Infrared photoelectric detector, array and chip based on ion electron hybrid semiconductor

Abstract

The invention belongs to the technical field of photoelectric semiconductor devices, and discloses an infrared photoelectric detector based on an ion electron hybrid semiconductor, an array and a chip. The infrared photoelectric detector comprises a cathode, an anode, a photosensitive layer arranged between the cathode and the anode, an electron transport layer arranged between the cathode and the photosensitive layer, and a hole transport layer arranged between the photosensitive layer and the anode. The ion electron hybrid semiconductor layer is used for changing the work function of the anode and promoting the formation of a potential barrier for blocking injected electrons at an interface between the hole transport layer and the anode; the ion electron hybrid semiconductor layer is arranged between the hole transport layer and the anode; the ion-electron hybrid semiconductor layer comprises an ion-electron hybrid semiconductor material; the ion-electron hybrid semiconductor material is composed of a conjugated polymer main chain with semiconductor characteristics, a side chain capable of conducting ions and two or more counter ions, and has the capability of conducting ions and electrons at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic semiconductor devices, and more specifically, to an infrared photoelectric detector, array and chip based on ion-electron hybrid semiconductors. Background Art

[0002] The basic structure of a photodetector is: electrode, photosensitive layer, electrode. Generally speaking, a photodetector has a PN junction or a Schottky junction. The working mechanism of a photodetector is: incident light triggers the electrons in the valence band of the photosensitive layer to transition to the conduction band to form photogenerated electrons and photogenerated holes. Under the action of the PN junction (or Schottky junction) and an external bias, the photogenerated electrons and photogenerated holes are transmitted in opposite directions and collected to the cathode and anode, thereby generating electrical signals in the circuit.

[0003] In today's photodetectors, functional layers are usually introduced to improve device performance; for example, hole transport layer, electron transport layer, hole collection layer, electron collection layer, hole blocking layer, electron blocking layer and other functional layers. Under light conditions, the movement path of photogenerated electrons in the device is: photosensitive layer, electron transport layer and / or collection layer, cathode; the movement path of photogenerated holes is: photosensitive layer, hole transport layer and / or collection layer, anode. Under dark conditions, the photosensitive layer basically does not generate photogenerated electrons and photogenerated holes, but generally generates dark current; under external bias, the dark current mainly comes from carriers injected from the electrode.

[0004] How to effectively reduce the dark current of the photodetector, thereby improving the detection performance of the photodetector, has become an urgent problem to be solved. Summary of the invention

[0005] In order to effectively reduce the dark current of a photodetector, the present invention provides an infrared photodetector based on an ion-electron hybrid semiconductor.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An infrared photodetector based on ion-electron hybrid semiconductor, comprising a cathode, an anode, a photosensitive layer arranged between the cathode and the anode, an electron transport layer arranged between the cathode and the photosensitive layer, and a hole transport layer arranged between the photosensitive layer and the anode;

[0008] It also includes an ion-electron hybrid semiconductor layer for changing the work function of the anode to form a barrier to the injection of electrons at the interface between the hole transport layer and the anode;

[0009] The ion-electron hybrid semiconductor layer is arranged between the hole transport layer and the anode;

[0010] The ionic-electronic hybrid semiconductor layer includes an ionic-electronic hybrid semiconductor material; the ionic-electronic hybrid semiconductor (HIES) material is composed of a conjugated polymer main chain with semiconductor properties, a side chain capable of conducting ions, and two or more pairs of ions, and has the ability to conduct ions and electrons simultaneously.

[0011] In the present invention, the side chains and counterions can not only adjust the work function and potential barrier of the anode interface, but also dope the conjugated main chain of the material, thereby changing the carrier transport characteristics and energy level structure. This unique dual-functionality enables HIES to achieve precise work function regulation and interface optimization.

[0012] In the present invention, ion-electron hybrid semiconductors (HIES) with different counter ion ratios can be introduced, such as PFN-Br x (BArF4) 1-x 、PFN-(Blm4) x (BArF4) 1-x 、PNDIT-F3N-Br x (BArF4) 1-x 、PNDIT-F3N-(Blm4) x (BArF4) 1-x By changing the ion ratio x, the work function of the anode can be accurately and continuously adjusted, thereby regulating the injection of external carriers under reverse bias voltage; at the same time, the ion-electron hybrid semiconductor (HIES) layer can passivate the interface defects between the anode and the hole transport layer; through the above two effects, the dark current under reverse bias voltage can be suppressed.

