Light sensing device with biased gate electrode and light sensing panel using the same

Abstract

A light sensing device with a biased gate electrode and a light sensing panel used therein, the light sensing device comprises a substrate, a gate electrode, a shielding electrode, an insulating layer, a semiconductor layer, a source electrode and a drain electrode. The gate electrode and the shielding electrode are disposed on the substrate and are separated from each other. The insulating layer is disposed on the gate electrode and the shielding electrode. The semiconductor layer is disposed on the insulating layer. The source and drain electrodes are respectively connected to the semiconductor layer, wherein the semiconductor layer has a channel region between the source and drain electrodes, and the channel region is divided into a first region and a second region, wherein the first region is adjacent to the drain electrode and overlaps with the gate electrode, the second region is adjacent to the source electrode and does not overlap with the gate electrode, and the second region partially overlaps with the shielding electrode.

Description

Technical Field

[0001] The invention relates to a light sensing device with a biased gate electrode and an optical panel using the same. Background Art

[0002] Photoelectric sensors can convert light into current or voltage signals. Photoelectric sensors can be made in the form of thin film transistors and arranged in arrays for applications in optical touch, fingerprint recognition, X-ray detection, etc. Depending on the wavelength of light to be absorbed, the photoelectric sensor can include a semiconductor film with an appropriate band gap. Summary of the invention

[0003] According to some embodiments of the present invention, a light sensing device includes a substrate, a gate electrode, a shielding electrode, an insulating layer, a semiconductor layer, a first drain / source electrode, and a second source / drain electrode. The gate electrode is disposed on the substrate. The shielding electrode is disposed on the substrate and is separated from the gate electrode. The insulating layer is disposed on the gate electrode and the shielding electrode. The semiconductor layer is disposed on the insulating layer. The first drain / source electrode and the second source / drain electrode are respectively connected to the semiconductor layer, wherein the semiconductor layer has a channel region between the first drain / source electrode and the second source / drain electrode, and the channel region is divided into a first region and a second region, wherein the first region is adjacent to the first drain / source electrode and overlaps with the gate electrode, the second region is adjacent to the second source / drain electrode and does not overlap with the gate electrode, and the second region partially overlaps with the shielding electrode.

[0004] According to some embodiments of the present invention, the light sensing panel includes the aforementioned light sensing device, a scan line, a bias line, a sensing switch element, and a low potential line. The scan line and the bias line are disposed on the substrate. The sensing switch element is disposed on the substrate, wherein a control end of the sensing switch element is electrically connected to the scan line, and two ends of the sensing switch element are electrically connected to the bias line and the first drain / source electrode of the light sensing device, respectively. The low potential line is disposed on the substrate and electrically connected to the second source / drain electrode of the light sensing device.

[0005] According to some embodiments of the present invention, the light sensing panel includes the aforementioned light sensing device, a scan line, and a low potential line. The scan line is disposed on a substrate, wherein a gate electrode of the light sensing device is electrically connected to the scan line with a first drain / source electrode. The low potential line is disposed on a substrate, wherein a second source / drain electrode of the light sensing device is electrically connected to the low potential line. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In the following drawings, various features are not drawn in proportion to industry practice standards. In fact, the size of various features may be increased or reduced arbitrarily.

[0007] Figure 1A is a top view schematic diagram of a light sensing device according to some embodiments;

[0008] Figure 1B is along Figure 1A A schematic cross-sectional view of line 1B-1B;

[0009] Figure 2A is a top view schematic diagram of a light sensing device according to some embodiments;

[0010] Figure 2B is along Figure 2A A schematic cross-sectional view of line 2B-2B;

[0011] Figure 3A is a schematic top view of a light sensing panel according to some embodiments;

[0012] Figure 3B yes Figure 3A A schematic circuit diagram of a pixel unit of a light sensing panel;

[0013] Figure 3C yes Figure 3B A cross-sectional schematic diagram of a pixel unit;

[0014] Figure 3D yes Figure 3C A schematic top view of a light sensing device of a pixel unit;

[0015] Figure 4A is a schematic top view of a light sensing panel according to some embodiments;

[0016] Figure 4B yes Figure 4A A schematic circuit diagram of a pixel unit of a light sensing panel;

[0017] Figure 4C yes Figure 4B A cross-sectional schematic diagram of a pixel unit;

[0018] Figure 4D yes Figure 4C A schematic top view of a light sensing device of a pixel unit;

[0019] Figure 5A is a schematic top view of a light sensing panel according to some embodiments;

[0020] Figure 5B yes Figure 5A A partial cross-sectional schematic diagram of a light sensing display panel;

[0021] Figure 6 is a schematic top view of a light sensing panel according to some embodiments;

[0022] Figure 7is a schematic top view of a light sensing panel according to some embodiments;

[0023] Figure 8 is a top view of a light sensing panel according to some embodiments.

