Phototransistor and display panel

Abstract

The invention discloses a photosensitive transistor and a display panel. The photo-transistor includes an active layer, a gate insulating layer, and a first transparent electrode layer. The active layer is arranged on the substrate, and a channel region is formed in the active layer. The gate insulating layer is arranged on the active layer and covers the channel region. The first transparent electrode layer is at least partially arranged on the gate insulating layer to form a gate of the photo-transistor, and the orthographic projection part of the channel region on the substrate falls into the orthographic projection of the gate on the substrate. Light to be detected irradiates the channel region through the first transparent electrode layer to form light sensing current. A channel region part located outside the orthographic projection of the grid electrode on the substrate can generate a potential well or a potential barrier under the bias voltage of the grid electrode, electron-hole pairs are excited after illumination so as to reduce the potential well or the potential barrier, and the light-sensitive current is further improved. The photosensitive transistor is manufactured by adopting a process compatible with the TFT-LCD, so that the photosensitive function of the TFT-LCD can be realized while the process efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of display devices, and more specifically, to a photosensitive transistor and a display panel. Background Art

[0002] The photosensitive component is an important component in the thin-film field effect transistor liquid crystal display (TFT-LCD). The photosensitive component can generate a corresponding photosensitive current according to the intensity of the received light to identify the intensity of the light. TFT-LCD can adjust the display brightness according to the intensity of the light, and TFT-LCD can also realize the fingerprint recognition function according to the intensity of the identified light.

[0003] In the related art, if a photodiode is used as a photosensitive component, it is not easy to integrate it on a TFT-LCD due to the difference in manufacturing process from TFT-LCD, and the manufacturing cost is high. If a photosensitive TFT is manufactured using a manufacturing process compatible with TFT-LCD, although the manufacturing efficiency can be improved, the photocurrent generated by the existing photosensitive TFT light-sensing recognition is small, and the recognition accuracy of light intensity is poor, making it difficult to realize the light-sensing function of TFT-LCD. Summary of the invention

[0004] Embodiments of the present invention provide a photosensitive transistor and a display panel.

[0005] The photosensitive transistor provided in the embodiment of the present invention comprises an active layer, a gate insulating layer and a first transparent electrode layer. The active layer is arranged on the substrate, and the active layer forms a channel region. The gate insulating layer is arranged on the active layer and covers the channel region. The first transparent electrode layer is at least partially arranged on the gate insulating layer to form a gate of the photosensitive transistor, and the orthographic projection of the channel region on the substrate partially falls within the orthographic projection of the gate on the substrate.

[0006] The light to be measured is irradiated on the channel region through the first transparent electrode layer to form a light-sensitive current. Due to the use of photosensitive transistors and TFT-LCD processes, the process efficiency can be improved.

[0007] In addition, the portion of the channel region outside the orthographic projection of the gate on the substrate corresponds to the uncontrollable region of the gate voltage. The uncontrollable region of the channel region can generate a potential well or potential barrier under the gate bias. The uncontrollable region of the channel region excites electron-hole pairs after light exposure to reduce the potential well or potential barrier, increasing the drift speed of electrons and holes between the source region and the drain region, and further increasing the light-sensitive current.

[0008] In this way, the light-sensing efficiency of the photosensitive transistor is improved by improving the photosensitive transistor. The photosensitive TFT can be manufactured using a process compatible with TFT-LCD. While improving the process efficiency, it also ensures that the photosensitive TFT has a sufficiently high accuracy in identifying the intensity of light, thus realizing the light-sensing function of TFT-LCD.

[0009] In some embodiments, the orthographic projection of the gate on the substrate falls within the orthographic projection of the channel region on the substrate, or the orthographic projection of the gate on the substrate is partially located outside the orthographic projection of the channel region on the substrate.

[0010] The uncontrollable area of ​​the channel region can be set according to the size parameter requirements of the phototransistor and the photosensitivity efficiency requirements of the phototransistor. The orthographic projection of the channel region on the substrate and the orthographic projection of the gate region on the substrate only need to have areas that do not overlap with each other.

[0011] In certain embodiments, an orthographic projection of the channel region on the substrate falls within an orthographic projection of the first transparent electrode layer on the substrate.

[0012] In some embodiments, the orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer on the substrate. The orthographic projection of the channel region on the substrate is outside the orthographic projection of the first transparent electrode layer on the substrate.

[0013] The orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer on the substrate, and the light to be measured can irradiate every part of the channel region through the first transparent electrode layer, which is beneficial to improving the light-sensitive current generated by the phototransistor.

[0014] The longer the area where the light to be measured can irradiate the channel region through the first transparent electrode layer, the greater the light-sensitive current generated by the phototransistor. The area where the light to be measured can irradiate the channel region through the first transparent electrode layer can be set according to the size parameter requirements of the phototransistor and the photosensitivity efficiency requirements of the phototransistor.

[0015] In some embodiments, the photosensitive transistor further includes a composite insulating layer located above the gate insulating layer, the composite insulating layer being formed with a first hollow groove. The first transparent electrode layer covers the composite insulating layer and the first hollow groove, and a portion of the first transparent electrode layer located at the bottom of the first hollow groove forms the gate. The orthographic projection of the channel region on the substrate falls within the orthographic projection of the bottom of the first hollow groove on the substrate.

