Infrared imager

Abstract

The invention relates to an infrared imager, and relates to the technical field of infrared detection, and the infrared imager is provided with an isolation resistor to reduce the influence of crosstalk. The infrared imager comprises a substrate and a plurality of detection units, wherein the plurality of detection units are arranged on one side of the substrate in an array; each detection unit comprises a thin film transistor, a diode detector and an isolation resistor; the thin film transistor at least comprises a control end and a first end, the diode detector is connected between the control end and the first end of the thin film transistor, and the isolation resistor is connected in parallel with the diode detector; the thin film transistor and the diode detector are switched on when receiving the first bias voltage and switched off when receiving the second bias voltage; the isolation resistor is used for eliminating leakage current among the plurality of diode detectors.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of infrared detection, and particularly relates to an infrared imager. BACKGROUND

[0002] At present, most of the focal plane devices applied by colloidal quantum dots are based on CMOS (complementary metal-oxide-semiconductor) image sensors. CMOS is integrated on a semiconductor material called metal oxide. The process is the same as the process of producing semiconductor integrated circuits such as computer chips and storage devices.

[0003] However, in the high-end field with high requirements for the performance of the detector, the CMOS sensor has the disadvantages of insufficient sensitivity and resolution. In the field of large array sensors, the size of the large array CMOS image sensor is limited, the spatial resolution is low, and the crosstalk is large. Moreover, the allowable working voltage of the CMOS device is low, which cannot meet the needs of the high-end market such as military detection, aerospace, and auxiliary driving, thereby limiting the further promotion and application of the colloidal quantum dot detector.

[0004] The prior art further improves the process by replacing the CMOS tube with a thin film transistor. However, the large array thin film transistor image sensor has large crosstalk and large device noise in the working process, which affects the signal-to-noise ratio of the device and the imaging quality, and is not conducive to further promotion and application. SUMMARY

[0005] In order to solve the above technical problems, the present disclosure provides an infrared imager. The infrared imager reduces the influence of crosstalk by setting an isolation resistor.

[0006] The present disclosure provides an infrared imager, which comprises a substrate and a plurality of detection units, the plurality of detection units are arranged in an array on one side of the substrate; a single detection unit comprises a thin film transistor, a diode detector and an isolation resistor; the thin film transistor comprises at least a control end and a first end, the diode detector is connected between the control end and the first end of the thin film transistor, and the isolation resistor is connected in parallel with the diode detector; the thin film transistor and the diode detector are used to turn on when receiving a first bias voltage and turn off when receiving a second bias voltage; and the isolation resistor is used to eliminate the leakage current between the plurality of diode detectors.

[0007] Optionally, the isolation resistor comprises a first bottom electrode, a first carrier transport layer, a first quantum dot layer, a second quantum dot layer, a third quantum dot layer, a second carrier transport layer and a first top electrode which are arranged in a stack on one side of the substrate and away from the substrate; wherein the first carrier transport layer and the second carrier transport layer are respectively used to transport one of an electron and a hole; a plurality of the first bottom electrodes are arranged in a grid and connected with a ground electrode, and the leakage current flows into the ground electrode through the first bottom electrode.

[0008] Optionally, the thin film transistor also includes: a second end; a gate signal line, a bias signal line and a signal readout line are also provided on the substrate; the control end of the thin film transistor is electrically connected to the gate signal line, the diode detector is connected between the bias signal line and the first end of the thin film transistor, and the second end of the thin film transistor is electrically connected to the signal readout line; wherein the gate signal line crosses the bias signal line to separate the multiple detection units; the signal readout line is parallel to the bias signal line.

[0009] Optionally, the diode detector includes: a second bottom electrode, a third carrier transport layer, a fourth quantum dot layer, a fifth quantum dot layer, a sixth quantum dot layer, a fourth carrier transport layer and a second top electrode stacked on one side of the substrate and in a direction away from the substrate; wherein the second bottom electrode is electrically connected to the control end of the thin film transistor; the conductivity of the first bottom electrode is greater than the conductivity of the second bottom electrode; the third carrier transport layer is arranged in the same layer as the first carrier transport layer, and the fourth carrier transport layer is arranged in the same layer as the second carrier transport layer; the fourth quantum dot layer is arranged in the same layer as the first quantum dot layer, the fifth quantum dot layer is arranged in the same layer as the second quantum dot layer, and the sixth quantum dot layer is arranged in the same layer as the third quantum dot layer.