[0024]

Explanation of symbols

[0025] 100: Light sensing device

[0026] 100S: First End

[0027] 100D: Second end

[0028] 100G: Control side

[0029] 100P: Shield terminal

[0030] 110:Substrate

[0031] 122,126,128: Gate electrode

[0032] 124: Shielding electrode

[0033] 130: Insulation layer

[0034] 132: Insulation part

[0035] 142,144,146: Semiconductor layer

[0036] 142C: Channel area

[0037] 142CA: Switching area

[0038] 142CB: Photosensitive area

[0039] 152S, 154S, 156S: Source / Drain Electrodes

[0040] 152D, 154D, 156D: Drain / source electrodes

[0041] 200: Light sensor panel

[0042] 200': Light sensing display panel

[0043] 210: Sensing switch element

[0044] 210S: First End

[0045] 210D: Second end

[0046] 210G: Control terminal

[0047] 220: Display switch element

[0048] 220S: First End

[0049] 220D: Second end

[0050] 220G: Control terminal

[0051] 230: Pixel electrode

[0052] 240: Insulation layer

[0053] 240O: Open

[0054] L1: Distance

[0055] CB1, CB2, CB3: Partial

[0056] GL, GL0~GL3: scan line

[0057] BL, BL0~BL3: Bias line

[0058] RL: Low potential line

[0059] PL: Shielding potential line

[0060] DL: Data line

[0061] DC: Data drive circuit

[0062] PU: Pixel Unit

[0063] GC: Scanning Circuit

[0064] BC: Bias Circuit

[0065] RS: Low potential source

[0066] PS: Shielding potential source

[0067] D1,D2,N: Direction

[0068] C1, C2, C3: Contacts

[0069] L2, L3: Length

[0070] G1: Clearance DETAILED DESCRIPTION

[0071] The present invention will provide many different implementations or embodiments to implement the different features of the subject matter provided. Many components and configurations will be described below with specific embodiments to simplify the present invention. Of course, these embodiments are only used for illustration and are not intended to limit the present invention. For example, the statement "a first feature is formed on a second feature" includes multiple implementations, including the first feature directly contacting the second feature, and additional features formed between the first feature and the second feature so that the two are not in direct contact.

[0072] Figure 1Ais a top view schematically showing a light sensing device 100 according to some embodiments of the present invention. Figure 1B is along Figure 1A 1B-1B of FIG. 1B is a cross-sectional view of FIG. 1B-1B. The light sensing device 100 includes a substrate 110, a gate electrode 122, a shielding electrode 124, an insulating layer 130, a semiconductor layer 142, a source / drain electrode 152S, and a drain / source electrode 152D. The gate electrode 122 and the shielding electrode 124 are disposed on the substrate 110, and the two are separated. The insulating layer 130 is disposed on the gate electrode 122 and the shielding electrode 124. The semiconductor layer 142 is disposed on the insulating layer 130. The source / drain electrode 152S and the drain / source electrode 152D are respectively connected to the semiconductor layer 142.

[0073] In some embodiments, the semiconductor layer 142 has a channel region 142C between the source / drain electrodes 152S and 152D. In some embodiments, the gate electrode 122 is offset (offset for short), so that the channel region 142C is divided into a switch region 142CA and a photosensitive region 142CB, wherein the switch region 142CA overlaps with the gate electrode 122 in the direction N, and the photosensitive region 142CB does not overlap with the gate electrode 122 in the direction N. In some embodiments, the boundary between the switch region 142CA and the photosensitive region 142CB is aligned with the edge of the gate electrode 122. Thereby, the electron channel of the entire channel region 142C of the semiconductor layer 142 (i.e., the switch region 142CA and the photosensitive region 142CB) is controlled by light and can sense light, and the electron channel of the switch region 142CA of the semiconductor layer 142 can be further controlled by the gate electrode 122.

[0074] Thus, when operating the light sensing device 100, an appropriate voltage is applied to the gate electrode 122, and the light is sensed through the switch region 142CA and the photosensitive region 142CB of the semiconductor layer 142 to generate a current, and the current is detected to calculate the amount of light. In one embodiment, a positive voltage can be applied to the gate electrode 122 to turn on the switch region 142CA, and the semiconductor layer 142 senses the light to generate a current. At this time, the magnitude of the current is mainly controlled by the photosensitive region 142CB. In another embodiment, a negative voltage can be applied to the gate electrode 122 to inhibit the switch region 142CA, and the semiconductor layer 142 senses the light to generate a current. At this time, the magnitude of the current is mainly controlled by the switch region 142CA and the photosensitive region 142CB. In the embodiment where a negative voltage is applied to the gate electrode 122, the change of the current affected by the light intensity is more obvious, so that the light sensing device 100 has a higher light intensity resolution. The optical sensing device 100 of this embodiment has the advantage of high light intensity resolution and can be used for optical fingerprint recognition. Fingerprint recognition is achieved by sensing the reflected light of the fingerprint path, which can improve the accuracy of fingerprint recognition.