[0016] The first hollow groove formed above the gate insulating layer can increase the light intensity of the light to be measured irradiating the channel region, thereby increasing the light-sensitive current generated by the phototransistor.

[0017] In some embodiments, the photosensitive transistor further includes a composite insulating layer located above the gate insulating layer, the composite insulating layer being formed with a plurality of second hollow grooves. The first transparent electrode layer covers the composite insulating layer and the plurality of second hollow grooves, and a portion of the first transparent electrode layer located at the bottom of the plurality of second hollow grooves forms the plurality of gates. The orthographic projection of the channel region on the substrate falls within the orthographic projection of the bottom of the second hollow groove on the substrate.

[0018] The first transparent electrode layer is segmented to cover multiple regions on the gate insulating layer, and each region covered by the first transparent electrode layer on the gate insulating layer can form a gate, so that multiple gates of the phototransistor can be formed. By adjusting the multiple gate voltages of the phototransistor, the phototransistor can detect photocurrents of different bands.

[0019] In some embodiments, the active layer includes a source region and a drain region located at both ends of the channel region. The phototransistor further includes an intermediate insulating layer, a metal layer and a second transparent electrode layer. The intermediate insulating layer is disposed on the gate insulating layer. The intermediate insulating layer is formed with two third hollow grooves, and at least a portion of the source region and the drain region are exposed from the at least two third hollow grooves, respectively. The metal layer covers the active layer and the two third hollow grooves to be connected to the source region and the drain region, thereby forming the source of the phototransistor and the drain of the phototransistor. The second transparent electrode layer is disposed on the intermediate insulating layer and is electrically connected to the metal layer.

[0020] The active region includes a channel region and source / drain regions located at opposite sides of the channel region. The metal layer is arranged on the active region to form a source electrode and / or a drain electrode of the photosensitive transistor.

[0021] In some embodiments, the photosensitive transistor further comprises a light shielding layer, wherein the light shielding layer is disposed between the active layer and the substrate. The orthographic projection of the channel region on the substrate is disposed inside the orthographic projection of the light shielding layer on the substrate.

[0022] The light shielding layer can be made of metal material, and can play a light shielding effect to prevent the active layer from receiving light from the back of the substrate, thereby affecting the detection of the light to be measured.

[0023] In some embodiments, the photosensitive transistor further includes a buffer layer disposed between the active layer and the substrate.

[0024] Defects in the substrate can easily capture carriers and thus affect the threshold voltage of the phototransistor. The buffer layer is used to block defects from the substrate, and can block the defects under the substrate to prevent the defects in the substrate from affecting the threshold voltage of the phototransistor.

[0025] An embodiment of the present invention provides a display panel, the display panel comprising a photosensitive transistor of any one of the above embodiments and a substrate. A display area and a non-display area are defined on the substrate, and the photosensitive transistor is arranged on the non-display area.

[0026] The photosensitive transistor 100 may be a TFT transistor disposed on the driving circuit layer. By improving the photosensitive transistor 100, the light-sensing efficiency of the photosensitive transistor 100 is improved, so that the TFT transistor on the non-display area of ​​the display panel has a light-sensing function.

[0027] In some embodiments, the display panel further includes a pixel electrode and a common electrode, the pixel electrode and the common electrode are arranged on the display area, the first transparent electrode layer and the pixel electrode are arranged on the same layer, or the first transparent electrode layer and the common electrode are arranged on the same layer.

[0028] The first transparent electrode layer and the pixel electrode are arranged in the same layer, or the first transparent electrode layer and the common electrode are arranged in the same layer, which can improve the process efficiency of the display panel.

[0029] In some embodiments, the drain of the phototransistor is connected to a drain signal line, and the drain signal line is used to provide a drain drive voltage to the drain of the phototransistor. The gate of the phototransistor is connected to a gate signal line, and the gate signal line is used to provide a gate drive voltage to the gate of the phototransistor. The detection circuit is used to detect the output current of the phototransistor.

[0030] The drain signal line can increase the drain voltage Vd of the phototransistor, and the gate signal line can provide a gate drive voltage Vg to the gate of the phototransistor. The intensity of the light to be measured can be detected according to the magnitude of the drain voltage Vd, the magnitude of the gate drive voltage Vg and the output current Itest of the phototransistor.

[0031] In some embodiments, the display panel further comprises a switching transistor. The source of the switching transistor is connected to a source signal line, and the source signal line is used to provide a source driving voltage to the source of the switching transistor. The gate of the switching transistor is connected to the gate signal line, and the gate signal line is used to provide a gate driving voltage to the gate of the switching transistor. The drain of the switching transistor is connected to the source of the photosensitive transistor. The detection circuit is used to detect the source voltage of the photosensitive transistor.

[0032] The switch transistor and the photosensitive transistor are connected in series for voltage division. When receiving the light to be measured, the light intensity of the light to be measured can be determined according to the voltage of the series voltage division.

[0033] In some embodiments, the phototransistor includes a plurality of gates, and the gate signal line is used to provide a gate driving voltage to each gate of the phototransistor in a time-sharing manner.