[0010] Optionally, the detection unit includes a fifth carrier transport layer, a seventh quantum dot layer, an eighth quantum dot layer, a ninth quantum dot layer, a sixth carrier transport layer and a third top electrode shared by the diode detector and the isolation resistor; the diode detector also includes: a third bottom electrode; the isolation resistor also includes: a fourth bottom electrode; wherein the fifth carrier transport layer and the sixth carrier transport layer are respectively used to transport one of electrons and holes; a plurality of the fourth bottom electrodes are arranged in a grid and connected to the ground electrode, and the leakage current flows into the ground electrode through the fourth bottom electrode.

[0011] Optionally, the first top electrode and the second top electrode are a whole; or the first top electrode and the second top electrode are electrically connected.

[0012] Optionally, one of the first quantum dot layer and the third quantum dot layer is an N-type quantum dot layer, and the other is a P-type quantum dot layer; one of the fourth quantum dot layer and the sixth quantum dot layer is an N-type quantum dot layer, and the other is a P-type quantum dot layer; the second quantum dot layer includes: a first intrinsic quantum dot layer; the fifth quantum dot layer includes: a second intrinsic quantum dot layer; wherein, the first intrinsic quantum dot layer and the second intrinsic quantum dot layer generate photoelectric signals in response to different bands.

[0013] Optionally, one of the seventh quantum dot layer and the ninth quantum dot layer is an N-type quantum dot layer, and the other is a P-type quantum dot layer; the eighth quantum dot layer comprises: a third intrinsic quantum dot layer; wherein the third intrinsic quantum dot layer generates a photoelectric signal in response to different wave bands.

[0014] Optionally, the thickness of the first top electrode is 20-40 nanometers; the thickness of the second top electrode is 20-40 nanometers; the thickness of the third top electrode is 20-40 nanometers; the thickness of the N-type quantum dot layer is 50-200 nanometers; the thickness of the P-type quantum dot layer is 50-200 nanometers; the thickness of the first intrinsic quantum dot layer is 300-400 nanometers; the thickness of the second intrinsic quantum dot layer is 300-400 nanometers; and the thickness of the third intrinsic quantum dot layer is 300-400 nanometers.

[0015] Optionally, the infrared imager further comprises: a converging lens and a data acquisition module, the converging lens is arranged between the imaging object and the detection unit; the converging lens is used for converging light of the imaging object onto the detection unit; the data acquisition module is electrically connected with the signal readout line; and the data acquisition module is used for processing a photoelectric signal generated by the detection unit in response to the light of the imaging object.

[0016] The technical scheme provided by the embodiments of the present disclosure has the following advantages compared with the prior art: The infrared imager provided by the embodiments of the present disclosure realizes the effect of eliminating the leakage current by adding an isolation resistor in the detection unit, so that the leakage current generated by the diode detector is guided to the ground through the isolation resistor, thereby avoiding the crosstalk caused by the current flowing in the detection unit. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure.

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the present disclosure or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, and obviously, other accompanying drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 A structural schematic diagram of an infrared imager provided by the embodiments of the present disclosure is shown in the figure; Figure 2 A structural schematic diagram of an isolation resistor provided by the embodiments of the present disclosure is shown in the figure; Figure 3An equivalent circuit diagram of an infrared imager provided by an embodiment of the present disclosure is provided. Figure 4 A structural schematic diagram of a diode detector provided by an embodiment of the present disclosure is provided. Figure 5 Another structural schematic diagram of an infrared imager provided by an embodiment of the present disclosure is provided. Figure 6 Still another structural schematic diagram of an infrared imager provided by an embodiment of the present disclosure is provided. Figure 7 Still another structural schematic diagram of an infrared imager provided by an embodiment of the present disclosure is provided. Figure 8 A backboard structural schematic diagram of an infrared imager provided by an embodiment of the present disclosure is provided. Figure 9 A working principle schematic diagram of an infrared imager provided by an embodiment of the present disclosure is provided.

