Photoelectric sensing substrate, sensing method thereof and display device

Abstract

The invention discloses a photoelectric sensing substrate, a sensing method thereof and a display device. The photoelectric sensing substrate comprises a substrate, a sensing circuit and a photoelectric sensing element which are sequentially stacked on one side of the substrate; the sensing circuit comprises a scanning line, a reading line, a grounding line and a first transistor; the first transistor comprises a first grid electrode, a first electrode and a second electrode; the photoelectric sensing element comprises a first electrode, an organic photoelectric conversion layer and a second electrode, and the first electrode, the organic photoelectric conversion layer and the second electrode are sequentially stacked in the direction away from the substrate; the sensing circuit also includes a second transistor including a second gate, a third pole, and a fourth pole; the first gate and the second gate are electrically connected with the scanning line; the first pole and the third pole are electrically connected with the first electrode; the second electrode is electrically connected with the reading line; the fourth pole is electrically connected with a grounding wire; the first transistor can be turned on when the photoelectric sensing element works, and the second transistor can be turned on when the photoelectric sensing element does not work. The photoelectric sensing substrate can ensure that the photoelectric sensing element is kept in an optimal state before working.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the field of photoelectric sensing technology, and particularly relate to a photoelectric sensing substrate, a sensing method thereof, and a display device. Background Art

[0002] The EQE (External Quantum Efficiency) of a photomultiplier tube (OPD) (Organic Photodetector), which is the ratio of the number of collected electrons to the number of incident photons, is significantly affected by bias voltage (i.e., the voltage difference between the two electrodes of the photomultiplier tube when the photocurrent reading terminal is connected to zero potential). The photocurrent reading terminal of the photomultiplier tube is electrically connected to a transistor, which controls the output of the photocurrent by turning the transistor on or off. When the photomultiplier tube and transistor are integrated, photogenerated charge accumulates when exposed to external light, resulting in a decrease in the initial voltage difference between the two electrodes of the photomultiplier tube, thereby affecting the EQE of the photomultiplier tube. Summary of the Invention

[0003] Embodiments of the present disclosure provide a photoelectric sensing substrate, a sensing method thereof, and a display device.

[0004] In a first aspect, an embodiment of the present disclosure provides a photoelectric sensing substrate, comprising a base,

[0005] The sensing circuit and the photoelectric sensing element are sequentially stacked on one side of the substrate;

[0006] The sensing circuit includes a scan line, a read line, a ground line and a first transistor;

[0007] The first transistor includes a first gate, a first electrode and a second electrode;

[0008] The photoelectric sensing element includes a first electrode, an organic photoelectric conversion layer, and a second electrode, wherein the first electrode, the organic photoelectric conversion layer, and the second electrode are stacked in sequence in a direction away from the substrate;

[0009] The sensing circuit further includes a second transistor, wherein the second transistor includes a second gate, a third electrode, and a fourth electrode;

[0010] The first gate and the second gate are electrically connected to the scan line; the first electrode and the third electrode are electrically connected to the first electrode; the second electrode is electrically connected to the read line; and the fourth electrode is electrically connected to the ground line.

[0011] The first transistor can be turned on when the photoelectric sensing element is working, and the second transistor can be turned on when the photoelectric sensing element is not working.

[0012] In some embodiments, the first transistor comprises a P-type transistor, and the second transistor comprises an N-type transistor.

[0013] Alternatively, the first transistor comprises an N-type transistor, and the second transistor comprises a P-type transistor.

[0014] In some embodiments, the first transistor comprises a low-temperature polysilicon transistor, an oxide semiconductor transistor, an amorphous silicon transistor, or a field effect transistor.

[0015] The second transistor comprises a low-temperature polysilicon transistor, an oxide semiconductor transistor, an amorphous silicon transistor, or a field effect transistor.

[0016] In some embodiments, the number of the optoelectric sensing elements is plural, and the plural optoelectric sensing elements are arranged in an array.

[0017] The scan lines, the read lines, and the ground lines each comprise a plurality of lines.

[0018] One of the scan lines is electrically connected to one row of the optoelectric sensing elements.