[0034] The voltage applied to different gates of the phototransistor can be adjusted in a time-sharing manner to detect photocurrents in different bands in a time-sharing manner.

[0035] By improving the photosensitive transistor, the light-sensing efficiency of the photosensitive transistor is improved. The TFT transistor on the non-display area has a light-sensing function. The photosensitive TFT can be manufactured using a process compatible with TFT-LCD. While improving the process efficiency, it also ensures that the photosensitive TFT has a high enough accuracy in identifying the light intensity, thus realizing the light-sensing function of TFT-LCD.

[0036] The embodiment of the present invention is a photosensitive transistor and a display panel. The photosensitive transistor includes an active layer, a gate insulating layer and a first transparent electrode layer. The active layer is arranged on a substrate, and a channel region is formed in the active layer. The gate insulating layer is arranged on the active layer and covers the channel region. The first transparent electrode layer is at least partially arranged on the gate insulating layer to form a gate of the photosensitive transistor, and the positive projection of the channel region on the substrate falls within the positive projection of the gate on the substrate. The light to be measured is irradiated on the channel region through the first transparent electrode layer to form a photosensitive current. The portion of the channel region located outside the positive projection of the gate on the substrate corresponds to an uncontrollable region of the gate voltage. The uncontrollable region of the channel region can generate a potential well or a potential barrier under the gate bias. After being irradiated with light, the uncontrollable region of the channel region excites electron-hole pairs to reduce the potential well or potential barrier, increases the drift velocity of electrons and holes between the source region and the drain region, and further improves the photosensitive current. By improving the photosensitive transistor, the photosensitivity efficiency of the photosensitive transistor is improved. The photosensitive TFT is manufactured using a process compatible with TFT-LCD. While improving the process efficiency, it also ensures that the photosensitive TFT has a sufficiently high accuracy in identifying the intensity of light, thus realizing the photosensitivity function of TFT-LCD.

[0037] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0039] Figure 1 is a cross-sectional view of a phototransistor according to a first embodiment of the present invention;

[0040] Figure 2 is a top view of a phototransistor according to a first embodiment of the present invention;

[0041] Figure 3 is a cross-sectional view of a phototransistor according to a second embodiment of the present invention;

[0042] Figure 4 is a top view of a phototransistor according to a second embodiment of the present invention;

[0043] Figure 5 is a top view of a phototransistor according to a third embodiment of the present invention;

[0044] Figure 6 is a schematic diagram of a gate of a phototransistor according to a third embodiment of the present invention;

[0045] Figure 7 is a cross-sectional view of a phototransistor according to a fourth embodiment of the present invention;

[0046] Figure 8 It is a schematic diagram of the connection between the phototransistor and the detection circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The embodiments of the present invention are described in detail below, and the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0048] The photosensitive component is an important component in the thin-film field effect transistor liquid crystal display (TFT-LCD). The photosensitive component can generate a corresponding photosensitive current according to the intensity of the received light to identify the intensity of the light. TFT-LCD can adjust the display brightness according to the intensity of the light, and TFT-LCD can also realize the fingerprint recognition function according to the intensity of the identified light.

[0049] In the related art, if a photodiode is used as a photosensitive component, it is not easy to integrate it on a TFT-LCD due to the difference in manufacturing process from TFT-LCD, and the manufacturing cost is high. If a photosensitive TFT is manufactured using a manufacturing process compatible with TFT-LCD, although the manufacturing efficiency can be improved, the photocurrent generated by the existing photosensitive TFT light-sensing recognition is small, and the recognition accuracy of light intensity is poor, making it difficult to realize the light-sensing function of TFT-LCD.

[0050] Reference Figure 1The embodiment of the present invention provides a phototransistor 100, comprising an active layer 10, a gate insulating layer 20 and a first transparent electrode layer 30. The active layer 10 is disposed on a substrate, and a channel region is formed in the active layer 10. The gate insulating layer 20 is disposed on the active layer 10 and covers the channel region. The first transparent electrode layer is at least partially disposed on the gate insulating layer 20 to form a gate 31 of the phototransistor 100, and the orthographic projection of the channel region on the substrate partially falls within the orthographic projection of the gate 31 on the substrate.

[0051] The light to be measured is irradiated on the channel region through the first transparent electrode layer 30 to form a light-sensitive current. Since the photosensitive transistor 100 and the TFT-LCD process are used, the process efficiency can be improved.

[0052] In addition, the portion of the channel region outside the orthographic projection of the gate 31 on the substrate corresponds to the uncontrollable region of the gate voltage. The uncontrollable region of the channel region can generate a potential well or potential barrier under the bias of the gate 31. The uncontrollable region of the channel region excites electron-hole pairs after light exposure to reduce the potential well or potential barrier, increases the drift speed of electrons and holes between the source region and the drain region, and further increases the light-sensitive current.

[0053] Thus, by improving the phototransistor 100, the light-sensing efficiency of the phototransistor 100 is improved. The photosensitive TFT can be manufactured using a process compatible with TFT-LCD, which improves the process efficiency while ensuring that the photosensitive TFT has a sufficiently high accuracy in identifying the light intensity, thereby realizing the light-sensing function of TFT-LCD.