[0020] In the figure, 1, substrate; 11, gate signal line; 12, bias signal line; 13, signal readout line; 2, detection unit; 21, thin film transistor; 210, control end; 211, first end; 212, second end; 22, diode detector; 23, isolation resistor; 231, first bottom electrode; 232, first carrier transport layer; 233, first quantum dot layer; 234, second quantum dot layer; 2341, first intrinsic quantum dot layer; 235, third quantum dot layer; 236, second carrier transport layer; 237, first top electrode; 221, second bottom electrode; 222, third carrier transport layer; 223, fourth quantum dot layer; 224, fifth quantum dot layer; 2241, second intrinsic quantum dot layer; 225, sixth quantum dot layer; 226, fourth carrier transport layer; 227, second top electrode; 242, fifth carrier transport layer; 243, seventh quantum dot layer; 244, eighth quantum dot layer; 2441, third intrinsic quantum dot layer; 245, ninth quantum dot layer; 246, sixth carrier transport layer; 247, third top electrode; 3, converging lens; 4, data acquisition module; 100, infrared imager. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned purposes, features and advantages of the present disclosure, the schemes of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0022] In the following description, many specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure can also be implemented in other ways different from those described herein; obviously, the embodiments in the description are only some of the embodiments of the present disclosure, not all the embodiments.

[0023] Based on this, as Figure 1 shown, Figure 1 A structural schematic diagram of an infrared imager is provided for the embodiments of the present disclosure. The infrared imager 100 comprises a substrate 1 and a plurality of detection units 2.

[0024] The plurality of detection units 2 are arranged in an array on one side of the substrate 1; a single detection unit 2 comprises a thin-film transistor 21, a diode detector 22 and an isolation resistor 23.

[0025] The thin-film transistor 21 comprises at least a control end 210 and a first end 211; the diode detector 22 is connected between the control end 210 and the first end 211 of the thin-film transistor 21, and the isolation resistor 23 is connected in parallel with the diode detector 22.

[0026] The thin-film transistor 21 and the diode detector 22 are used to turn on when receiving a first bias and turn off when receiving a second bias; the isolation resistor 23 is used to eliminate the leakage current between the plurality of diode detectors 22.

[0027] In some embodiments, the above-mentioned substrate 1 is a glass substrate. The above-mentioned diode detector 22 is a photodiode, and the number of photodiodes can be one or more.

[0028] Thin-film transistor (TFT) is a special field effect transistor; its core feature is that the current flowing through the semiconductor channel is a very thin layer of semiconductor material deposited on a non-single crystal silicon substrate (such as glass or plastic).

[0029] Since the entire manufacturing process of the thin-film transistor is based on a "planarization" and "low temperature" process, it is realized by depositing and patterning thin film materials layer by layer on a cheap, non-single crystal, large-area substrate (such as glass or plastic), so it can be prepared in large area, and compared with CMOS tube, the thin-film transistor only has one (or a few) output node for unified reading, and the consistency of its signal output is very good.

[0030] Since the plurality of detection units 2 are arranged in an array, correspondingly, the plurality of diode detectors 22 are also arranged in an array, and the diode detectors 22 of adjacent pixels will have a parasitic resistance through the substrate 1, thereby forming an undesired lateral conduction channel, thereby generating a lateral leakage current. By adding the isolation resistor 23 connected in parallel with the diode detector 22, the generated lateral leakage current can be eliminated to the isolation resistor 23, and then discharged through the isolation resistor 23, and finally flows to the ground, thereby achieving the effect of eliminating the lateral leakage current, thereby protecting the detection unit 2.

[0031] For example, the diode detector 22 includes a first diode detector 22 , a second diode detector 22 and a third diode detector 22 , and the first diode detector 22 and the third diode detector 22 are disposed adjacent to the second diode detector 22 .

[0032] When the second diode detector 22 is irradiated by infrared light, it generates a large photocurrent, causing the node voltage to increase. The increased node voltage will pass through the parasitic resistance, generating a lateral leakage current, which will flow to the first diode detector 22 and the third diode detector 22 adjacent to the second diode detector 22. This lateral leakage current will change the voltage of the nodes of the first diode detector 22 and the third diode detector 22, causing the read signal to be distorted. Although the first diode detector 22 and the third diode detector 22 did not receive any light signal, they measured voltage, which is the result of crosstalk. By connecting an isolation resistor 23 in parallel at both ends of each diode detector 22, and the resistance of the isolation resistor 23 is much smaller than the parasitic resistance, and according to the characteristic that current always prefers to flow along the path with the least resistance, the lateral leakage current that was originally intended to flow from the second diode detector 22 to the first diode detector 22 or the third diode detector 22 now finds a path with much less resistance, and ultimately flows through the isolation resistor 23 of the second diode detector 22 itself to ground, thereby eliminating the impact of crosstalk.