[0013] Preferably, the LUMO energy level of the ionic-electron hybrid semiconductor layer is higher than the work function of the anode, and higher than the LUMO energy level of the hole transport layer.

[0014] The LUMO energy level of the ionic electron hybrid semiconductor layer is higher than the work function of the anode and higher than the LUMO energy level of the hole transport layer, resulting in an increase in the potential barrier between the anode and the hole transport layer, thereby effectively blocking external electrons from being injected into the photosensitive layer through the hole transport layer, thereby reducing the dark current in the dark state.

[0015] Preferably, the LUMO energy level of the ionic-electron hybrid semiconductor layer is lower than the work function of the anode, and lower than the LUMO energy level of the hole transport layer.

[0016] In the present invention, since the LUMO energy level of the introduced ionic electron hybrid semiconductor layer is lower than the work function of the anode and lower than the LUMO energy level of the hole transport layer, the potential barrier between the ionic electron hybrid semiconductor layer and the hole transport layer increases, thereby increasing the potential barrier for externally injected electrons from the anode to the hole transport layer, thereby effectively blocking the injection of external electrons, thereby effectively reducing the dark current in the dark state.

[0017] Furthermore, the conjugated polymer main chain and side chain of the ionic-electronic hybrid semiconductor material include but are not limited to the following:

[0018]

[0019] Among them, X - Represents counter ion.

[0020] In the present invention, the ionic-electronic hybrid semiconductor layer is prepared by solution processing, such as spin coating, blade coating, inkjet printing, and the like.

[0021] Preferably, the counter ions include but are not limited to two or more of the following:

[0022] X - =F - , Cl - Br - , I - , CF3SO3 - , Blm4 - ,BArF4 - , HCOO - ,AcO - , TfO - , HO - , Ox 2- ,CO3 2- , SO3 2- , SO4 2- ,PO4 3-

[0023]

[0024] The hole transport layer includes a single layer or multiple layers of hole transport sublayers; the hole transport sublayer includes an organic hole transport material, a bulk heterojunction formed by blending an organic hole transport material and an electron transport material, or an inorganic metal compound.

[0025] The inorganic metal compound includes tungsten oxide, molybdenum oxide, vanadium oxide, chromium oxide, nickel oxide, copper oxide, cuprous oxide, cuprous thiocyanate, copper sulfide, copper iodide, copper phthalocyanine, or a mixture or a composite of the above materials.

[0026] Preferably, the photosensitive layer comprises an organic semiconductor in the form of a single-phase film or a D / A bulk heterojunction blended film, an inorganic semiconductor or a compound semiconductor in the form of a single-phase or quantum dot nanoparticle, or a combination in a mixed form or a thin film stack; wherein D represents an organic donor semiconductor material; A represents an organic acceptor semiconductor material;

[0027] Wherein, the inorganic semiconductor includes Si, Ge, SiGe, CuInS in crystalline or polycrystalline form. x Se 2-x (0≤x≤2), CuInGa(S,Se), PbS, PbI2, PBI3, InGaAs nano-quantum dots, nano-quantum thin films or single-phase films;

[0028] The organic semiconductor comprises an organic blend of one or more organic donor semiconductor materials used as electron donors (D) and one or more organic acceptor semiconductor materials used as electron acceptors (A) to form D / A.

[0029] Wherein, the organic donor semiconductor material comprises: P1, poly[[2,6'-4,8-bis[5-ethylhexylphenyl]benzo[1,2-b and 3,3-b]dithiophene][[3-fluoro-2[(2-ethylhexyl)carbonyl]thiophene[3,4-b]thiophenediyl]] (PTB7-Th), poly[4,8-bis[[2-ethylhexyl]oxy]benzodithiophene-2,6-diyl-ethylhexyl]carbonyl]thiophene- 4,6-diyl] (PTB7), poly[[4,8-bis[5-(2-ethylhexyl)-4-fluoro-2-thieno]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxy-4H,8H-benzo[1,2-c:4,5-c′]dithiophene-1,3-diyl]-2,5-thiophenediyl] (PM6), etc.;

[0030]

[0031] The organic acceptor semiconductor materials include: Y6-BO, Y7, COTIC-4F, IEICO-4F, 2,2'-((12,13-bis(2-butyl)-3,9-heneicosyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2",3":4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]indole-2,10-diyl)bis(6,7-difluoro-4-oxonaphthalene-3(4H)-yl-1(4H)-methylene)dimalononitrile (Z1), PC71BM, PC61BM, etc.