[0075] Here, the “inhibited” switch region 142CA refers to the resistance of the semiconductor layer 142 being increased by an external electric field (e.g., applying a voltage to the gate electrode 122). In contrast, the “on” switch region 142CA refers to the resistance of the semiconductor layer 142 being decreased by an external electric field (e.g., applying a voltage to the gate electrode 122).

[0076] In some cases, the electric field at the edge of the gate electrode 122 may affect the electron channel of the photosensitive region 142CB in the semiconductor layer 142, causing the sensed current to deviate from the expected value. For example, when a positive voltage is applied to the gate electrode 122 to turn on the switch region 142CA, the electric field at the edge of the gate electrode 122 may partially turn on the electron channel of the photosensitive region 142CB, causing the sensed current to be larger than the expected value. When a negative voltage is applied to the gate electrode 122 to inhibit the switch region 142CA, the electric field at the edge of the gate electrode 122 may partially close the electron channel of the photosensitive region 142CB, causing the sensed current to be smaller than the expected value.

[0077] In some embodiments of the present invention, from the schematic top view, the shielding electrode 124 is located on the side of the gate electrode 122 facing the photosensitive region 142CB. For example, the shielding electrode 124 partially overlaps with the photosensitive region 142CB of the semiconductor layer 142 in the direction N. In some embodiments, the shielding electrode 124 can be connected to a ground potential. In this way, the shielding electrode 124 can cause a shielding effect, thereby preventing the electric field at the edge of the gate electrode 122 from affecting the electron channel of the photosensitive region 142CB in the semiconductor layer 142. Thereby, the difference between the induced current and the expected value can be reduced.

[0078] The insulating layer 130 may include an insulating portion 132 to separate the gate electrode 122 from the shielding electrode 124. In some embodiments, the distance L1 of the gap G1 between the gate electrode 122 and the shielding electrode 124 (i.e., the length of the insulating portion 132) is as small as possible. In some embodiments, the minimum value of the distance L1 depends on the process resolution. For example, when the process adopts the process capability of a liquid crystal display, the minimum value of the distance L may be approximately 2um. Or, when the process adopts an integrated circuit process, the minimum value of the distance L1 may be approximately 3nm to approximately 28nm. In some embodiments, the insulating layer 130 may be formed of a suitable insulating material, such as silicon nitride, silicon oxide, silicon oxynitride, or a combination thereof.

[0079] In some embodiments, the substrate 110 may be a rigid substrate or a flexible substrate with appropriate hardness. The substrate 110 may be made of glass, quartz, an organic material such as a polymer material, other suitable materials, or a combination thereof.

[0080] In some embodiments, the gate electrode 122 and the shielding electrode 124 may be formed of a suitable conductive material, such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, other metals, alloys thereof, or combinations thereof. In some embodiments, the gate electrode 122 and the shielding electrode 124 are formed of the same conductive material. For example, a metal layer is deposited on the substrate 110, and the metal layer is patterned by an etching step to form the gate electrode 122 and the shielding electrode 124.

[0081] In some embodiments, the semiconductor layer 142 may be made of a semiconductor material with an appropriate bandgap, which can absorb light and change its resistance accordingly. For example, the semiconductor layer 142 may be formed of an appropriate semiconductor material, such as amorphous silicon, other appropriate materials, or a combination thereof.

[0082] In some embodiments, the source / drain electrode 152S and the drain / source electrode 152D may be formed of a suitable conductive material, such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, other metals, alloys thereof, or combinations thereof. In some embodiments, the source / drain electrode 152S and the source / drain / source electrode 152D are formed of the same conductive material. For example, a metal layer is deposited on the substrate 110, and the metal layer is patterned through an etching step to form the source / drain electrode 152S and the drain / source electrode 152D. In some embodiments, the shielding electrode 124 and the gate electrode 122 are adjacent to the source / drain electrode 152S and the drain / source electrode 152D, respectively. In this embodiment, the gate electrode 122 may extend below the drain / source electrode 152D, and the shielding electrode 124 may not extend below the source / drain electrode 152S.

[0083] In some embodiments, the photosensitive region 142CB of the semiconductor layer 142 has first to third portions CB1, CB2, and CB3, and the first portion CB1 and the third portion CB3 are respectively connected to the two ends of the second portion CB2. In this embodiment, the second portion CB2 overlaps with the shielding electrode 124 in the direction N, the first portion CB1 is located between the switch region 142CA and the second portion CB2 and does not overlap with the shielding electrode 124 in the direction N, and the third portion CB3 is located on a side of the second portion CB2 away from the first portion CB1 and does not overlap with the shielding electrode 124 in the direction N. The first portion CB1 is adjacent to the drain / source electrode 152D, and the third portion CB3 is adjacent to the source / drain electrode 152S. For the sake of convenience, the junction of the first portion CB1 and the second portion CB2 of the photosensitive region 142CB is defined as an edge of the aligned shielding electrode 124, and the junction of the second portion CB2 and the third portion CB3 of the photosensitive region 142CB is defined as another edge of the aligned shielding electrode 124.