[0033] like Figure 2 As shown, Figure 2 Figure 2 is a schematic diagram of the isolation resistor structure. The isolation resistor 23 includes a first bottom electrode 231, a first carrier transport layer 232, a first quantum dot layer 233, a second quantum dot layer 234, a third quantum dot layer 235, a second carrier transport layer 236, and a first top electrode 237, stacked on one side of the base substrate 1 and away from the base substrate 1.

[0034] Among them, the first carrier transport layer 232 and the second carrier transport layer 236 are used to transport one of electrons and holes respectively; multiple first bottom electrodes 231 are arranged in a grid and connected to the ground electrode, and the leakage current flows into the ground electrode through the first bottom electrode 231.

[0035] The isolation resistor 23 builds a high-conducting electric path through the synergistic effect of the stacked quantum dot layers and the two carrier transport layers. When connected in parallel with the diode detector 22, the isolation resistor 23 can provide a preferential conduction path for the lateral leakage current generated between pixels, which is much lower than the parasitic resistance of the substrate. At the same time, the first bottom electrode 231, which is arranged in a grid pattern and directly grounded, can efficiently conduct all the leakage current collected through the path to the ground electrode, thereby completely avoiding the diffusion of the leakage current between adjacent detection units 2, eliminating crosstalk from a physical mechanism, and significantly improving the accuracy and spatial resolution of the infrared imager 100.

[0036] In some embodiments, one of the first quantum dot layer 233 and the third quantum dot layer 235 is an N-type quantum dot layer, and the other is a P-type quantum dot layer.

[0037] For example, the first quantum dot layer 233 is an N-type quantum dot layer, and the third quantum dot layer 235 is a P-type quantum dot layer, and the corresponding thin film transistor 21 is an NMOS type transistor.

[0038] For an NMOS type transistor, when the first bias is greater than the second bias, the control end 210 of the thin film transistor 21 is turned on when receiving the first bias and turned off when receiving the second bias.

[0039] Similarly, if the first quantum dot layer 233 is a P-type quantum dot layer and the third quantum dot layer 235 is an N-type quantum dot layer, the corresponding thin film transistor 21 is a PMOS type transistor.

[0040] For a PMOS type transistor, when the first bias is less than the second bias, the control end 210 of the thin film transistor 21 is turned on when receiving the first bias and turned off when receiving the second bias.

[0041] In some embodiments, the second quantum dot layer 234 includes: a first intrinsic type quantum dot layer 2341; wherein the first intrinsic type quantum dot layer 2341 and the second intrinsic type quantum dot layer 2241 generate photoelectric signals in response to different wave bands.

[0042] As shown in FIG. 1, Figure 3 As shown in FIG. 1, Figure 3 An equivalent circuit diagram of an infrared imager provided by the embodiments of the present disclosure. The thin film transistor 21 further includes: a second end 212; and a gate signal line 11, a bias signal line 12, and a signal readout line 13 are further arranged on the substrate 1.

[0043] The control end 210 of the thin film transistor 21 is electrically connected with the gate signal line 11, the diode detector 22 is connected between the bias signal line 12 and the first end 211 of the thin film transistor 21, and the second end 212 of the thin film transistor 21 is electrically connected with the signal readout line 13.

[0044] The gate signal line 11 intersects the bias signal line 12 to separate the plurality of detection units 2 ; the signal readout line 13 is parallel to the bias signal line 12 .

[0045] In some implementations, the control terminal 210 of the thin film transistor 21 is a gate, the first terminal 211 is a source, and the second terminal 212 is a drain.

[0046] The specific process of image reading is as follows: a reverse bias is applied to the bias signal line 12, which causes the diode detector 22 to enter the detection state. At the same time, a low level is applied to the gate signal line 11 to ensure that the thin film transistor 21 is in the off state.

[0047] When infrared light strikes the diode detector 22, it generates photogenerated carriers (electron-hole pairs). These photogenerated carriers are separated by a reverse bias and accumulated at both ends of the diode detector 22 (e.g., the first carrier transport layer 232 and the second carrier transport layer 236). This results in a charge proportional to the light intensity being stored between the diode detector 22 and the first terminal 211 of the thin-film transistor 21 in each pixel, acting as a parasitic capacitor. The stronger the light, the greater the accumulated charge.