[0054] Specifically, the active layer 10 can be made of one of amorphous silicon (α-Si), oxide (Oxide) or low temperature polysilicon (LTPS), or other materials. The active layer 10 can be composed of different doped materials, wherein the region with higher doping concentration is called n-type region or p-type region, which is used to provide charge carriers. The region with lower doping concentration is called i-type region, which is used to limit the diffusion of charge carriers. The function of the active layer 10 is to excite electrons or holes to a high energy state, thereby achieving current control and amplification.

[0055] The active layer 10 includes a channel region and a source region and a drain region located on opposite sides of the channel region, and the source region and the drain region can provide electrons and holes. When a voltage is applied to the gate 31 of the phototransistor 100, the source region and the drain region drift electrons and holes through the channel region, so that the phototransistor 100 generates current.

[0056] The gate insulating layer 20 may be made of inorganic insulating materials such as silicon oxide, silicon nitride or silicon oxynitride, and the active layer 10 may be made of materials such as polysilicon and metal oxide.

[0057] The first transparent electrode layer 30 has high light transparency and conductivity, and can be made of materials such as zinc oxide, tin oxide, indium tin oxide, etc. The first transparent electrode layer 30 is at least partially disposed on the gate insulating layer 20 to form a gate 31 of the phototransistor 100.

[0058] The photosensitive transistor 100 can be obtained by a top-gate transistor. Figure 1 as well as Figure 2 , N-gate may be the original gate of the transistor with a top gate structure. After N-gate is etched, the first transparent electrode layer 30 covers the position of N-gate to form a new gate 31.

[0059] The photosensitive transistor 100 can be obtained by a bottom-gate structure transistor. Figure 3 as well as Figure 4 , Gate can be the original gate of the transistor with a bottom gate structure, and the first transparent electrode layer 30 covers the gate insulating layer 20 to form a new gate 31. The original gate Gate of the phototransistor 100 is no longer connected to the gate voltage, and can be used as a metal shielding layer set on the back of the active area to prevent the ambient light on the back of the active area from affecting the active area.

[0060] The light to be measured can be irradiated on the channel region through the first transparent electrode layer 30 and the gate insulating layer 20. The energy of the photons of the light to be measured is transferred to the carriers in the channel region, generating photogenerated carriers, i.e., photogenerated electron-hole pairs, which are beneficial to the drift of electrons and holes between the source region and the drain region, and improve the light-sensitive current of the phototransistor 100.

[0061] The orthographic projection of the channel region on the substrate partially falls inside the orthographic projection of the gate 31 on the substrate, and partially lies outside the orthographic projection of the gate 31 on the substrate. The portion of the channel region that falls inside the orthographic projection of the gate 31 on the substrate corresponds to the control region of the gate voltage, and the portion of the channel region that lies outside the orthographic projection of the gate 31 on the substrate corresponds to the uncontrollable region of the gate voltage.

[0062] The uncontrollable area of ​​the channel region can generate a potential well or potential barrier under the bias of the gate 31. The uncontrollable area of ​​the channel region excites electron-hole pairs after light exposure to reduce the potential well or potential barrier, increase the drift speed of electrons and holes between the source region and the drain region, and further improve the light-sensitive current of the phototransistor 100.

[0063] Thus, by improving the phototransistor 100, the light-sensing efficiency of the phototransistor 100 is improved. The photosensitive TFT can be manufactured using a process compatible with TFT-LCD, which improves the process efficiency while ensuring that the photosensitive TFT has a sufficiently high accuracy in identifying the light intensity, thereby realizing the light-sensing function of TFT-LCD.

[0064] In some embodiments, the orthographic projection of the gate 31 on the substrate falls within the orthographic projection of the channel region on the substrate, or the orthographic projection of the gate 31 on the substrate is partially located outside the orthographic projection of the channel region on the substrate.

[0065] The orthographic projection of the channel region on the substrate and the orthographic projection of the gate 31 region on the substrate only need to have areas that do not overlap with each other, and the specific positions of the non-overlapping areas are not limited.

[0066] Specifically, the orthographic projection of the gate 31 on the substrate completely falls within the orthographic projection of the channel region on the substrate. The orthographic projection of the gate 31 on the substrate may also partially fall within the orthographic projection of the channel region on the substrate, and partially be located outside the orthographic projection of the channel region on the substrate. Among them, the area where the orthographic projection of the gate 31 on the substrate overlaps with the orthographic projection on the substrate is the controllable area of ​​the channel region, and the area where the orthographic projection of the gate 31 on the substrate does not overlap with the orthographic projection on the substrate is the uncontrollable area of ​​the channel region.

[0067] The longer the uncontrollable area of ​​the channel region is, the greater the amount of photogenerated carriers generated by the light to be measured under the same lighting conditions will be, the more obvious the difference between the light-sensitive current, i.e., the illumination current and the dark current will be (the larger the ratio), and the greater the photosensitivity efficiency of the phototransistor 100 will be.

[0068] The uncontrollable area of ​​the channel region can be increased by changing the position of the gate 31 and reducing the width of the gate 31 . The uncontrollable area of ​​the channel region can be increased by increasing the position of the channel region and the length of the channel region, thereby improving the photosensitivity of the phototransistor 100 .