[0084] In some embodiments, the fringe electric field of the gate electrode 122 is shielded by the shielding electrode 124, for example, the electric line EL is blocked by the shielding electrode 124 and does not affect the second portion CB2 of the photosensitive region 142CB. In some embodiments, in view of the fact that the first portion CB1 of the photosensitive region 142CB is still affected by the fringe electric field of the gate electrode 122 (for example, part of the electric line EL extends to the first portion CB1), in order to reduce the influence of the fringe electric field on the measured current, the sum of the length L2 of the second portion CB2 of the photosensitive region 142CB and the length L3 of the third portion CB3 can be designed to be much greater than the length of the first portion CB1 of the photosensitive region 142CB (i.e., the distance L1). In some embodiments, the length L2 of the second portion CB2 of the photosensitive region 142CB is greater than the length of the first portion CB1 of the photosensitive region 142CB (i.e., the distance L1). In some embodiments, the length L3 of the third portion CB3 of the photosensitive region 142CB is greater than the length of the first portion CB1 of the photosensitive region 142CB (i.e., the distance L1). In this embodiment, the length L2 of the second portion CB2 is greater than the length L3 of the third portion CB3. Alternatively, in other embodiments, the length L3 of the third portion CB3 is greater than the length L2 of the second portion CB2. In other embodiments, the size ratios of the first portion CB1, the second portion CB2 and the third portion CB3 of the photosensitive region 142CB of the semiconductor layer 142 can be adjusted arbitrarily and are not limited to the figures.

[0085] Figure 2A is a top view schematically showing a light sensing device 100 according to some embodiments of the present invention. Figure 2B is along Figure 2A The cross-sectional view of the line 2B-2B of FIG. Figure 1A and 1B The shielding electrode 124 is similar, but different in that the shielding electrode 124 extends below the source / drain electrode 152S. The shielding electrode 124 may extend beyond the side 142E of the semiconductor layer 142 , so that the photosensitive region 142CB of the semiconductor layer 142 is almost completely located on the shielding electrode 124 .

[0086] For example, here, the photosensitive region 142CB of the semiconductor layer 142 has a first portion CB1 and a second portion CB2, the second portion CB2 overlaps with the shielding electrode 124 in the direction N, and the first portion CB1 is located between the switch region 142CA and the second portion CB2 and does not overlap with the shielding electrode 124 in the direction N. In other words, in this embodiment, the semiconductor layer 142 may not have a third portion CB3 (refer to Figure 1A and 1B ). Other details of this embodiment are roughly as described above and will not be repeated here.

[0087] Figure 3AFIG. 2 is a top view schematically showing a light sensing panel 200 according to some embodiments of the present invention. Figure 3B yes Figure 3A The circuit diagram of the pixel unit PU of the light sensing panel 200 is shown in FIG. In the present embodiment, the light sensing panel 200 includes a plurality of scan lines GL (e.g., scan lines GL0-GL3), bias lines BL (e.g., bias lines BL0-BL3), a low potential line RL, a shielding potential line PL, a plurality of pixel units PU, a scan circuit GC, and a bias circuit BC.

[0088] In some embodiments of the present invention, the scan line GL, the bias line BL and the low potential line RL are not electrically connected to each other. In some embodiments, the scan line GL extends along the first direction D1, and the bias line BL extends along the second direction D2, wherein the first direction D1 and the second direction D2 are interlaced. For example, the first direction D1 and the second direction D2 are perpendicular to each other. The low potential line RL and the shielding potential line PL are appropriately distributed. In this embodiment, the low potential line RL extends along the first direction D1 and is parallel to the scan line GL, and the shielding potential line PL extends along the second direction D2 and is parallel to the bias line BL. Of course, this should not limit the scope of the present invention. In other embodiments, the low potential line RL may extend along the second direction D2 and is parallel to the bias line BL, and the shielding potential line PL may extend along the first direction D1 and is parallel to the scan line GL. In other embodiments, the low potential line RL and the shielding potential line PL may extend along the same direction, such as the first direction D1 or the second direction D2.

[0089] In the present embodiment, each pixel unit PU is connected to a scan line GL (e.g., scan lines GL0 to GL3) and a bias line BL (e.g., bias lines BL0 to BL3). The scan line GL (e.g., scan lines GL0 to GL3) can be connected to a scan circuit GC to provide signals to the pixel unit PU in a timely manner. The bias line BL (e.g., bias lines BL0 to BL3) can be connected to a bias circuit BC to provide signals to the pixel unit PU in a timely manner. The low potential line RL is connected to a low potential source RS, wherein the low potential source RS provides an appropriate stable bias potential, such as a ground potential. The shielding potential line PL is connected to a shielding potential source PS, which provides an appropriate stable bias potential, such as a ground potential.

