vbias. Transistor T1 is a reset transistor. The control electrode of transistor T1 is connected to the reset signal input terminal Rst, the first electrode of transistor T1 is connected to the power supply signal terminal Vdd, and the second electrode of transistor T1 is connected to node Q. Transistor T2 is an amplification transistor. The control electrode of transistor T2 is connected to node Q, the first electrode of transistor T2 is connected to the power supply signal terminal Vdd, and the second electrode of transistor T2 is connected to the first electrode of the third transistor T3. Transistor T3 operates in a switching state. The control electrode of transistor T3 is connected to the control signal terminal Gate, and the first electrode of transistor T3 is connected to the second electrode of transistor T2. The second electrode of transistor T3 serves as the output terminal Out of the APS pixel circuit 20, outputting the amplified current from transistor T2.

[0029] The operation of the APS detection circuit includes: During the reset period, a reset signal is loaded into the reset signal input terminal Rst to make the electrical position of node Q a reference voltage. During the exposure period, photosensitive pixel 20 receives a light signal and generates a photocurrent, which causes the reference voltage of node Q to drop. During the fingerprint data acquisition period, a scan signal is loaded into the control signal terminal Gate, causing the voltage of node Q to change, and transistor T3 turns on to output current to the output terminal Out.

[0030] During the aforementioned exposure period, capacitor C prevents the reference voltage of node Q from dropping. When the light signal received by photosensitive pixel 20 is weak, the generated photocurrent is small. The effect of the photocurrent causing the reference voltage of node Q to drop is compensated by the capacitor, keeping the reference voltage of node Q constant. Consequently, there is no current output during the fingerprint data acquisition period. In other words, when the light signal is weak, the APS detection circuit has no current output, cannot detect fingerprint information, and has low detection sensitivity.

[0031] In view of this, this application provides an optical fingerprint detection device and its fabrication method and electronic device. By implementing the photosensitive pixel 20 as a plurality of photosensitive units spaced apart from each other, the space between the plurality of photosensitive units is filled with a dielectric material. The dielectric constant of the dielectric material is lower than that of the photosensitive unit, thereby reducing the capacitance value of the parallel capacitor and thus improving the detection sensitivity.

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] Figure 3 This is a schematic diagram of the structure of the optical fingerprint detection device provided in the first embodiment of this application. Figure 3 As shown, the optical fingerprint detection device includes a photosensitive array layer 2, which includes a plurality of photosensitive pixels 20 arranged in an array. Each photosensitive pixel 20 includes a first electrode 21 and a second electrode 22, and a plurality of photosensitive units 23 located between the first electrode 21 and the second electrode 22. When the first electrode 21 is a positive electrode, the second electrode 22 is a negative electrode; when the first electrode is a negative electrode, the second electrode 22 is a positive electrode. The plurality of photosensitive units 23 are spaced apart between the first electrode 21 and the second electrode 22 in a direction parallel to the first electrode 21 and the second electrode 22. The photosensitive unit 23 can be any of a PN junction photodiode, a PIN junction photodiode, or an avalanche photodiode. Taking a PIN junction photodiode as an example, the photosensitive unit 23 specifically includes a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer stacked sequentially. The plurality of or all of the photosensitive pixels 20 in the photosensitive array layer 2 share the same second electrode 22. Of course, each photosensitive pixel 20 can also be provided with a separate second electrode 22.

[0034] The spacing area between the light sensing units 23 is filled with a medium material 24 with low dielectric constant, which is lower than that of the light sensing units 23. In an example, the dielectric constant of the medium material 24 is lower than that of amorphous silicon. The medium material 24 can be a solid material, a gas material or a liquid material. The medium material 24 can further fill the spacing area between the light sensing pixels 20, or other filling materials can be selected for the spacing area between the light sensing pixels 20. The medium material 24 can be transparent or non-transparent. Preferably, the medium material 24 is a transparent material, such as a resin material. Since the medium material can cover the edge area of the light sensing surface of the light sensing units 23 in actual production process, by selecting the medium material 24 as a transparent material, the light collection of the light sensing units 23 can be avoided. In a possible implementation, the medium material 24 is an elastic material. In this case, the flexibility of the optical fingerprint detection device as a whole is improved, and when it is used in a flexible display screen, it can better adapt to the bending of the flexible screen.