[0069] However, the size parameters of the phototransistor 100 are limited, and the uncontrollable area of ​​the channel region can be set according to the size parameter requirements of the phototransistor 100 and the photosensitivity requirements of the phototransistor 100. The orthographic projection of the channel region on the substrate and the orthographic projection of the gate 31 region on the substrate only need to have areas that do not overlap with each other.

[0070] Reference Figure 2 as well as Figure 4 In some embodiments, the orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer 30 on the substrate. The orthographic projection of the channel region on the substrate is located outside the orthographic projection of the first transparent electrode layer 30 on the substrate.

[0071] Specifically, the area where the light to be measured irradiates the channel region through the first transparent electrode layer 30 can be increased by increasing and changing the position of the channel region and the length of the channel region. The area where the light to be measured irradiates the channel region through the first transparent electrode layer 30 can be increased by increasing and changing the position of the first transparent electrode layer 30 and the length of the first transparent electrode layer 30.

[0072] However, the size parameters of the phototransistor 100 are limited, and the area where the light to be measured irradiates the channel region through the first transparent electrode layer 30 can be set in accordance with the size parameter requirements of the phototransistor 100 and the photosensitivity requirements of the phototransistor 100.

[0073] Reference Figure 5 In some embodiments, the orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer 30 on the substrate.

[0074] Specifically, the longer the area where the light to be measured can irradiate the channel region through the first transparent electrode layer 30, the more energy of the photons of the light to be measured is transferred to the carriers in the channel region, the more conducive it is to the drift of electrons and holes between the source region and the drain region, and the greater the photosensitivity current generated by the phototransistor 100.

[0075] The orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer 30 on the substrate, and the light to be measured can be irradiated to every part of the channel region through the first transparent electrode layer 30, which is beneficial to improving the light-sensitive current generated by the phototransistor 100.

[0076] Reference Figure 1 In some embodiments, the photosensitive transistor 100 further includes a composite insulating layer 40 located above the gate insulating layer 20, and the composite insulating layer 40 is formed with a first hollow groove. The first transparent electrode layer 30 covers the composite insulating layer 40 and the first hollow groove, and the portion of the first transparent electrode layer 30 located at the bottom of the first hollow groove forms a gate 31. The orthographic projection of the channel region on the substrate falls within the orthographic projection of the bottom of the first hollow groove on the substrate.

[0077] Specifically, the composite insulating layer 40 includes a plurality of sub-layers, each of which may be made of a different insulating material. At least a portion of the plurality of sub-layers is disposed between the active layer 10 and the first transparent electrode layer.

[0078] A first hollow groove is formed above the gate insulating layer 20, and the first hollow groove is covered with a first transparent electrode layer 30. External light to be measured can be irradiated to the channel area through the first hollow groove, and the light-guiding medium of the external light to be measured is air. External light to be measured can also be irradiated to the channel area through the first transparent electrode layer 30, and the light-guiding medium of the external light to be measured is the first transparent electrode layer 30.

[0079] Since air is a transparent medium, the light to be measured maintains its original speed and direction when propagating in the air, and the light guiding effect of air is better than that of the first transparent electrode layer 30 as a light guiding medium. Therefore, the first hollow groove formed above the gate insulating layer 20 can increase the light intensity of the light to be measured irradiating the channel region, thereby increasing the light-sensitive current generated by the phototransistor 100.

[0080] Reference Figure 5 as well as Figure 6 In some embodiments, the photosensitive transistor 100 further includes a composite insulating layer 40 located above the gate insulating layer 20, and the composite insulating layer 40 is formed with a plurality of second hollow grooves. The first transparent electrode layer 30 covers the composite insulating layer 40 and the plurality of second hollow grooves, and the portion of the first transparent electrode layer 30 located at the bottom of the plurality of second hollow grooves forms a plurality of gates 31. The orthographic projection of the channel region on the substrate falls within the orthographic projection of the bottom of the second hollow groove on the substrate.

[0081] The first transparent electrode layer 30 covers multiple regions on the gate insulating layer 20 in sections, and each region where the first transparent electrode layer 30 covers the gate insulating layer 20 can form a gate 31, so that multiple gates 31 of the phototransistor 100 can be formed. By adjusting the multiple gate voltages of the phototransistor 100, the phototransistor 100 can detect photocurrents of different wavelength bands.

[0082] Specifically, a plurality of second hollow grooves are formed above the gate insulating layer 20 , and each of the second hollow grooves is covered with the first transparent electrode layer 30 to form a gate 31 .

[0083] When a voltage is applied to each gate 31, a corresponding current channel can be established to form a current, so that electrons can transition from one energy level to another, generating a corresponding energy level segment. By adjusting the voltage applied to the gate 31, the corresponding energy level segment can be adjusted to achieve photocurrent detection of a corresponding band.

[0084] Reference Figure 1 In some embodiments, the active layer 10 includes a source region and a drain region located at both ends of the channel region. The phototransistor 100 also includes an intermediate insulating layer 50, a metal layer 60, and a third transparent electrode layer. The intermediate insulating layer 50 is disposed on the gate insulating layer 20. The intermediate insulating layer 50 is formed with two third hollow grooves, and at least part of the source region and the drain region are exposed from at least two third hollow grooves, respectively. The metal layer 60 covers the active layer 10 and the two third hollow grooves to be connected to the source region and the drain region, thereby forming the source of the phototransistor 100 and the drain of the phototransistor 100. The third transparent electrode layer is disposed on the intermediate insulating layer 50 and is electrically connected to the metal layer 60.