[0090] In some embodiments, each pixel unit PU includes a light sensing device 100 and a sensing switch element 210. The light sensing device 100 includes a control terminal 100G, a first terminal 100S, a second terminal 100D, and a shielding terminal 100P, wherein the resistance between the first terminal 100S and the second terminal 100D can be controlled by light and the control terminal 100G, so that the light sensing device 100 can sense light. For example, the control terminal 100G, the first terminal 100S, the second terminal 100D, and the shielding terminal 100P of the light sensing device 100 correspond to Figures 1A to 2B The gate electrode 122 , the source / drain electrode 152S, the drain / source electrode 152D and the shielding electrode 124 are provided.

[0091] In this embodiment, the sensing switch element 210 includes a control terminal 210G, a first terminal 210S, and a second terminal 210D, wherein the control terminal 210G is used to control the conduction between the signal terminal first terminal 210S and the second terminal 210D. In this embodiment, the control terminal 210G is electrically connected to the scan line GL, the first terminal 210S is electrically connected to the control terminal 100G and the second terminal 100D of the light sensing device 100, and the second terminal 210D is electrically connected to the bias line BL. In this embodiment, the first terminal 100S can be connected to the low potential line RL.

[0092] The potential of the low potential source RS can be lower than the potential of the signal provided by the bias circuit BC in sequence, so that there is a voltage difference between the bias line BL and the low potential line RL. Thus, when the sensing switch element 210 is turned on through the scan line GL, when the light sensing device 100 senses light, the current provided by the bias line BL can flow through the second end 210D of the sensing switch element 210 to the first end 210S and the control end 100G, so that the control end 100G of the light sensing device 100 is turned on, and then flows through the second end 100D of the light sensing device 100 to the first end 100S to the low potential line RL, wherein the resistance value between the second end 100D and the first end 100S of the light sensing device 100 is affected by light. Thus, the light intensity sensed by the light sensing device 100 can be determined by monitoring this current value. For example, the current value transmitted from the bias line BL to the ground potential (e.g., the potential of the low potential source RS or a ground potential in the bias circuit BC) can be measured to determine the sensed light intensity. In some implementations, since the intensity of the sensed light is obtained via the current carried by the bias line BL, the bias line BL may also be referred to as a readoutline.

[0093] In some embodiments, the shielding end 100P of the light sensing device 100 may be electrically connected to the shielding potential line PL to create a shielding effect and improve the photosensitivity accuracy of the light sensing device 100. In some embodiments, the scan line GL, the bias line BL, and the shielding potential line PL are not electrically connected to each other. The shielding potential line PL and the low potential line RL may or may not be electrically connected.

[0094] Figure 3C yes Figure 3B A cross-sectional schematic diagram of a pixel unit PU. Figure 3D yes Figure 3C A top view of the light sensing device 100 of the pixel unit PU. The insulating layer 130 may be provided with a contact C1 to connect the gate electrode 122 and the drain / source electrode 152D of the light sensing device 100 to achieve electrical connection between the two. Figure 3B In some embodiments, a contact opening is etched in the insulating layer 130, a conductive material is filled in the contact opening, and a planarization process is performed to remove the conductive material outside the contact opening, thereby forming the contact C1. The conductive material of the contact C1 may be, for example, molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, other metals, alloys thereof, or combinations thereof.

[0095] In some embodiments, the sensing switch element 210 may include a gate electrode 126, a semiconductor layer 144, a first drain / source electrode 154S, and a second source / drain electrode 154D. The gate electrode 126, the first drain / source electrode 154S, and the second drain / source electrode 154D of the sensing switch element 210 may respectively constitute Figure 3A and 3B The control end 210G, the first end 210S, and the second end 210D of the sensing switch element 210 are shown in FIG. In the present embodiment, the gate electrode 126 is disposed on the substrate 110 and is separated from the gate electrode 122 and the shielding electrode 124. The insulating layer 130 is disposed on the gate electrode 126. The semiconductor layer 144 is disposed on the insulating layer 130. The first drain / source electrode 154S and the second drain / source electrode 154D are respectively connected to the semiconductor layer 144.