[0019] One of the read lines is electrically connected to one column of the optoelectric sensing elements.

[0020] One of the ground lines is electrically connected to one column of the optoelectric sensing elements.

[0021] In some embodiments, the sensing circuit further comprises at least one capacitor,

[0022] The capacitor comprises a first electrode plate and a second electrode plate,

[0023] The first electrode plate is electrically connected to the first electrode, and the second electrode plate is electrically connected to the second electrode.

[0024] In some embodiments, the material of the organic photoelectric conversion layer comprises PTAA or TPAFS-TMA.

[0025] The material of the acceptor in the organic photoelectric conversion layer comprises Y6, PC61BM, or PC71BM.

[0026] The material of the first electrode comprises indium tin oxide or a laminated material of indium tin oxide, silver, and indium tin oxide.

[0027] The material of the second electrode comprises aluminum.

[0028] In some embodiments, the thickness of the second electrode ranges from 10 nm to 30 nm.

[0029] In some embodiments, the first gate of the low-temperature polysilicon transistor is disposed in the same layer as the scan line.

[0030] The second gate of the oxide semiconductor transistor is located on a side of the first gate away from the substrate, and an insulating layer is provided between the first gate and the second gate;

[0031] A via hole is provided in the insulating layer, and the second gate is electrically connected to the scan line through the via hole.

[0032] In a second aspect, an embodiment of the present disclosure further provides a display device comprising the above-mentioned photoelectric sensing substrate.

[0033] In a third aspect, an embodiment of the present disclosure further provides a photoelectric sensing method for the above-mentioned photoelectric sensing substrate, comprising: when the photoelectric sensing element is not working, a signal on the scanning line turns on the second transistor, and the electrical signal output by the photoelectric sensing element is grounded through a ground line;

[0034] When the photoelectric sensing element is working, the signal on the scanning line turns on the first transistor, and the electrical signal output by the photoelectric sensing element is output through the reading line.

[0035] The photoelectric sensing substrate provided in this embodiment, by providing a second transistor in the sensing circuit and enabling the second transistor to be turned on when the photoelectric sensing element is not operating, can conduct the light sensing current generated by the photoelectric sensing element under light to the ground terminal through the second transistor and the ground line, thereby preventing the photogenerated voltage formed by the accumulation of photogenerated charges in the photoelectric sensing element under light from offsetting the original bias voltage applied to the first and second electrode terminals of the photoelectric sensing element. In other words, the photogenerated charges of the photoelectric sensing element when not operating prevent the original bias voltage of the photoelectric sensing element from being reduced, thereby preventing the original bias voltage of the first and second electrode terminals of the photoelectric sensing element from being insufficient when the photoelectric sensing element starts operating, and further preventing the reduction of the EQE of the photoelectric sensing element due to the insufficient original bias voltage, thereby ensuring that the photoelectric sensing element remains in an optimal state before operation.

[0036] The display device provided in this embodiment, by adopting the above-mentioned photoelectric sensing substrate, can realize touch control of the display device by touch objects such as fingerprints, thereby realizing effective sensing of touch objects such as fingerprints by the display device and improving the photoelectric sensing effect of the display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation of the present disclosure. The above and other features and advantages will become more apparent to those skilled in the art by describing the detailed exemplary embodiments with reference to the accompanying drawings, in which:

[0038] Figure 1aThis is the current density curve of the amorphous silicon photodiode under different light intensities and bias voltages.

[0039] Figure 1b EQE curve of amorphous silicon photodiode under different bias voltages.

[0040] Figure 1c This is the current density curve of the photomultiplier tube under different light intensities and bias voltages.

[0041] Figure 1d The graph is a curve of the light sensing value change of the photomultiplier tube when the transistor electrically connected to it is turned on.

[0042] Figure 1e This is a timing diagram of the turn-on timing of the transistor electrically connected to the photomultiplier tube and the acquisition timing of the photomultiplier tube light sensing current signal in the related art.

[0043] Figure 2a FIG. 4 is a partial cross-sectional schematic diagram of a photoelectric sensing substrate in an embodiment of the present disclosure.