[0035] Figure 3 The optical fingerprint detection device shown in the figure is compared with Figure 1 The optical fingerprint detection device shown in the figure is compared with Figure 1 The area of the light sensing pixel 20 that does not receive light in the optical fingerprint detection device shown in the figure is a light sensing material, and in this embodiment, the light sensing material in the area that does not receive light is replaced with a medium material 24 with low dielectric constant, so that the capacitance value of the capacitor formed by the area that does not receive light is reduced. The medium material 24 fills Figure 1 all or part of the area of the light sensing pixel 20 that does not receive light. Preferably, the medium material 24 fills Figure 1 all of the area of the light sensing pixel 20 that does not receive light. In this case, the irradiation area of the light rays emitted from the optical structure 1 covers the light sensing surface of the light sensing unit 23, that is, the entire light sensing surface of the light sensing unit 23 can receive light irradiation, thereby improving the utilization rate of the light sensing pixel 20 and avoiding the formation of a capacitor due to the lack of light irradiation.

[0036] According to the optical fingerprint detection device provided in this embodiment, the light sensing material in the area that cannot be irradiated with light is replaced with a medium material 24, so that the capacitance value of the capacitor formed by the area is reduced. In this case, referring to Figure 2 When the light signal received by the light sensing pixel 20 is weak and the photocurrent generated is small, the capacitor is also not sufficient to compensate for the effect of the reference voltage drop of the node Q caused by the photocurrent, thereby outputting the current value in the fingerprint data acquisition time period. That is, even when the light signal is weak, the APS detection circuit still has current output, and the fingerprint information can be detected, thereby improving the detection sensitivity.

[0037] As Figure 3The optical fingerprint detection device also includes an array substrate 3, which includes a plurality of transistors arranged in an array, including a predetermined transistor, for example Figure 2 The source or drain of the predetermined transistor is connected to the first electrode 21 of the photosensitive pixel 20, constituting a pixel circuit.

[0038] Figure 4 The optical fingerprint detection device provided by the second embodiment of the present application is shown in the structural schematic diagram. As shown in the figure Figure 4 The optical fingerprint detection device is based on the optical fingerprint detection device shown in the figure Figure 3 The optical fingerprint detection device further includes an optical structure 1 on the side opposite to the side where the photosensitive unit 23 of the second electrode 22 is located. The optical structure 1 includes a plurality of light paths 10, which are the propagation paths of light rays. The light path 10 and the photosensitive unit 23 correspond one by one, that is, the light rays emitted in one light path 10 are all received by the same photosensitive unit 23. In this way, the problem of light crosstalk between light paths can be avoided, and the fingerprint collection accuracy can be improved.

[0039] Specifically, as shown in the figure Figure 4 The optical structure 1 includes a microlens layer 11, which includes a plurality of microlenses 110. The microlens 110 has a light condensing effect, and each microlens 110 corresponds to a light path 10. The light rays incident from the same microlens 110 are irradiated onto the photosensitive surface of the same photosensitive unit 23. The microlens 110 and the photosensitive unit 23 corresponding to each other are coaxial. The photosensitive unit 23 is columnar, and the "coaxial line of the microlens 110 and the photosensitive unit 23" refers to the center axis of the microlens 110 coinciding with the center axis of the photosensitive unit 23.