[0096] In some embodiments, the gate electrode 126 of the sensing switch element 210 and the gate electrode 122 of the light sensing device 100 are formed by patterning the same layer. In some embodiments, the semiconductor layer 144 of the sensing switch element 210 and the semiconductor layer 142 of the light sensing device 100 are formed by patterning the same semiconductor layer. In some embodiments, the source / drain electrode 154S and the second drain / source electrode 154D of the sensing switch element 210 and the source / drain electrode 152S and the drain / source electrode 152D of the light sensing device 100 are formed by patterning the same conductive layer. Accordingly, the gate electrode 126, the semiconductor layer 144, the source / drain electrode 154S, and the drain / source electrode 154D of the sensing switch element 210 respectively include the same material and have similar layer thicknesses as the gate electrode 122, the semiconductor layer 142, the source / drain electrode 152S, and the drain / source electrode 152D of the light sensing device 100. The source / drain electrode 154S may be structurally connected to the drain / source electrode 152D to Figure 3B In various embodiments of the present invention, the light sensing device 100 and the sensing switch element 210 may use an N-type channel or a P-type channel, and are not limited to those shown in the figure. In addition, in one embodiment, the semiconductor layer 142 and the semiconductor layer 144 may include amorphous silicon and n-type lightly doped (n+) amorphous silicon.

[0097] Back to Figure 3B In this embodiment, the low potential source RS and the shielding potential source PS may be at different potentials, and the low potential line RL and the shielding potential line PL may not be electrically connected. Alternatively, in other embodiments, the low potential source RS and the shielding potential source PS are at the same potential, such as a ground potential, and the low potential line RL and the shielding potential line PL may be electrically connected. In an embodiment in which the low potential line RL and the shielding potential line PL are electrically connected, the first end 100S (or the low potential line RL) of the light sensing device 100 and the shielding electrode 124 (or the shielding potential line PL) may be structurally connected, or the low potential line RL and the shielding potential line PL may be structurally connected. Please refer to the subsequent Figure 4A and Figure 4B .

[0098] Figure 4A FIG. 2 is a top view schematically showing a light sensing panel 200 according to some embodiments of the present invention. Figure 4B yes Figure 4A The circuit diagram of the pixel unit PU of the light sensing panel 200 is shown in FIG. Figure 3A and 3BThe difference is that in this embodiment, the first terminal 100S and the shielding terminal 100P of the light sensing device 100 can be connected to the same low potential source RS through the low potential line RL, wherein the low potential source RS provides an appropriate stable bias potential, such as a ground potential. In this way, the shielding potential line PL and the shielding potential source PS (see Figure 3A and 3B ) settings.

[0099] Figure 4C yes Figure 4B A cross-sectional schematic diagram of a pixel unit PU. Figure 4D yes Figure 4C A top view schematic diagram of a light sensing device of a pixel unit PU. In this embodiment, a contact C2 may be provided in the insulating layer 130 to connect the shielding electrode 124 and the source / drain electrode 152S of the light sensing device 100 to achieve electrical connection between the two. In some embodiments, contact openings are etched in the insulating layer 130 by etching, conductive material is filled in the contact openings, and a planarization process is performed to remove the conductive material outside the contact openings, thereby forming contacts C1 and C2. The conductive material of the contacts C1 and C2 may be, for example, molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, other metals, alloys thereof, or combinations thereof. Other details of this embodiment are as described above. FIG. 3A to FIG. 3D The implementation method will not be described in detail here.

[0100] Figure 5A 2 is a top view schematic diagram of a light sensing display panel 200' according to some embodiments of the present invention. Figure 3A and 3B Similar, the difference is: in this embodiment, the light sensing display panel 200' may also include data lines DL (such as data lines DL0, DL1) and a data driving circuit DC, and the pixel unit PU may further include a display switch element 220 and a pixel electrode 230, so that the light sensing display panel 200' can achieve the display effect.

[0101] In some embodiments, the data driving circuit DC is used to provide appropriate data signals to each data line DL in a timing sequence. The display switch element 220 may include a control terminal 220G, a first terminal 220S and a second terminal 220D, wherein the control terminal 220G is used to control whether the first terminal 220S and the second terminal 220D are turned on or off. The control terminal 220G may be connected to the scan line GL. The first terminal 220S and the second terminal 220D of the display switch element 220 are respectively connected to the data line DL and the pixel electrode 230. Thus, through the control of the scan circuit GC and the scan line GL, the data signal provided by the data driving circuit DC can be transmitted to each pixel electrode 230 through the data line DL in a timing sequence, thereby controlling the light intensity of each pixel to achieve the purpose of display. In one embodiment, the light sensing display panel 200' may be a liquid crystal display panel (LCD) or an organic light emitting diode panel (Active-matrixorganic light-emitting diode; AMOLED), but is not limited thereto.

[0102] In this embodiment, since the display switch element 220 and the sensing switch element 210 of the same pixel unit PU are controlled by the same scan line GL (e.g., scan lines GL0 and GL1), the display switch element 220 and the sensing switch element 210 in the same pixel unit PU can be turned on at the same time. In this way, the pixel unit PU can achieve the display effect by turning on the data line DL and the pixel electrode 230 through the display switch element 220 at the same time, and can achieve the purpose of sensing light by turning on the light sensing device 100 and the bias line BL through the sensing switch element 210. By setting the light sensing device 100 and the pixel electrode 230 in the same pixel unit PU, the resolution of the light sensing device 100 is equivalent to the resolution of the pixel electrode 230 used for display, thereby improving the sensing resolution and achieving applications such as fingerprint recognition.