[0032] The present invention also includes a substrate disposed on the side of the anode away from the ion-electron hybrid semiconductor layer, or disposed on the side of the cathode away from the electron transport layer; the substrate is selected from glass, quartz, silicon, silicon oxide or silicon nitride.

[0033] In the present invention, a packaging layer is also included; the packaging layer is used to ensure that the infrared photoelectric detector works stably under various use environments and during the target life. If the infrared photoelectric detector is bottom-incident, this packaging layer does not need to be optically transparent. If the infrared photoelectric detector is top-incident, this packaging layer should be transparent in the working band and the optical transmittance should be above 30%.

[0034] The encapsulation layer can be formed by various vacuum coating methods, such as thermal evaporation, molecular beam coating or plasma sputtering, atomic layer deposition. It can also be prepared by liquid film forming methods, such as drop coating, dip coating, spin coating and various printing methods. In addition to selecting a single material, the encapsulation layer can also be formed by alternating multiple layers of film. In addition to improving the packaging performance, this alternating film structure can also be used to optimize the optical resonant cavity structure of the infrared photodetector in the working band, thereby optimizing its photosensitivity and specific detection rate.

[0035] Commonly used inorganic packaging materials include silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, zirconium oxide, magnesium oxide, zirconium oxide and magnesium fluoride. Commonly used organic packaging materials include polymethyl methacrylate, polyethylene oxide, polystyrene, polyvinyl pyrrolidone, polycarbonate, polyacrylic acid, epoxy resin, polyparaxylene and polysiloxazane.

[0036] In the present invention, the cathode or anode is selected from ITO, gold, silver, titanium, magnesium, aluminum, tungsten, copper, platinum, tin oxide or tungsten oxide.

[0037] The cathode or anode can be formed, for example, by one or more dry processes selected from the group consisting of solution film formation, sol-gel film formation, vacuum thermal evaporation, atomic layer deposition, chemical vapor deposition, electrodeposition, and anodization.

[0038] The material of the electron transport layer includes an organic compound 1, an inorganic compound 1, or a combination thereof;

[0039] Wherein, the organic compound 1 includes fullerene and its derivatives, 4,7-diphenyl-1,10-phenanthroline, polyethyleneimine, polyethoxyethyleneimine, 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, [9,9-dioctylfluorene-9,9-bis(N,N-dimethylaminopropyl)fluorene], bromo-[9,9-dioctylfluorene-9,9-bis(N,N-dimethylaminopropyl)fluorene], 8-hydroxyquinoline lithium, 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene, bis(2-methyl-8-quinolinol)-4-(phenylphenol)aluminum, 1,3,5-tri[(3-pyridyl)-phenyl-3-yl]benzene, naphthalene diimide bromide, or a mixture or a composite of the above materials;

[0040] The inorganic compound 1 includes zinc oxide, tin oxide, aluminum-doped zinc oxide, magnesium-doped zinc oxide, gallium-doped zinc oxide, titanium oxide, tantalum oxide, zinc sulfide, chromium sulfide, or a mixture or composite of the above materials.

[0041] The preparation of the electron transport layer and the hole transport layer are independently selected from one or more of solution film formation, sol-gel film formation, vacuum thermal evaporation, atomic layer deposition, chemical vapor deposition, electrodeposition, and anodization.

[0042] In the present invention, the infrared photodetector based on ion-electron hybrid semiconductor can be selected from a flip-chip structure or a face-up structure;

[0043] The inverted structure includes, from bottom to top, a substrate, a cathode close to the substrate, an electron transport layer, a photosensitive layer, a hole transport layer, an ion-electron hybrid semiconductor layer, an anode and an encapsulation layer.

[0044] The upright structure includes, from bottom to top, a substrate, an anode close to the substrate, an ion-electron hybrid semiconductor layer, a hole transport layer, a photosensitive layer, an electron transport layer, a cathode and a packaging layer.

[0045] An infrared photoelectric detector array based on ion-electron hybrid semiconductor, the infrared photoelectric detector array comprises a plurality of pixels, and the pixels comprise the infrared photoelectric detector based on ion-electron hybrid semiconductor.

[0046] Preferably, the infrared photodetector array further comprises a substrate; the substrate comprises a pixel readout circuit composed of silicon-based complementary metal oxide semiconductor transistors or thin film transistors.