[0048] When the signal of a certain row needs to be read, a high level is applied to the gate signal line 11 corresponding to the row, and all the thin film transistors 21 switches in this row are turned on at the same time, that is, the source and drain of the thin film transistor 21 are connected; at this time, the accumulated charge is transmitted to the signal readout line 13 through the source and drain of the thin film transistor 21, and the signal readout line 13 then transmits the charge to the subsequent circuit, and the intensity of the infrared light received by the corresponding pixel is reflected according to the size of the charge.

[0049] After completing the readout of the current row, the voltage of the gate signal line 11 of this row is set low, turning off the thin film transistor 21, and the gate signal line 11 of the next row is activated to a high level. The above readout process is repeated until the signals of all rows are read in sequence, thereby completing the signal acquisition of an entire frame of image.

[0050] like Figure 4 As shown, Figure 4 A schematic structural diagram of a diode detector provided in an embodiment of the present disclosure.

[0051] In some embodiments, the diode detector 22 includes: a second bottom electrode 221, a third carrier transport layer 222, a fourth quantum dot layer 223, a fifth quantum dot layer 224, a sixth quantum dot layer 225, a fourth carrier transport layer 226 and a second top electrode 227 stacked on one side of the substrate 1 and in a direction away from the substrate 1.

[0052] The second bottom electrode 221 is electrically connected with the control terminal 210 of the thin film transistor 21; and the first bottom electrode 231 has a higher conductivity than the second bottom electrode 221.

[0053] The third carrier transport layer 222 is arranged in the same layer as the first carrier transport layer 232, and the fourth carrier transport layer 226 is arranged in the same layer as the second carrier transport layer 236; the fourth quantum dot layer 223 is arranged in the same layer as the first quantum dot layer 233, the fifth quantum dot layer 224 is arranged in the same layer as the second quantum dot layer 234, and the sixth quantum dot layer 225 is arranged in the same layer as the third quantum dot layer 235.

[0054] That is, the diode detector 22 and the isolation resistor 23 are arranged in the same layer and separated from each other, and do not affect each other. The first bottom electrode 231 with high conductivity is used as a low-resistance current drainage channel for the leakage current, and is connected with the ground electrode, so that the horizontal leakage current can be effectively drained, and the cross-talk between pixels is completely eliminated; and the second bottom electrode 221 with relatively low conductivity is more focused on ensuring the photoelectric conversion efficiency of the diode detector 22 itself. The differential electrode design ensures high-performance photoelectric detection and achieves excellent anti-crosstalk capability, and significantly improves the overall uniformity and signal-to-noise ratio of infrared imaging.

[0055] In some embodiments, one of the fourth quantum dot layer 223 and the sixth quantum dot layer 225 is an N-type quantum dot layer, and the other is a P-type quantum dot layer.

[0056] For example, the fourth quantum dot layer 223 is an N-type quantum dot layer, and the sixth quantum dot layer 225 is a P-type quantum dot layer, and the corresponding thin film transistor 21 is an NMOS type transistor.

[0057] For the NMOS type transistor, when the first bias is greater than the second bias, the control terminal 210 of the thin film transistor 21 is turned on when receiving the first bias, and is turned off when receiving the second bias.

[0058] Similarly, if the fourth quantum dot layer 223 is a P-type quantum dot layer, and the sixth quantum dot layer 225 is an N-type quantum dot layer, the corresponding thin film transistor 21 is a PMOS type transistor.

[0059] For the PMOS type transistor, when the first bias is less than the second bias, the control terminal 210 of the thin film transistor 21 is turned on when receiving the first bias, and is turned off when receiving the second bias.

[0060] In some embodiments, the fifth quantum dot layer 224 includes: a second intrinsic quantum dot layer 2241; wherein the second intrinsic quantum dot layer 2241 generates a photoelectric signal in response to different wave bands.

[0061] It should be noted that the diode detector 22 forms a photovoltaic type detector, the polarity of the quantum dot layer is controlled by different doping of the quantum dots, the N-type quantum dot layer, the intrinsic type quantum dot layer and the P-type quantum dot layer are in contact to form a PIN junction, the diffusion movement of electrons and holes is generated due to the concentration gradient of the carriers, the space charge region is generated to produce the built-in electric field. Light generates photo-generated carriers, and the electron and hole pairs are separated under the action of the built-in electric field, in which the holes diffuse to the top electrode, and the electrons diffuse to the bottom electrode to generate a photocurrent.