[0103] Figure 5B yes Figure 5A In some embodiments, the display switch element 220 may include a gate electrode 128, a semiconductor layer 146, a source / drain electrode 156S, and a drain / source electrode 156D. The gate electrode 128, the source / drain electrode 156S, and the drain / source electrode 156D of the display switch element 220 may respectively constitute Figure 5A2 shows the control end 220G, the first end 220S, and the second end 220D of the switch element 220. In this embodiment, the gate electrode 128 is disposed on the substrate 110 and is separated from the gate electrodes 122, 124 and the shielding electrode 124. The insulating layer 130 is disposed on the gate electrode 128. The semiconductor layer 146 is disposed on the insulating layer 130. The source / drain electrode 156S and the drain / source electrode 156D are respectively connected to the semiconductor layer 146.

[0104] In some embodiments, the gate electrodes 128, 122, 126 and the shielding electrode 124 are formed by patterning the same layer and have the same material and similar thickness. In some embodiments, the semiconductor layers 146, 142, 144 are formed by patterning the same layer and have the same material and similar thickness. In some embodiments, the drain / source electrodes 156D, 152D, 154D and the source / drain electrodes 152S, 154S, 156S are formed by patterning the same layer and have the same material and similar thickness.

[0105] In some embodiments, an insulating layer 240 may be deposited on the device. The insulating layer 240 may be formed of a suitable insulating material, such as silicon nitride, silicon oxide, silicon oxynitride, or a combination thereof. The pixel electrode 230 may be disposed on the insulating layer 240 and may be formed of a suitable transparent or opaque conductive material. The opaque conductive material may be a metal, such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, other metals, alloys thereof, or a combination thereof. The transparent conductive material may be, for example, indium tin oxide, nanometal wires (such as nanosilver wires), or a combination thereof, and its light transmittance may be greater than 60% or greater than 80%. An opening 240O may be opened in the insulating layer 240 and filled with a suitable conductive material to form a contact C3, thereby electrically connecting the pixel electrode 230 to the drain / source electrode 156D through the contact C3. In some embodiments, a suitable transparent or opaque conductive material may be deposited on the insulating layer 240 and in the opening 240O, and then the transparent conductive material may be patterned through processes such as photolithography and etching to form the pixel electrode 230 and the contact C3. Other details are similar to those described above. Figure 3A and 3B The related implementation methods have been described and will not be elaborated here.

[0106] Figure 6 FIG. 2 is a top view schematically showing a light sensing panel 200 according to some embodiments of the present invention. Figures 3A to 3D as well as Figures 4A to 4D The difference is that the pixel unit PU of the light sensing panel 200 does not include the sensing switch element 210. In this embodiment, by adjusting the configuration of the gate electrode 122 and the semiconductor layer 142 (refer to Figure 1A ,1B For example, by adjusting the length of the switch area 142CA or shielding the switch area 142CB), the light sensing device 100 may be sufficient to inhibit the pixel unit PU from turning on when exposed to light through its own control terminal 100G, without the need for a sensing switch element 210 (see FIG. 5 ).

[0107] In this embodiment, the second end 100D and the control end 100G of the light sensing device 100 are connected to the scan line GL, and the first end 100S of the light sensing device 100 is connected to the low potential line RL. Thus, when the light sensing device 100 senses light and changes (e.g., reduces) the resistance value of the semiconductor layer, the signal of the scan line GL is transmitted from the second end 100D to the first end 100S, and then to the low potential line RL. In this embodiment, the shielding end 100P of the light sensing device 100 is connected to the shielding potential source PS via the shielding potential line PL. Other details of this embodiment are roughly as described above and will not be repeated here.

[0108] Figure 7 FIG. 2 is a top view schematically showing a light sensing panel 200 according to some embodiments of the present invention. Figure 6 The difference is that the shielding end 100P of the optical sensing device 100 can be directly connected to the first end 100S of the optical sensing device 100, and then connected to the low potential source RS via the low potential line RL, and the shielding potential line PL and the shielding potential source PS can be omitted (refer to Figure 6 The specific structure of the optical sensing device 100 of this embodiment can be referred to Figure 4C , 4D The light sensing device 100 is shown in FIG. 1 , and other details are not described in detail.