[0044] Figure 2b FIG. 4 is a circuit diagram of a photoelectric sensing element and a sensing circuit in a photoelectric sensing substrate according to an embodiment of the present disclosure.

[0045] Figure 3a FIG. 4 is a top view schematically illustrating the arrangement of photoelectric sensing elements in a photoelectric sensing substrate according to an embodiment of the present disclosure.

[0046] Figure 3b FIG. 1 is a partial top view of a sensing circuit in a photoelectric sensing substrate according to an embodiment of the present disclosure.

[0047] Figure 3c For the Figure 3b Schematic diagram of the cross section along the AA' section line.

[0048] Figure 4a Schematic diagram of a preparation process of a photoelectric sensing substrate in an embodiment of the present disclosure.

[0049] Figure 4b Schematic diagram of the preparation process of the sensing circuit in the photoelectric sensing substrate according to an embodiment of the present disclosure.

[0050] Figure 4c Schematic diagram of another preparation process of a photoelectric sensing substrate in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, a photoelectric sensing substrate, a sensing method thereof, and a display device provided by the embodiments of the present disclosure are further described in detail below with reference to the accompanying drawings and specific implementation plans.

[0052] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0053] Embodiments of the present disclosure are not limited to the embodiments shown in the drawings, but include modifications of configurations formed based on manufacturing processes. Therefore, the regions exemplified in the drawings have a schematic property, and the shape of the regions shown in the drawings exemplifies a specific shape of the regions, but is not intended to be restrictive.

[0054] Combining the glass-based transistor with the photodetector reduces the manufacturing cost and is suitable for mass production.

[0055] The IV (current-voltage characteristic, a key indicator for evaluating the electrical performance of a photomultiplier by applying a voltage and measuring a current response) test results of the photomultiplier show that the light response of the photomultiplier is higher than that of the PIN (photodiode), but the light response of the photomultiplier device integrated with the transistor (i.e., the light sensing current reading end of the photomultiplier is electrically connected to the transistor) is not as good as that of the photodiode. The analysis reason is that the photomultiplier array turns on the transistor by row-by-row scanning to realize the output of the light sensing current of each row of photomultipliers. When the other rows of photomultipliers are not turned on, the photovoltage formed by the accumulation of photo-generated charges offsets the original bias voltage applied to the two electrode ends of the photomultiplier, resulting in insufficient bias voltage of the photomultiplier when it is turned on, and reduced EQE (External Quantum Efficiency, the ratio of the number of collected electrons to the number of incident photons).

[0056] At present, a fingerprint recognition device is made by using a transistor (TFT) + amorphous silicon photodiode (PIN) structure. The reverse bias current of the photodiode increases with the increase of light under different light, as shown in Figure 1a and Figure 1b The reverse bias current of the photodiode is almost unchanged in the range of -6V~0V of the reverse bias voltage (i.e., the voltage difference between the two electrode ends of the photodiode when the light sensing current reading end is connected to zero potential); this feature can also be reflected in the EQE curve of the photodiode, i.e., the difference of the EQE of the photodiode under different bias is not large. In addition, the EQE of the amorphous silicon photodiode is less than 100%, and the absorption spectrum is not adjustable.

[0057] The photomultiplier has the advantages of EQE greater than 100% and adjustable absorption spectrum. The photoelectric conversion layer of the photomultiplier can be prepared in a large area by spin coating or blade coating. However, the EQE of the photomultiplier is greatly affected by the bias voltage of the device, as shown in Figure 1cAs shown in the figure, the light sensing current of the photomultiplier tube under 2V bias and 6V bias has two orders of magnitude difference, which seriously affects the EQE characteristics of the photomultiplier tube. The conventional 1T1C circuit (i.e., one TFT is electrically connected to the light sensing current reading terminal of the photomultiplier tube, and a capacitor is connected in parallel with the photomultiplier tube) cannot bring out its maximum advantage. Figure 1d and Figure 1e As shown, when testing the system, it is necessary to delay the acquisition of the light sensing current signal for a period of time after the transistor is turned on. The longer the time between transistor turning on and light sensing current signal acquisition (i.e., Tgate - Tcds2), the less impact the photoelectric voltage formed by the accumulated photogenerated charge will have on the original bias voltage applied to the two electrodes of the photomultiplier tube, and the higher the photoelectric conversion efficiency. However, using this delayed signal acquisition method will affect the refresh rate of the photomultiplier tube array, thereby affecting the fingerprint recognition speed.