[0047] An infrared photodetector focal plane array imaging chip based on ion-electron hybrid semiconductor comprises the infrared photodetector array based on ion-electron hybrid semiconductor.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The present invention introduces an ion-electron hybrid semiconductor layer for changing the work function of the anode between the hole transport layer and the anode. By changing the ion proportion x, the work function of the anode can be accurately and continuously adjusted, thereby regulating the injection of external carriers under a reverse bias voltage; at the same time, the ion-electron hybrid semiconductor (HIES) layer can passivate the interface defects between the anode and the hole transport layer; through the above two effects, the dark current under the reverse bias voltage is suppressed, the signal-to-noise ratio is improved, and the imaging effect of the infrared photodetector focal plane array imaging chip is optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the device structure of the infrared photoelectric detector provided by the present invention.

[0051] Figure 2 It is a schematic diagram of continuously adjusting the work function by changing the ion ratio in Example 1.

[0052] Figure 3 This is a diagram showing the working principle of the ionic-electronic hybrid semiconductor layer introduced in Example 1.

[0053] Figure 4 It is a comparison chart of capacitance data of the infrared photodetector with and without HIES in Example 1.

[0054] Figure 5 This is a comparison chart of the external quantum efficiency of infrared photodetectors of the ion-electron hybrid semiconductor (HIES) of Example 1 at different ion ratios.

[0055] Figure 6 This is a comparison diagram of the dark current density of the infrared photodetector of the ion-electron hybrid semiconductor (HIES) of Example 1 at different ion ratios.

[0056] Figure 7 This is a comparison chart of the external quantum efficiency of the infrared photodetector with and without HIES in Example 2.

[0057] Figure 8 It is a comparison diagram of the dark current density of the infrared photodetector with and without HIES in Example 2.

[0058] Fig. 9 This is a comparison chart of the external quantum efficiency of the infrared photodetector with and without HIES in Example 3.

[0059] Fig.10 It is a comparison diagram of dark current density of the infrared photodetector with and without HIES in Example 3.

[0060] Fig.11This is a comparison chart of the external quantum efficiency of the infrared photodetector with and without HIES in Example 4.

[0061] Fig.12 It is a comparison diagram of the dark current density of the infrared photodetector with and without HIES in Example 4.

[0062] Fig.13 This is a comparison chart of the external quantum efficiency of the infrared photodetector with and without HIES in Example 5.

[0063] Fig.14 It is a comparison diagram of the dark current density of the infrared photodetector with and without HIES in Example 5.

[0064] Fig.15 It is the imaging effect diagram of the infrared photodetector with and without HIES in Example 6.

[0065] Fig.16 This is a side view of the device structure of an infrared photodetector array provided in Example 7.

[0066] In the figure, 1-cathode, 2-electron transport layer, 3-photosensitive layer, 4-hole transport layer, 5-ion-electron hybrid semiconductor layer, 6-anode, 7-packaging layer, 8-pixel readout circuit, 9-substrate, 10-pixel. DETAILED DESCRIPTION

[0067] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention is described in detail below in combination with the drawings and specific implementation methods.

[0068] It should be understood that when used in this specification, the terms "include" and "comprising" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0069] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0070] It should be further understood that the term “and / or” used in the specification of the present invention refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0071] Example 1

[0072] This embodiment provides an infrared photodetector with a flip-chip structure, such as Figure 1 As shown, the specific device structure is glass / indium tin oxide (ITO) electrode / zinc oxide (ZnO) / photosensitive layer / molybdenum oxide (MoO x ) / PFN-Br x (BArF4) 1-x / Silver (Ag) electrode;

[0073] Among them, glass is used as the substrate, ITO is used as the transparent bottom cathode, ZnO is used as the electron transport layer, the photosensitive layer is a double-layer structure composed of lead sulfide colloidal quantum dots (PbS CQDs) and JD40-BDD20, and MoO x As a hole transport layer, PFN-Br x (BArF4) 1-x As the HIES layer, Ag is used as the top reflective electrode. The work function of the Ag electrode increases with the addition of the HIES layer Br. - The ion ratio x changes, such as Figure 2 As shown in , the electron injection from the Ag electrode under reverse bias voltage changes. Figure 3 As shown in Figure 2, when the value of x increases, the work function of the Ag electrode decreases and is closer to that of MoO x The LUMO energy level distance increases, and the Fermi level of the Ag electrode is close to that of MoO x The electron momentum mismatch at the LUMO of the Ag electrode becomes more serious, and the participation of phonons (δ+) is required to realize the transfer of electrons between energy levels, so that the electrons move from the Ag electrode to the MoO x At the same time, according to the capacitance-frequency test (such as Figure 4 As shown in the figure, the junction capacitance and defect density of the device decrease with the addition of the HIES layer, indicating that the HIES layer passivates the MoO x Interface defects between Ag electrode and Ag electrode.