[0109] Figure 8 2 is a top view schematic diagram of a light sensing display panel 200' according to some embodiments of the present invention. Figure 6 Similar, the difference is: in this embodiment, the pixel unit PU may further include a display switch element 220 and a pixel electrode 230, so that the light sensing panel 200 can achieve the display effect. The specific structure of the display switch element 220 and the pixel electrode 230 of this embodiment can be referred to Figure 5B The specific structure of the optical sensing device 100 can be referred to Figure 4C and Figure 4D The other details of the optical sensing device 100 are substantially the same as before. Figure 6 The related implementation methods have been described and will not be repeated here.

[0110] In some embodiments of the present invention, electrodes 152D, 154D, and 156D may be referred to as first drain / source electrodes, and electrodes 152S, 154S, and 156S may be referred to as second source / drain electrodes. Alternatively, in some embodiments of the present invention, electrodes 152S, 154S, and 156S may be referred to as first source / drain electrodes, and electrodes 152D, 154D, and 156D may be referred to as second drain / source electrodes.

[0111] In multiple embodiments of the present invention, by designing a shielding electrode in the light sensing device, a shielding effect can be created, thereby preventing the electric field at the edge of the gate electrode from affecting the electronic channel of the photosensitive area in the semiconductor layer. This light sensing device has the advantage of high light intensity resolution and can be used for optical fingerprint recognition. Fingerprint recognition is achieved by sensing the reflected light of the fingerprint path, which can improve the accuracy of fingerprint recognition. In some embodiments, by designing the light sensing device to have a gate to control some channels, the light sensing device can achieve the effects of light sensing and switching at the same time. In some embodiments, this light sensing device can be applied to a display panel, and the light sensing device and the device and pixel electrode in the display panel can be manufactured together through an appropriate integration process, thereby saving a mask.

[0112] The above summarizes the features of multiple embodiments. Those skilled in the art should understand that the present invention can be used as a basis for designing or modifying other processes or structures, and various changes, substitutions, and transformations can be made. The spirit and scope of the present invention cover these changes, substitutions, and transformations.

Claims

1. A light sensing device, characterized in that: Include: a substrate; a gate electrode disposed on the substrate; a shielding electrode disposed on the substrate and separated from the gate electrode, wherein the shielding electrode is electrically connected to a low potential line; an insulating layer, disposed on the gate electrode and the shielding electrode, wherein there is a gap between the gate electrode and the shielding electrode; a semiconductor layer disposed on the insulating layer; as well as A first drain / source electrode and a second source / drain electrode are respectively connected to the semiconductor layer, wherein the semiconductor layer has a channel region between the first drain / source electrode and the second source / drain electrode, and the channel region is divided into a first region and a second region, wherein the first region is adjacent to the first drain / source electrode and overlaps with the gate electrode, the second region is adjacent to the second source / drain electrode and does not overlap with the gate electrode, and the second region partially overlaps with the shielding electrode, wherein the second source / drain electrode is electrically connected to the low potential line.

2. The optical sensing device according to claim 1, wherein: The shielding electrode extends below the second source / drain electrode.

3. The optical sensing device according to claim 1, wherein: The shielding electrode does not extend below the second source / drain electrode.

4. The optical sensing device according to claim 1, wherein: The gate electrode and the shielding electrode are formed of the same conductive material.

5. The optical sensing device according to claim 1, wherein: The shielding electrode is electrically connected to the second source / drain electrode.

6. The optical sensing device according to claim 1, wherein: The gate electrode is electrically connected to the first drain / source electrode.

7. A light sensing panel, characterized in that: Include: The light sensing device as claimed in claim 1; A scanning line is disposed on the substrate; a bias line disposed on the substrate; A sensing switch element is disposed on the substrate, wherein a control end of the sensing switch element is electrically connected to the scan line, and two ends of the sensing switch element are electrically connected to the bias line and the first drain / source electrode of the light sensing device respectively; as well as A low potential line is disposed on the substrate and electrically connected to the second source / drain electrode of the light sensing device.

8. The light sensing panel according to claim 7, wherein: The shielding electrode is electrically connected to the low potential line or a shielding potential line disposed on the substrate.

9. The light sensing panel according to claim 7, wherein: Also includes: At least one data line is disposed on the substrate; a display switch element, wherein a control terminal of the display switch element is connected to the scan line; and A pixel electrode, wherein two ends of the display switch element are electrically connected to the data line and the pixel electrode respectively.

10. A light sensing panel, characterized in that: Include: The light sensing device as claimed in claim 1; a scan line disposed on the substrate, wherein the gate electrode of the light sensing device is electrically connected to the scan line, and the first drain / source electrode of the light sensing device is electrically connected to the scan line; and The low potential line is disposed on the substrate, wherein the second source / drain electrode of the light sensing device is electrically connected to the low potential line.

11. The light sensing panel according to claim 10, wherein: Also includes: At least one data line is disposed on the substrate; a display switch element, wherein a control terminal of the display switch element is connected to the scan line; and A pixel electrode, wherein two ends of the display switch element are electrically connected to the data line and the pixel electrode respectively.

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