[0058] In order to solve the above problems in the related art, in a first aspect, the present disclosure provides a photoelectric sensing substrate, such as Figure 2a and Figure 2b As shown, the photoelectric sensing substrate includes a substrate 1, a sensing circuit 2 and a photoelectric sensing element 3, which are stacked on one side of the substrate 1 in sequence; the sensing circuit 2 includes a scanning line 21, a reading line 22, a grounding line 23 and a first transistor 24; the first transistor 24 includes a first gate 241, a first electrode 242 and a second electrode 243; the photoelectric sensing element 3 includes a first electrode 31, an organic photoelectric conversion layer 32 and a second electrode 33, and the first electrode 31, the organic photoelectric conversion layer 32 and the second electrode 33 are stacked in sequence in a direction away from the substrate 1; the sensing circuit 2 also includes a second transistor 25, the second transistor 25 includes a second gate 251, a third electrode 252 and a fourth electrode 253; the first gate 241 and the second gate 251 are electrically connected to the scanning line 21; the first electrode 242 and the third electrode 252 are electrically connected to the first electrode 31; the second electrode 243 is electrically connected to the reading line 22; and the fourth electrode 253 is electrically connected to the grounding line 23; the first transistor 24 can be turned on when the photoelectric sensing element 3 is working, and the second transistor 25 can be turned on when the photoelectric sensing element 3 is not working.

[0059] The photoelectric sensing element 3 may be a photomultiplier tube and may be used in applications such as fingerprint recognition.

[0060] In some embodiments, the material of the organic photoelectric conversion layer 32 includes PTAA or TPAFS-TMA; the material of the acceptor in the organic photoelectric conversion layer 32 includes Y6, PC61BM or PC71BM; the material of the first electrode 31 includes indium tin oxide or a stacked material of indium tin oxide, silver and indium tin oxide; and the material of the second electrode 33 includes aluminum.

[0061] In some embodiments, the thickness of the second electrode 33 ranges from 10 to 30 nm. The thickness of the second electrode 33 is thin enough to allow external light to pass through the second electrode 33 and illuminate the organic photoelectric conversion layer 32, thereby enabling the organic photoelectric conversion layer 32 to convert the light signal into a current signal and output the current signal through the first electrode 31 so that the current signal can be read by the read line 22.

[0062] In this embodiment, by providing a second transistor 25 in the sensing circuit 2 and enabling the second transistor 25 to be turned on when the photoelectric sensing element 3 is not operating, the light sensing current generated by the photoelectric sensing element 3 under illumination can be conducted to the ground terminal through the second transistor 25 and the ground line 23. This prevents the photoelectric voltage formed by the accumulation of photogenerated charges in the photoelectric sensing element 3 under illumination from offsetting the original bias voltage applied to the first electrode 31 and the second electrode 33 of the photoelectric sensing element 3. In other words, this prevents the photogenerated charges in the photoelectric sensing element 3 when not operating from causing a decrease in its original bias voltage. This further prevents the original bias voltage at the first electrode 31 and the second electrode 33 of the photoelectric sensing element 3 from being insufficient when the photoelectric sensing element 3 starts operating, thereby preventing a decrease in the EQE of the photoelectric sensing element 3 due to the insufficient original bias voltage. Ultimately, this ensures that the photoelectric sensing element 3 remains in an optimal state before operation.

[0063] In some embodiments, the first transistor 24 comprises a P-type transistor and the second transistor 25 comprises an N-type transistor. With this arrangement, when a negative voltage signal is input to the scan line 21, the first transistor 24 is turned on and the second transistor 25 is turned off; when a positive voltage signal is input to the scan line 21, the first transistor 24 is turned off and the second transistor 25 is turned on.