[0062] By changing the reaction temperature, reaction time, reactant ratio and other parameters in the quantum dot synthesis process, the waveband range of the quantum dot response is adjusted. The near-infrared, short-wave, medium-wave and long-wave infrared wavebands include the following: lead sulfide (PbS), lead selenide (PbSe), mercury telluride (HgTe) quantum dots, mercury cadmium telluride quantum dots (HgCdTe); the visible light waveband uses perovskite, cadmium telluride (CdTe) quantum dots, and the ultraviolet waveband uses perovskite quantum dots.

[0063] The colloidal quantum dots of the N-type quantum dot layer, the intrinsic type quantum dot layer and the P-type quantum dot layer are one of lead sulfide (PbS), lead selenide (PbSe), mercury telluride (HgTe), mercury selenide (HgSe), perovskite, cadmium telluride (CdTe) and mercury cadmium telluride (HgCdTe). The preparation and processing methods are spin coating, spraying, blade coating, etc.

[0064] The top electrode is one or more of nickel, chromium, titanium, gold, platinum, silver, aluminum and zinc.

[0065] Optionally, the first top electrode 237 and the second top electrode 227 are an integral whole (see Figure 5 ); or; the first top electrode 237 and the second top electrode 227 are electrically connected (see Figure 6 ).

[0066] As shown in Figure 5 , if the first top electrode 237 and the second top electrode 227 are an integral whole, the leakage current generated in the diode detector 22 can be transmitted to the isolation resistor 23 through the first top electrode 237, and then the leakage current is eliminated through the isolation resistor 23.

[0067] As shown in Figure 6 , if the first top electrode 237 and the second top electrode 227 are electrically connected, the leakage current generated in the diode detector 22 can be transmitted to the second top electrode 227 through the first top electrode 237, and then transmitted to other components of the isolation resistor 23, and finally the leakage current is eliminated through the isolation resistor 23.

[0068] It should be noted that Figure 5 and Figure 6The dotted line between the diode detector and the isolation resistor refers to the corresponding same-layer setting of the transmission layer or quantum dot layer.

[0069] like Figure 7 As shown, in some embodiments, the detection unit 2 includes a fifth carrier transport layer 242 , a seventh quantum dot layer 243 , an eighth quantum dot layer 244 , a ninth quantum dot layer 245 , a sixth carrier transport layer 246 and a third top electrode 247 shared by the diode detector 22 and the isolation resistor 23 .

[0070] The diode detector 22 further includes a third bottom electrode; the isolation resistor 23 further includes a fourth bottom electrode.

[0071] Among them, the fifth carrier transport layer 242 and the sixth carrier transport layer 246 are used to transport one of electrons and holes respectively; multiple fourth bottom electrodes are arranged in a grid and connected to the ground electrode, and the leakage current flows into the ground electrode through the fourth bottom electrodes.

[0072] This structure significantly simplifies process complexity and ensures consistent material performance by integrating the diode detector 22 with partial layers of the isolation resistor 23. Furthermore, the highly conductive first bottom electrode 231 grid serves as a low-resistance drainage channel for leakage current, connecting it to the ground electrode to efficiently channel lateral leakage current and completely eliminate crosstalk between pixels. The relatively low-conductivity second bottom electrode 221, on the other hand, focuses on ensuring the photoelectric conversion efficiency of the diode detector 22 itself. This differentiated electrode design ensures high-performance photoelectric detection while achieving excellent crosstalk resistance, significantly improving the overall uniformity and signal-to-noise ratio of infrared imaging.

[0073] In some implementations, one of the seventh quantum dot layer 243 and the ninth quantum dot layer 245 is an N-type quantum dot layer, and the other is a P-type quantum dot layer.

[0074] For example, the seventh quantum dot layer 243 is an N-type quantum dot layer, the ninth quantum dot layer 245 is a P-type quantum dot layer, and the corresponding thin film transistor 21 is an NMOS type transistor.

[0075] For an NMOS type transistor, when the first bias voltage is greater than the second bias voltage, the control terminal 210 of the thin film transistor 21 is turned on when receiving the first bias voltage, and is turned off when receiving the second bias voltage.

[0076] Similarly, if the seventh quantum dot layer 243 is a P-type quantum dot layer and the ninth quantum dot layer 245 is an N-type quantum dot layer, the corresponding thin film transistor 21 is a PMOS type transistor.

[0077] For the PMOS type transistor, the control terminal 210 of the thin film transistor 21 is turned on when receiving the first bias voltage and turned off when receiving the second bias voltage, in the case that the first bias voltage is less than the second bias voltage.