[0085] Specifically, the intermediate insulating layer 50 may include a plurality of sub-layers, each of which may be made of a different insulating material. At least a portion of the plurality of sub-layers is disposed on the gate insulating layer 20 .

[0086] The active region includes a channel region and source / drain regions located at opposite sides of the channel region. The metal layer 60 is disposed on the active region to form a source of the phototransistor 100 and / or a drain of the phototransistor 100 .

[0087] In a TFT transistor made of amorphous silicon and oxide materials, the second transparent electrode layer can be arranged on the same layer as the metal layer 60, and the pixel electrode provides the pixel voltage to the gate 31 and the drain of the TFT through the second transparent electrode layer. In a TFT transistor made of low-temperature polysilicon material, since the gate insulating layer 20 is arranged relatively thick, the second transparent layer is not arranged on the same layer as the metal layer 60, and the first transparent electrode layer 30 and the second transparent electrode layer can both serve as the gate 31 of the TFT transistor.

[0088] It should be noted that the second transparent electrode layer and the metal layer 60 can be arranged on the same layer, that is, the second transparent electrode layer and the metal layer 60 can be formed by the same preparation process, thereby simplifying the preparation process of the display substrate.

[0089] Reference Figure 1 In some embodiments, the photosensitive transistor 100 further includes a light shielding layer 70, which is disposed between the active layer 10 and the substrate. The orthographic projection of the channel region on the substrate is disposed inside the orthographic projection of the light shielding layer 70 on the substrate.

[0090] Specifically, the light shielding layer 70 can be made of metal material. The light shielding layer 70 can play a light shielding effect to prevent the active layer 10 from receiving light from the back side of the substrate, thereby affecting the detection of the light to be measured.

[0091] The photosensitive transistor 100 can be obtained by a bottom-gate structure transistor, and the bottom gate of the bottom-gate structure transistor can be used as the light shielding layer 70. Figure 3 as well as Figure 4 , Gate can be the original gate of the transistor with a bottom gate structure, and the first transparent electrode layer 30 covers the gate insulating layer 20 to form a new gate 31. The original gate Gate of the phototransistor 100 is no longer connected to the gate voltage, and can be used as a light shielding layer 70 to prevent the ambient light on the back of the active area from affecting the active area.

[0092] Reference Figure 1 In some embodiments, the photosensitive transistor 100 further includes a buffer layer 80 , which is disposed between the active layer 10 and the substrate.

[0093] Specifically, defects in the substrate can easily capture carriers and thus affect the threshold voltage of the phototransistor 100. The buffer layer 80 is used to block defects from the substrate and can block the defects under the substrate to prevent the defects in the substrate from affecting the threshold voltage of the phototransistor 100.

[0094] Furthermore, the orthographic projection of the buffer layer 80 on the substrate can completely cover the orthographic projection of the active region on the substrate, thereby preventing defects of the substrate from affecting the active region.

[0095] Reference Figure 7 The photosensitive transistor 100 may include a combination of multiple TFT transistors, each of which has a different light-sensitive wavelength range, and any combination of two or three can be used to detect light of different wavelengths.

[0096] Furthermore, since α-Si, Oxide and LTPS TFT transistors have different light-sensitive wavelength ranges, any combination of two or three of the α-Si, Oxide and LTPS TFT transistors can be used to detect light of different wavelengths.

[0097] An embodiment of the present invention provides a display panel, which includes a photosensitive transistor 100 of any one of the above embodiments and a substrate. A non-display area and a display area are defined on the substrate. A display area and a non-display area are defined on the substrate, and the photosensitive transistor 100 is disposed on the non-display area.

[0098] Further, the pixel circuit layer is arranged on the display area, and the pixel circuit layer may be provided with a pixel unit. The driving circuit layer is arranged on the non-display area, and the driving circuit layer may be provided with a gate driving circuit, and the gate driving circuit is used to provide a driving voltage to the pixel unit, and the photosensitive transistor may be arranged on the driving circuit layer.

[0099] Specifically, the photosensitive transistor 100 may be a TFT transistor disposed on the driving circuit layer. By improving the photosensitive transistor 100, the light-sensing efficiency of the photosensitive transistor 100 is improved. The TFT transistor on the non-display area of ​​the display panel has a light-sensing function. Therefore, a process compatible with TFT-LCD can be used to manufacture the photosensitive TFT, which improves the process efficiency of the display panel and ensures that the photosensitive TFT has a sufficiently high accuracy in identifying the light intensity, thereby realizing the light-sensing function of the TFT-LCD.

[0100] In some embodiments, the display panel further includes a pixel electrode and a common electrode, the pixel electrode and the common electrode are arranged on the display area, the first transparent electrode layer is arranged on the same layer as the pixel electrode, or the first transparent electrode layer is arranged on the same layer as the common electrode.

[0101] The first transparent electrode layer and the pixel electrode are arranged in the same layer, or the first transparent electrode layer and the common electrode are arranged in the same layer, which can improve the process efficiency of the display panel.