[0040] Optionally, as shown in the figure Figure 4 The optical structure 1 can also include a collimated light path layer 12 stacked between the microlens layer 11 and the second electrode 22. In this embodiment, as shown in the figure Figure 4 The collimated light path layer 12 includes a first photoresist layer BM1 and a second photoresist layer BM2 arranged at intervals, and the focal point of the microlens 110 is located between the first photoresist layer BM1 and the second photoresist layer BM2. By arranging two photoresist layers and arranging the focal point of the microlens 110 between the two photoresist layers, a compromise can be achieved between ensuring the collimation effect of the light rays and reducing light loss, and the overall light collection effect can be optimized. The first photoresist layer BM1 is located on the side of the second photoresist layer BM2 close to the photosensitive unit 23, the first photoresist layer BM1 includes a first light transmission hole Q1, the second photoresist layer BM2 includes a second light transmission hole Q2, and the aperture of the first light transmission hole Q1 is larger than the aperture of the second light transmission hole Q2. In this way, the second light transmission hole Q2 with a smaller aperture can be used to filter out light rays with a large angle, and the anti-crosstalk effect is better.

[0041] Figure 5Provided for an embodiment of this application Figure 4 The diagram shows a top view of the optical fingerprint detection device. (Combined with...) Figure 4 and Figure 5 As shown, the microlens 110, the second light-transmitting aperture Q2, the first light-transmitting aperture Q1, and the photosensitive unit 23 are coaxial. Light rays incident perpendicular to the surface of the microlens 110 pass sequentially through the centers of the second light-transmitting aperture Q2 and the first light-transmitting aperture Q1, illuminating the central axis of the photosensitive unit 23. The photosensitive surfaces of the photosensitive units 23 in the same photosensitive pixel 20 have equal areas and the same shape. The shape of the photosensitive surface of the photosensitive unit 23 can be any shape such as a rectangle, circle, or polygon. In one possible implementation, the shape of the photosensitive surface of the photosensitive unit 23 is the same as the shape of the illuminating surface of the light rays emitted from the light path on the photosensitive unit 23, for example, both are circular.

[0042] Figure 6 This is a schematic diagram of the structure of the optical fingerprint detection device provided in the third embodiment of this application. Figure 7 for Figure 6 A partially enlarged view of the optical fingerprint detection device shown. (Combined with...) Figure 6 and Figure 7 As shown, the optical fingerprint detection device includes an optical structure 1, a photosensitive array layer 2, and an array substrate 3 stacked sequentially. (See reference...) Figure 7 The array substrate 3 includes a substrate 301, a channel layer 302, a gate insulating layer 303, a gate 304, an interlayer dielectric layer 305, a source and a drain located on the same electrode layer 306, and a first protective layer 307, stacked sequentially. The first protective layer 307 has multiple openings to expose the source or drain. The photosensitive array layer 2 includes a first electrode 21 extending from the source or drain, photosensitive units 23 stacked on the first electrode 21, a second protective layer 201 covering the photosensitive units 23 and the first protective layer 307, and a dielectric material 24 covering the second protective layer 201 and filling the gaps between the photosensitive units 23. The second protective layer 201 has openings corresponding to the area of ​​each photosensitive unit 23 to expose the photosensitive unit 23. The photosensitive array layer 2 also includes a second electrode 22 covering the photosensitive units 23 and at least a portion of the dielectric material 24, and a second protective layer 202 covering the second electrode 22. (See reference...) Figure 6 The optical structure 1 includes a first transparent embedded layer 101, a first photoresist layer BM1, a second transparent embedded layer 102, a second photoresist layer BM2, a third transparent embedded layer 103, and a microlens layer 11, which are sequentially stacked on the second protective layer 202.

[0043] This application also provides a method for fabricating an optical fingerprint detection device. Figure 8 This is a flowchart illustrating a method for fabricating an optical fingerprint detection device according to an embodiment of this application. Figure 8 As shown, the preparation method 800 includes:

[0044] Step S810, a first electrode 21 is prepared.