[0078] The eighth quantum dot layer 244 comprises a third intrinsic quantum dot layer 2441; the third intrinsic quantum dot layer 2441 generates a photoelectric signal in response to different wave bands.

[0079] The design realizes single-chip and pixel-level multispectral infrared imaging capability by integrating multiple layers of intrinsic quantum dots responding to different infrared wave bands in the same pixel structure, without the need for complex light splitting paths or multiple detector chips; finally, the infrared imager 100 can simultaneously acquire multiple wave band infrared information of the same target, and through fusion analysis, the accuracy and reliability of material identification, camouflage discrimination, environment monitoring and target tracking can be significantly enhanced.

[0080] Optionally, the thickness of the first top electrode 237 is 20-40 nm; the thickness of the second top electrode 227 is 20-40 nm; the thickness of the third top electrode 247 is 20-40 nm; the thickness of the N-type quantum dot layer is 50-200 nm; the thickness of the P-type quantum dot layer is 50-200 nm; the thickness of the first intrinsic quantum dot layer 2341 is 300-400 nm; the thickness of the second intrinsic quantum dot layer 2241 is 300-400 nm; and the thickness of the third intrinsic quantum dot layer 2441 is 300-400 nm.

[0081] As shown in Figure 8 , Figure 8 A back plate structure schematic diagram of an infrared imager 100 provided by the embodiments of the present disclosure. The bottom electrode grid arrangement of the multiple isolation resistors 23 in the detection unit 2 forms a grid common electrode, which is connected with a ground electrode (not shown in Figure 8 ).

[0082] The pixel area refers to the area that receives light, and the pixel area internally includes a pixel electrode, a part of a common electrode, and liquid crystal material between the two.

[0083] The pixel electrode is an independent and isolated transparent electrode (usually using ITO material) located inside each pixel area. As shown in Figure 8 , the electrode in the center of each small square (pixel area) is the pixel electrode, which is the receiving end of the signal and is responsible for carrying the data signal, i.e., image information.

[0084] Referring to Figure 9 , Figure 9 A working principle schematic diagram of an infrared imager 100 provided by the embodiments of the present disclosure.

[0085] The infrared imager 100 further comprises a converging lens 3 and a data acquisition module 4.

[0086] The converging lens 3 is arranged between the imaging object and the detection unit 2, and is used to converge the light rays of the imaging object onto the detection unit 2; the data acquisition module 4 is electrically connected with the signal readout line 13; and the data acquisition module 4 is used to process the photoelectric signal generated by the detection unit 2 in response to the light rays of the imaging object.

[0087] The infrared light emitted by the imaging object first passes through the converging lens 3 and is focused onto the plurality of detection units 2, each of which receives the infrared light focused from its corresponding object point; the quantum dot layer inside the diode detector 22 responds to infrared light of a specific waveband, generates photoelectric effect, and generates photo-generated carriers (electron-hole pairs) in proportion to the light intensity, thereby converting the optical signal into an electrical signal; when reading is required, the thin film transistor 21 acts as a switch and is opened row by row under the control of the gate signal, and the analog voltage signal integrated by each pixel is transmitted out through the signal readout line 13; the data acquisition module 4 is electrically connected with all the signal readout lines 13, and the data acquisition module 4 amplifies and filters the analog voltage signal, and then performs analog-to-digital conversion, rearranges the obtained digital signal according to the pixel position, and finally generates a complete digital infrared image.

[0088] It should be noted that, in this document, relational terms such as“first” and“second”, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms“comprises”,“comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by“comprises a...” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0089] The above description is merely one specific implementation of the present disclosure, which enables a person skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An infrared imager, characterized in that: include: substrate; A plurality of detection units are arranged in an array on one side of the substrate; A single detection unit includes a thin film transistor, a diode detector and an isolation resistor; The thin film transistor at least includes a control terminal and a first terminal, the diode detector is connected between the control terminal and the first terminal of the thin film transistor, and the isolation resistor is connected in parallel with the diode detector; The thin film transistor and the diode detector are configured to be turned on when receiving a first bias voltage and turned off when receiving a second bias voltage; The isolation resistor is used to eliminate leakage current between the plurality of diode detectors.

2. The infrared imager according to claim 1, characterized in that The isolation resistor comprises: a first bottom electrode, a first carrier transport layer, a first quantum dot layer, a second quantum dot layer, a third quantum dot layer, a second carrier transport layer and a first top electrode stacked on one side of the base substrate and in a direction away from the base substrate; Wherein, the first carrier transport layer and the second carrier transport layer are respectively used to transport one of electrons and holes; A plurality of first bottom electrodes are arranged in a grid and connected to a ground electrode, and the leakage current flows into the ground electrode through the first bottom electrodes.