[0064] In some embodiments, the first transistor 24 comprises an N-type transistor and the second transistor 25 comprises a P-type transistor. With this arrangement, when a negative voltage signal is input to the scan line 21, the first transistor 24 is turned off and the second transistor 25 is turned on; when a positive voltage signal is input to the scan line 21, the first transistor 24 is turned on and the second transistor 25 is turned off.

[0065] In some embodiments, the first transistor 24 includes a low-temperature polysilicon transistor, an oxide semiconductor transistor, an amorphous silicon transistor, or a field-effect transistor; the second transistor 25 includes a low-temperature polysilicon transistor, an oxide semiconductor transistor, an amorphous silicon transistor, or a field-effect transistor.

[0066] When the first transistor 24 and the second transistor 25 are oxide semiconductor transistors, they can only be manufactured as N-type transistors.

[0067] In some embodiments, as Figure 3aAs shown, there are multiple photoelectric sensing elements 3, and the multiple photoelectric sensing elements 3 are arranged in an array; the scanning lines 21, the reading lines 22 and the grounding lines 23 each include multiple lines; one scanning line 21 is electrically connected to a row of photoelectric sensing elements 3; one reading line 22 is electrically connected to a column of photoelectric sensing elements 3; and one grounding line 23 is electrically connected to a column of photoelectric sensing elements 3.

[0068] With this arrangement, the array of photoelectric sensing elements 3 can be driven by row-by-row scanning during operation. For example, when the photoelectric sensing elements 3 in the nth row are driven by a signal on the scan line 21, the photoelectric sensing elements 3 in that row output a light-sensing current signal via the readout line 22. Simultaneously, the ground line 23 connected to the photoelectric sensing elements 3 in that row does not output a light-sensing current signal. Since the photoelectric sensing elements 3 in other rows are not driven by a signal on the scan line 21, the photoelectric sensing elements 3 in other rows do not output a light-sensing current signal via the readout line 22. The ground lines 23 connected to the photoelectric sensing elements 3 in other rows ground their light-sensing current signals when illuminated.

[0069] In some embodiments, as Figure 2a As shown, the sensing circuit 2 further includes at least one capacitor 26, which includes a first plate and a second plate. The first plate is electrically connected to the first electrode 31, and the second plate is electrically connected to the second electrode 33. The capacitor 26 can store the photoelectric charge generated by the photoelectric sensing element 3 under light on its plates, so that the reading line 22 can read the light sensing current signal.

[0070] In some embodiments, as Figure 3b and Figure 3c As shown, the first gate 241 of the low-temperature polysilicon transistor and the scan line 21 are arranged in the same layer, the second gate 251 of the oxide semiconductor transistor is located on the side of the first gate 241 away from the substrate 1, and an insulating layer 27 is provided between the first gate 241 and the second gate 251; a via 270 is provided in the insulating layer 27, and the second gate 251 is electrically connected to the scan line 21 through the via 270.

[0071] In some embodiments, both the first transistor 24 and the second transistor 25 are top-gate transistors. A first gate insulating layer 271 is disposed between the active layer 244 and the first gate 241 of the first transistor 24. A first interlayer dielectric layer 272, a buffer layer 273, a second gate insulating layer 274, and a second interlayer dielectric layer 275 are disposed between the first gate 241 and the first and second electrodes 242 and 243. A second gate insulating layer 274 is disposed between the active layer 254 and the second gate 251 of the second transistor 25. A second interlayer dielectric layer 275 is disposed between the second gate 251 and the third and fourth electrodes 252 and 253. The insulating layer 27 between the first and second gates 241 and 251 includes a first interlayer dielectric layer 272, a buffer layer 273, and a second gate insulating layer 274. An insulating layer 27 is also provided between the first pole 242, the second pole 243, the third pole 252, the fourth pole 253 and the first electrode 31. The insulating layer 27 between the first pole 242, the second pole 243, the third pole 252, the fourth pole 253 and the first electrode 31 includes a first passivation layer 276, a flat layer 277 and a second passivation layer 278 stacked in sequence.

[0072] In some embodiments, the substrate 1 may be a glass substrate or a flexible substrate, such as a flexible substrate formed by stacking a polyimide layer and a resistance layer.