[0045] Referring to Figure 6 and Figure 7 The first electrode is prepared on a preset substrate. The preset substrate can be an array substrate 3, which includes a transistor array. The surface of the array substrate 3 is a first protective layer 307. In this case, the process of preparing the first electrode 21 on the preset substrate can be removing the first protective layer 307 in a predetermined region to expose the first electrode 21. The first electrode 21 can be an area extending from the source or drain of a predetermined transistor in the array substrate 3 to realize the electrical connection between the first electrode 21 and the source (or drain). It should be noted that the preparation of the first electrode 21 can also be performed after the preparation of the array substrate is completed, and the electrical connection between the first electrode 21 and the source or drain can be realized.

[0046] Step S820, a plurality of photosensitive units 23 spaced from each other are prepared on the first electrode 21.

[0047] For example, a semiconductor layer is deposited on the first electrode 21, and the semiconductor layer is doped to obtain a structure in which a P-type semiconductor, an I-type semiconductor, and an N-type semiconductor are sequentially stacked. A photolithography process is used to etch the semiconductor layer to obtain a plurality of photosensitive units 23 spaced from each other, each of which includes a P-type semiconductor, an I-type semiconductor, and an N-type semiconductor layer structure sequentially stacked.

[0048] Step S830, a medium material 24 is filled between the photosensitive units 23.

[0049] The dielectric constant of the medium material 24 is lower than that of amorphous silicon. The medium material is, for example, resin. The medium material 24 can be transparent or opaque. Preferably, the medium material 24 is a transparent material. Since the edge region of the light-sensing surface of the photosensitive unit 23 can be covered by the medium material in the actual preparation process, the light collection of the photosensitive unit 23 can be avoided by selecting the medium material 24 as a transparent material. In a possible implementation, the medium material 24 is an elastic material. In this case, the flexibility of the optical fingerprint detection device as a whole is improved, and when it is used in a flexible display screen, it can better adapt to the bending of the flexible screen.

[0050] Step S840, a second electrode 22 is prepared, which covers the photosensitive units and at least part of the medium material.

[0051] The first electrode 21 and the second electrode 22 respectively serve as the negative electrode and the positive electrode of the photosensitive pixel 20.

[0052] In one embodiment, before step S830 is performed, a second protective layer 201 is prepared to cover the photosensitive units 23 and the pre-prepared substrate. Then, according to step S830, a medium layer is formed by filling medium material between the photosensitive units 23. In this case, the medium layer covers the second protective layer 201. The second protective layer 201 functions as insulation and water-oxygen barrier. The material of the second protective layer 201 is, for example, silicon nitride, silicon carbide, silicon oxynitride, etc. In this case, before step S840 is performed, a plurality of openings are prepared on the second protective layer 201, each of which exposes one photosensitive unit 23. Then, according to step S840, a second electrode 23 is prepared to cover the plurality of photosensitive units 23 and the medium layer.

[0053] In one embodiment, before step S810 is performed, a step of preparing the pre-prepared substrate is further included. The step of preparing the pre-prepared substrate can be implemented in a conventional manner, which is not described here in detail.

[0054] In another embodiment, after step S840 is performed, a step of preparing the optical fingerprint detection device 1 is further included. The step of preparing the optical fingerprint detection device 1 can be implemented in a conventional manner, which is not described here in detail.

[0055] According to the method for preparing the optical fingerprint detection device provided in the embodiment, by implementing one photosensitive pixel 20 as a plurality of photosensitive units 23 and filling the space between the photosensitive units 23 with medium material 24 of low dielectric constant, the capacitance value of the area filled with the medium material 24 is reduced. In this case, referring to Figure 2 When the light signal received by the photosensitive pixel 20 is weak and the photoelectric current generated is small, the capacitance is also not sufficient to compensate for the effect of the drop of the reference voltage of the node Q caused by the photoelectric current, so as to output the current value in the fingerprint data collection period. That is, even when the light signal is weak, the APS detection circuit still has current output, and the fingerprint information can be detected, so as to improve the detection sensitivity.