3. The infrared imager according to claim 2, characterized in that: The thin film transistor further includes: a second terminal; The base substrate is also provided with a gate signal line, a bias signal line and a signal readout line; The control terminal of the thin film transistor is electrically connected to the gate signal line, the diode detector is connected between the bias signal line and the first terminal of the thin film transistor, and the second terminal of the thin film transistor is electrically connected to the signal readout line; The gate signal line crosses the bias signal line to separate the plurality of detection units; and the signal readout line is parallel to the bias signal line.

4. The infrared imager according to claim 3, characterized in that The diode detector includes: a second bottom electrode, a third carrier transport layer, a fourth quantum dot layer, a fifth quantum dot layer, a sixth quantum dot layer, a fourth carrier transport layer, and a second top electrode stacked on one side of the substrate and in a direction away from the substrate; Wherein, the second bottom electrode is electrically connected to the control terminal of the thin film transistor; the conductivity of the first bottom electrode is greater than the conductivity of the second bottom electrode; The third carrier transport layer is provided on the same layer as the first carrier transport layer, and the fourth carrier transport layer is provided on the same layer as the second carrier transport layer; The fourth quantum dot layer is arranged in the same layer as the first quantum dot layer, the fifth quantum dot layer is arranged in the same layer as the second quantum dot layer, and the sixth quantum dot layer is arranged in the same layer as the third quantum dot layer.

5. The infrared imager according to claim 1, characterized in that: The detection unit includes a fifth carrier transport layer, a seventh quantum dot layer, an eighth quantum dot layer, a ninth quantum dot layer, a sixth carrier transport layer and a third top electrode shared by the diode detector and the isolation resistor; The diode detector further includes: a third bottom electrode; the isolation resistor further includes: a fourth bottom electrode; Wherein, the fifth carrier transport layer and the sixth carrier transport layer are respectively used to transport one of electrons and holes; A plurality of the fourth bottom electrodes are arranged in a grid and connected to the ground electrode, and the leakage current flows into the ground electrode through the fourth bottom electrodes.

6. The infrared imager according to claim 4, characterized in that: The first top electrode and the second top electrode are integrally formed; or; The first top electrode and the second top electrode are electrically connected.

7. The infrared imager according to claim 4, characterized in that: One of the first quantum dot layer and the third quantum dot layer is an N-type quantum dot layer, and the other is a P-type quantum dot layer; One of the fourth quantum dot layer and the sixth quantum dot layer is an N-type quantum dot layer, and the other is a P-type quantum dot layer; The second quantum dot layer includes: a first intrinsic type quantum dot layer; The fifth quantum dot layer includes: a second intrinsic type quantum dot layer; The first intrinsic type quantum dot layer and the second intrinsic type quantum dot layer generate photoelectric signals in response to different wavelength bands.

8. The infrared imager according to claim 5, characterized in that: One of the seventh quantum dot layer and the ninth quantum dot layer is an N-type quantum dot layer, and the other is a P-type quantum dot layer; The eighth quantum dot layer includes: a third intrinsic type quantum dot layer; The third intrinsic quantum dot layer generates photoelectric signals in response to different wavelength bands.

9. The infrared imager according to claim 7 or 8, characterized in that: The thickness of the first top electrode is 20 nanometers to 40 nanometers; The thickness of the second top electrode is 20 nm to 40 nm; The thickness of the third top electrode is 20 nanometers to 40 nanometers; The thickness of the N-type quantum dot layer is 50 nanometers to 200 nanometers; The thickness of the P-type quantum dot layer is 50 nanometers to 200 nanometers; The thickness of the first intrinsic quantum dot layer is 300 nanometers to 400 nanometers; The thickness of the second intrinsic quantum dot layer is 300 nanometers to 400 nanometers; The thickness of the third intrinsic type quantum dot layer is 300 nanometers to 400 nanometers.

10. The infrared imager according to claim 3, characterized in that: Also includes: A converging lens is provided between the imaging object and the detection unit; the converging lens is used to converge the light of the imaging object onto the detection unit; A data acquisition module is electrically connected to the signal readout line; the data acquisition module is used to process the photoelectric signal generated by the detection unit in response to the light of the imaging object.

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