[0073] Based on the photoelectric sensing substrate of the above structure, an embodiment of the present disclosure also provides a photoelectric sensing method of the photoelectric sensing substrate, including: when the photoelectric sensing element is not working, the signal on the scanning line turns on the second transistor, and the electrical signal output by the photoelectric sensing element is grounded through the ground line; when the photoelectric sensing element is working, the signal on the scanning line turns on the first transistor, and the electrical signal output by the photoelectric sensing element is output through the reading line.

[0074] The electrical signal outputted from the read line is provided to the sensing control circuit so as to acquire the touch object (such as a fingerprint) touching the photoelectric sensing substrate.

[0075] In some embodiments, the array of photoelectric sensing elements 3 is driven by row-by-row scanning. When a row of photoelectric sensing elements 3 is driven for fingerprint sensing, the photoelectric sensing current signals of the photoelectric sensing elements 3 in other rows are grounded through ground wires under light, thereby ensuring that the photoelectric sensing elements 3 in other rows are maintained in the optimal state before operation.

[0076] Based on the above structure of the photoelectric sensing substrate, the embodiment of the present disclosure further provides a method for preparing the photoelectric sensing substrate. When the first transistor is a low-temperature polysilicon transistor, the second transistor is an oxide semiconductor transistor, and both the first transistor and the second transistor are top-gate transistors, the method for preparing the photoelectric sensing substrate includes: Figure 4a and Figure 4bAs shown, the active layer 244 of the first transistor, the first gate 241 and the scan line 21, the active layer 254 of the second transistor, the second gate 251, the first pole 242 and the second pole 243, the third pole 252 and the fourth pole 253, and the first electrode 31 are sequentially prepared on the substrate 1 by a traditional patterning process; then the organic photoelectric conversion layer 32 is prepared by a spin coating or a scraping process; and then the second electrode 33 is formed by vapor deposition.

[0077] The readout line 22 and the ground line 23 are formed together with the first electrode 242 and the second electrode 243 by a single patterning process. The insulating layer between any two adjacent conductive layers and the vias therein are formed by conventional patterning processes, which will not be described in detail here.

[0078] In some embodiments, when the first transistor and the second transistor are both low-temperature polysilicon transistors, and the first transistor and the second transistor are both top-gate transistors, the method for preparing the photoelectric sensing substrate includes: Figure 4c As shown, the active layer 244 of the first transistor and the active layer 254 of the second transistor, the first gate 241 and the second gate 251, the scanning line 21, the first pole 242 and the second pole 243, the third pole 252 and the fourth pole 253, and the first electrode 31 are sequentially prepared on the substrate 1 by a traditional patterning process; then the organic photoelectric conversion layer 32 is prepared by a spin coating or a scraping process; and then the second electrode 33 is formed by evaporation.

[0079] The readout line 22 and the ground line 23 are formed together with the first electrode 242 and the second electrode 243 by a single patterning process. The insulating layer between any two adjacent conductive layers and the vias therein are formed by conventional patterning processes, which will not be described in detail here.

[0080] The photoelectric sensing substrate provided in this embodiment, by providing a second transistor in the sensing circuit and enabling the second transistor to be turned on when the photoelectric sensing element is not operating, can conduct the light sensing current generated by the photoelectric sensing element under light to the ground terminal through the second transistor and the ground line, thereby preventing the photogenerated voltage formed by the accumulation of photogenerated charges in the photoelectric sensing element under light from offsetting the original bias voltage applied to the first and second electrode terminals of the photoelectric sensing element. In other words, the photogenerated charges of the photoelectric sensing element when not operating prevent the original bias voltage of the photoelectric sensing element from being reduced, thereby preventing the original bias voltage of the first and second electrode terminals of the photoelectric sensing element from being insufficient when the photoelectric sensing element starts operating, and further preventing the reduction of the EQE of the photoelectric sensing element due to the insufficient original bias voltage, thereby ensuring that the photoelectric sensing element remains in an optimal state before operation.

[0081] In a second aspect, an embodiment of the present disclosure further provides a display device, comprising the photoelectric sensing substrate in the above embodiment.