[0102] Specifically, the same-layer arrangement means that two layers, parts, components, elements or parts can be formed by the same manufacturing process, and the two layers, parts, components, elements or parts can be formed of the same material.

[0103] The first transparent conductive layer arranged on the non-display area can be arranged on the same layer as the pixel electrode arranged on the display area, that is, the first transparent conductive layer on the non-display area and the pixel electrode on the display area can be formed using the same material layer and the same preparation process, thereby simplifying the preparation process of the display substrate.

[0104] The first transparent conductive layer arranged on the non-display area can be arranged on the same layer as the common electrode arranged on the display area, that is, the first transparent conductive layer on the non-display area and the common electrode on the display area can be formed using the same material layer and the same preparation process, thereby simplifying the preparation process of the display substrate.

[0105] Reference Figure 8 The display panel further includes a detection circuit 300. The drain of the phototransistor 100 is connected to the drain signal line 210, and the drain signal line 210 is used to provide a drain driving voltage to the drain of the phototransistor 100. The gate 31 of the phototransistor 100 is connected to the gate signal line 220, and the gate signal line 220 is used to provide a gate driving voltage to the gate 31 of the phototransistor 100. The detection circuit 300 is used to detect the output current of the phototransistor 100.

[0106] Specifically, the drain signal line 210 can increase the drain voltage Vd of the phototransistor 100, and the gate signal line 220 can provide a gate drive voltage Vg to the gate 31 of the phototransistor 100. According to the magnitude of the drain voltage Vd, the magnitude of the gate drive voltage Vg and the output current Itest of the phototransistor 100, the intensity of the light to be measured can be detected.

[0107] Further, the phototransistor 100 can be placed in a dark environment, and the dark state current of the output current of the phototransistor 100 is obtained as Itest1. When the phototransistor 100 is placed in an environment irradiated with the light to be measured, the output current of the phototransistor 100 is obtained as Itest2. At this time, the photocurrent generated by the phototransistor 100 is Itest2-Itest1. According to the photocurrent Itest2-Itest1 generated by the phototransistor 100, the voltage Vg applied to the gate 31 of the phototransistor 100 and the voltage Vd applied to the drain of the phototransistor 100 can determine the intensity of the light to be measured.

[0108] The phototransistor 100 can also be placed in an environment where light is irradiated to be measured, and the effect of light temperature rise on the phototransistor 100 can be accumulated, and the temperature-sensitive current Itest3 can be obtained when the voltage applied to the gate 31 is Vg1. The light-sensitive current Itest4 can be obtained when the voltage applied to the gate 31 is Vg2. The temperature-sensitive current Itest3 and the light-sensitive current Itest4 can be corrected to determine a more accurate photocurrent.

[0109] Reference Figure 8 In some embodiments, the display panel further includes a switching transistor 400. The source of the switching transistor 400 is connected to the source signal line 230, and the source signal line 230 is used to provide a source driving voltage to the source of the switching transistor 400. The gate 31 of the switching transistor 400 is connected to the gate signal line 220, and the gate signal line 220 is used to provide a gate driving voltage to the gate 31 of the switching transistor 400. The drain of the switching transistor 400 is connected to the source of the phototransistor 100. The detection circuit 300 is used to detect the source voltage of the phototransistor 100.

[0110] Specifically, the source signal line 230 is used to provide a source driving voltage Vs to the source of the switch transistor 400. The switch transistor 400 and the phototransistor 100 are connected in series for voltage division, and when receiving the light to be measured, the light intensity of the light to be measured can be determined according to the voltage Vtest of the series voltage division.

[0111] Furthermore, the switch transistor 400 may be the phototransistor 100 or other transistors.

[0112] In some embodiments, the phototransistor 100 includes a plurality of gates 31. The gate signal line 220 is used to provide a gate driving voltage to each gate 31 of the phototransistor 100 in a time-sharing manner.

[0113] The voltages applied to different gates 31 of the phototransistor 100 can be adjusted in a time-sharing manner to detect photocurrents in different wavelength bands in a time-sharing manner.

[0114] Specifically, by adjusting the voltages applied to different gates 31 of the phototransistor 100 in time-sharing mode, photoelectric sensing of the ultraviolet band can be achieved, thereby realizing the measurement of the sun protection factor. By adjusting the voltages applied to different gates 31 of the phototransistor 100 in time-sharing mode, sensing of the infrared band can also be realized, thereby realizing distance detection. By adjusting the voltages applied to different gates 31 of the phototransistor 100 in time-sharing mode, sensing of visible light can also be realized, thereby realizing automatic adjustment of screen brightness.