[0056] The application further provides an electronic device. Figure 9 The structure schematic diagram of the electronic device provided in an embodiment of the application is shown in FIG. 9. As shown in FIG. 9, the electronic device 90 includes a display screen 91 and an optical fingerprint detection device 92 located on the non-display side of the display screen 91. The optical fingerprint detection device can be any of the optical fingerprint detection devices provided in the above embodiments. Figure 9

[0057] ​The working process of the electronic device 90 is, for example, that the position on the display screen 91 corresponding to the optical fingerprint detection device 92 is a sensing area S. When a finger is pressed onto the sensing area S of the display screen 91, the display screen 91 is lighted, the light emitted by the display screen 91 irradiates the finger, the light reflected by the finger is collected by the photosensitive pixels 20 in the optical fingerprint detection device 92, and an electrical signal carrying fingerprint information is outputted for subsequent fingerprint identification.

[0058] The foregoing description has been presented for the purposes of illustration and description. Furthermore, the description is not intended to limit the embodiments of the application to the forms disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations of the described aspects and embodiments.

Claims

1. An optical fingerprint detection device, characterized in that, Comprising: a first electrode and a second electrode; and a plurality of light sensing units located between the first electrode and the second electrode, the plurality of light sensing units are spaced apart in a direction parallel to the first electrode and the second electrode, the space between the plurality of light sensing units is filled with a dielectric material, the dielectric constant of the dielectric material is lower than the dielectric constant of the light sensing units; at least two adjacent light sensing units correspond to the same light sensing pixel.

2. The optical fingerprint detection device according to claim 1, characterized in that, The dielectric material covers the edge region of the light sensing surface of the light sensing unit, and the dielectric material is a transparent material.

3. The optical fingerprint detection device according to claim 1, characterized in that, The dielectric material is an elastic material.

4. The optical fingerprint detection device according to any one of claims 1-3, wherein, Further comprising an optical structure located on the opposite side of the light sensing unit side of the second electrode; the illumination area of the light rays emitted from the optical structure covers the light sensing surface of the light sensing unit.

5. The optical fingerprint detection device according to any one of claims 1-3, wherein, Further comprising an optical structure located on the opposite side of the light sensing unit side of the second electrode; the optical structure comprises a plurality of light paths, and the light rays emitted from the same light path illuminate on the same light sensing unit.

6. The optical fingerprint detection device according to claim 5, wherein The optical structure comprises a microlens layer, the microlens layer comprises a plurality of microlenses, the microlenses and the light sensing units correspond one by one, and the corresponding microlenses and light sensing units are coaxial.

7. The optical fingerprint detection device according to claim 6, characterized in that The optical structure further comprises a collimating light path layer located between the microlens layer and the second electrode; the collimating light path layer comprises a first light blocking layer and a second light blocking layer spaced apart, and the focal point of the microlens is located between the first light blocking layer and the second light blocking layer.

8. The optical fingerprint detection device according to claim 7, characterized in that The first light blocking layer is located on the side of the second light blocking layer close to the light sensing unit; the first light blocking layer comprises a first light transmission hole, and the second light blocking layer comprises a second light transmission hole, and the aperture of the first light transmission hole is larger than the aperture of the second light transmission hole.

9. The optical fingerprint detection device according to any one of claims 1-3, wherein, Further comprising an array substrate, the array substrate comprises a predetermined transistor, and the source or drain of the predetermined transistor is electrically connected with the first electrode.

10. A method of manufacturing an optical fingerprint detection device, characterized by, Comprising: preparing a first electrode; preparing a plurality of light sensing units spaced apart from each other on the first electrode; filling a dielectric material between the light sensing units; preparing a second electrode covering the light sensing units and at least part of the dielectric material; at least two adjacent light sensing units correspond to the same light sensing pixel.

11. An electronic device, comprising: Comprising: a display screen; and The optical fingerprint detection device of any one of claims 1-9 is located on the non-display side of the display screen.

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