[0082] By adopting the photoelectric sensing substrate in the above embodiment, touch control of the display device by touch objects such as fingerprints can be achieved, thereby achieving effective sensing of touch objects such as fingerprints by the display device and improving the photoelectric sensing effect of the display device.

[0083] The display device provided in the embodiments of the present disclosure may be any product or component with a display function, such as an OLED panel, an OLED TV, an OLED billboard, a display, a mobile phone, or a navigation device.

[0084] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A photoelectric sensing substrate, comprising a base, The sensing circuit and the photoelectric sensing element are sequentially stacked on one side of the substrate; The sensing circuit includes a scan line, a read line, a ground line and a first transistor; The first transistor includes a first gate, a first electrode and a second electrode; The photoelectric sensing element includes a first electrode, an organic photoelectric conversion layer, and a second electrode, wherein the first electrode, the organic photoelectric conversion layer, and the second electrode are stacked in sequence in a direction away from the substrate; It is characterized by: The sensing circuit further includes a second transistor, wherein the second transistor includes a second gate, a third electrode, and a fourth electrode; The first gate and the second gate are electrically connected to the scan line; the first electrode and the third electrode are electrically connected to the first electrode; the second electrode is electrically connected to the read line; and the fourth electrode is electrically connected to the ground line. The first transistor can be turned on when the photoelectric sensing element is working, and the second transistor can be turned on when the photoelectric sensing element is not working.

2. The photoelectric sensing substrate according to claim 1, wherein: The first transistor includes a P-type transistor, and the second transistor includes an N-type transistor; Alternatively, the first transistor includes an N-type transistor, and the second transistor includes a P-type transistor.

3. The photoelectric sensing substrate according to claim 2, wherein: The first transistor includes a low-temperature polysilicon transistor, an oxide semiconductor transistor, an amorphous silicon transistor or a field-effect transistor; The second transistor includes a low-temperature polysilicon transistor, an oxide semiconductor transistor, an amorphous silicon transistor, or a field-effect transistor.

4. The photoelectric sensing substrate according to any one of claims 1 to 3, wherein: There are multiple photoelectric sensing elements, and the multiple photoelectric sensing elements are arranged in an array; The scanning lines, the reading lines and the grounding lines each include a plurality of lines; One of the scanning lines is electrically connected to one row of the photoelectric sensing elements; One of the readout lines is electrically connected to a column of the photoelectric sensing elements; One of the ground lines is electrically connected to a column of the photoelectric sensing elements.

5. The photoelectric sensing substrate according to claim 1, wherein: The sensing circuit further includes at least one capacitor, The capacitor includes a first plate and a second plate. The first electrode plate is electrically connected to the first electrode, and the second electrode plate is electrically connected to the second electrode.

6. The photoelectric sensing substrate according to claim 1, wherein: The material of the organic photoelectric conversion layer includes PTAA or TPAFS-TMA; The material of the acceptor in the organic photoelectric conversion layer includes Y6, PC61BM or PC71BM; The material of the first electrode includes indium tin oxide or a stacked material of indium tin oxide, silver and indium tin oxide; The material of the second electrode includes aluminum.

7. The photoelectric sensing substrate according to claim 6, wherein: The thickness of the second electrode is in the range of 10 to 30 nm.

8. The photoelectric sensing substrate according to claim 3, wherein: The first gate of the low-temperature polysilicon transistor and the scanning line are arranged in the same layer, The second gate of the oxide semiconductor transistor is located on a side of the first gate away from the substrate, and an insulating layer is provided between the first gate and the second gate; A via hole is provided in the insulating layer, and the second gate is electrically connected to the scan line through the via hole.

9. A display device, characterized in that: The photoelectric sensing substrate comprises the photoelectric sensing substrate according to any one of claims 1 to 8.

10. A photoelectric sensing method for a photoelectric sensing substrate according to any one of claims 1 to 8, characterized in that: include: When the photoelectric sensing element is not working, the signal on the scanning line turns on the second transistor, and the electrical signal output by the photoelectric sensing element is grounded through the ground line; When the photoelectric sensing element is working, the signal on the scanning line turns on the first transistor, and the electrical signal output by the photoelectric sensing element is output through the reading line.

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