[0115] The embodiment of the present invention is a photosensitive transistor 100 and a display panel. The photosensitive transistor 100 includes an active layer 10, a gate insulating layer 20 and a first transparent electrode layer 30. The active layer 10 is arranged on a substrate, and a channel region is formed in the active layer 10. The gate insulating layer 20 is arranged on the active layer 10 and covers the channel region. The first transparent electrode layer is at least partially arranged on the gate insulating layer 20 to form a gate 31 of the photosensitive transistor 100, and the orthographic projection of the channel region on the substrate falls within the orthographic projection of the gate 31 on the substrate. The light to be measured is irradiated on the channel region through the first transparent electrode layer to form a photosensitive current. The portion of the channel region located outside the orthographic projection of the gate 31 on the substrate corresponds to an uncontrollable region of the gate voltage. The uncontrollable region of the channel region can generate a potential well or a potential barrier under the bias of the gate 31. The uncontrollable region of the channel region excites electron-hole pairs after light exposure to reduce the potential well or potential barrier, increases the drift velocity of electrons and holes between the source region and the drain region, and further increases the photosensitive current. The improvement of the photosensitive transistor 100 improves the light-sensing efficiency of the photosensitive transistor 100. The photosensitive TFT is manufactured using a process compatible with TFT-LCD, which improves the process efficiency while ensuring that the photosensitive TFT has a sufficiently high accuracy in identifying the light intensity, thereby realizing the light-sensing function of TFT-LCD.

[0116] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0117] In addition, the term "connection" should be understood in a broad sense, for example, it can include fixed connection, detachable connection, or integral connection; it can include direct connection, indirect connection through an intermediate medium, and internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0118] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0119] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0120] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A photosensitive transistor, formed on a substrate, characterized in that: The photosensitive transistor comprises: an active layer, the active layer being disposed on the substrate and having a channel region formed therein; a gate insulating layer, the gate insulating layer being disposed on the active layer and covering the channel region; A first transparent electrode layer is at least partially disposed on the gate insulating layer to form a gate of the photosensitive transistor, and an orthographic projection of the channel region on the substrate partially falls within an orthographic projection of the gate on the substrate.

2. The phototransistor according to claim 1, characterized in that: The orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer on the substrate.

3. The phototransistor according to claim 1, characterized in that: The orthographic projection of the channel region on the substrate falls within the orthographic projection of the first transparent electrode layer on the substrate, and the orthographic projection of the channel region on the substrate is outside the orthographic projection of the first transparent electrode layer on the substrate.

4. The phototransistor according to claim 1, characterized in that: The photosensitive transistor also includes a composite insulating layer located above the gate insulating layer, the composite insulating layer is formed with a first hollow groove, the first transparent electrode layer covers the composite insulating layer and the first hollow groove, the portion of the first transparent electrode layer located at the bottom of the first hollow groove forms the gate, and the orthographic projection of the channel region on the substrate falls within the orthographic projection of the bottom of the first hollow groove on the substrate.

5. The phototransistor according to claim 1, characterized in that: The photosensitive transistor also includes a composite insulating layer located above the gate insulating layer, the composite insulating layer is formed with a plurality of second hollow grooves, the first transparent electrode layer covers the composite insulating layer and the plurality of second hollow grooves, the first transparent electrode layer is located at the bottom of the plurality of second hollow grooves to form the plurality of gates, and the orthographic projection of the channel region on the substrate falls within the orthographic projection of the bottom of the second hollow grooves on the substrate.

6. The phototransistor according to claim 1, characterized in that: The active layer includes a source region and a drain region located at two ends of the channel region, and the photosensitive transistor further includes: an intermediate insulating layer, the intermediate insulating layer being disposed on the gate insulating layer, the intermediate insulating layer being formed with two second hollow grooves, at least a portion of the source region and the drain region being exposed from the at least two second hollow grooves respectively; A metal layer, the metal layer covers the active layer and the two second hollow grooves to be connected to the source region and the drain region, thereby forming a source of the phototransistor and a drain of the phototransistor; A second transparent electrode layer is disposed on the intermediate insulating layer and is electrically connected to the metal layer.

7. The phototransistor according to claim 1, characterized in that: The photosensitive transistor further includes a light shielding layer, which is disposed between the active layer and the substrate, and an orthographic projection of the channel region on the substrate is disposed inside an orthographic projection of the light shielding layer on the substrate.

8. The phototransistor according to claim 1, characterized in that: The photosensitive transistor further includes a buffer layer disposed between the active layer and the substrate.

9. A display panel, characterized in that: The display panel comprises: A substrate, wherein a display area and a non-display area are defined on the substrate; The photosensitive transistor according to any one of claims 1 to 8, wherein the photosensitive transistor is arranged on the non-display area.

10. The display panel according to claim 9, characterized in that: The display panel further includes a pixel electrode and a common electrode. The pixel electrode and the common electrode are arranged on the display area. The first transparent electrode layer and the pixel electrode are arranged in the same layer, or the first transparent electrode layer and the common electrode are arranged in the same layer.

11. The display panel according to claim 9, characterized in that: The drain of the phototransistor is connected to a drain signal line, and the drain signal line is used to provide a drain driving voltage to the drain of the phototransistor. The gate of the phototransistor is connected to a gate signal line, and the gate signal line is used to provide a gate driving voltage to the gate of the phototransistor. The display panel also includes a switching transistor and a detection circuit, the source of the switching transistor is connected to a source signal line, the source signal line is used to provide a source drive voltage to the source of the switching transistor, the gate of the switching transistor is connected to the gate signal line, the gate signal line is used to provide a gate drive voltage to the gate of the switching transistor, the drain of the switching transistor is connected to the source of the phototransistor, the detection circuit is used to detect the output current of the phototransistor, and the detection circuit is also used to detect the source voltage of the phototransistor.

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