[0074] The infrared photodetector provided in this embodiment is compared with a standard device (ITO / ZnO / photosensitive layer / MoO x / Ag) external quantum efficiency (EQE) and dark current density are compared. The corresponding EQE and dark current experimental data are obtained through testing, such as Figure 5 , Figure 6 As shown. Figure 5As shown in the figure, in the infrared photodetector provided by the present invention, due to the HIES passivation of MoO x The interface defects between the Ag electrode and the Ag electrode reduce the electron-hole recombination caused by the defects, thereby improving the EQE of the device; at the same time, it can be seen that the change in the value of x will not have a significant effect on the EQE of the device. Figure 6 As shown in the figure, due to the passivation of MoO x The interface defects between the Ag electrode and MoO reduce the generation of trap-assisted current, thereby reducing the dark current density of the device; at the same time, the dark current density decreases with the increase of x value, which proves that the Fermi level of the Ag electrode and MoO x The greater the LUMO difference, the greater the mismatch in electron momentum, and the more difficult it is for electrons to move from the Ag electrode to the MoO x The dark current density of the device is reduced by the transfer of the passivation mechanism and the energy level mechanism. Since the performance of the device is affected by the passivation mechanism and the energy level mechanism at the same time, the minimum dark current value is within the range of x = 0.7 to 1.0.

[0075] Example 2

[0076] This embodiment provides an infrared photodetector with a flip-chip structure, such as Figure 1 As shown, its structure is Glass / ITO / ZnO / photosensitive layer / MoO x / PFN-Br 0.8 (BArF4) 0.2 / Ag; glass is used as substrate, ITO as transparent bottom electrode, ZnO as electron transport layer, photosensitive layer is a double-layer structure composed of PbS CQDs and JD40-BDD20:IEICO-4F, PFN-Br 0.8 (BArF4) 0.2 As the HIES layer, Ag acts as the top reflective electrode.

[0077] The infrared photodetector provided in this embodiment is compared with a standard device (ITO / ZnO / photosensitive layer / MoO x / Ag) are compared with the EQE and dark current density. By testing the corresponding EQE and dark current experimental data, we can get Figure 7 , Figure 8 .in, Figure 7 is the EQE data measured under zero bias. Figure 7 It can be seen that the present invention passivates MoO x The interface defects between the MoO2 and Ag electrodes reduce the electron-hole recombination caused by the defects, thereby improving the EQE of the device. xThe interface defects between the Ag electrode and the Ag electrode reduce the generation of trap-assisted current; at the same time, the HIES layer leads to a decrease in the work function of the Ag electrode, and the Fermi level of the Ag electrode is close to that of MoO x The LUMO difference becomes larger, the electron momentum does not match, and the electrons move from the Ag electrode to the MoO x The barrier to transfer becomes larger. Under the simultaneous action of these two mechanisms, the dark current density of the device is greatly reduced compared to the standard device, such as Figure 8 shown.

[0078] Example 3

[0079] This embodiment provides an infrared photodetector with a flip-chip structure, such as Figure 1 As shown, its structure is Glass / ITO / ZnO / photosensitive layer / MoO x / PFN-Br 0.9 (BArF4) 0.1 / Ag; glass is used as substrate, ITO is used as transparent bottom electrode, ZnO is used as electron transport layer, the photosensitive layer is PTB7-Th:Y-QC4F blend film, PFN-Br 0.9 (BArF4) 0.1 As the HIES layer, Ag acts as the top reflective electrode.

[0080] The infrared photodetector provided in this embodiment is compared with a standard device (ITO / ZnO / photosensitive layer / MoO x / Ag) are compared with the EQE and dark current density. By testing the corresponding EQE and dark current experimental data, we can get Fig. 9 , Fig.10 .in, Fig. 9 is the EQE data measured under zero bias. Fig. 9 It can be seen that in the infrared photodetector provided by the present invention, since the HIES layer passivates the MoO x The interface defects between the MoO2 and Ag electrodes reduce the electron-hole recombination caused by the defects, thereby improving the EQE of the device. x The interface defects between the Ag electrode and the Ag electrode reduce the generation of trap-assisted current; at the same time, the HIES layer leads to a decrease in the work function of the Ag electrode, and the Fermi level of the Ag electrode is close to that of MoO x The LUMO difference becomes larger, the electron momentum does not match, and the electrons move from the Ag electrode to the MoO x The transfer barrier becomes larger; under the simultaneous action of these two mechanisms, the dark current density of the device is significantly reduced compared with the standard device, such as Fig.10 shown.

[0081] Example 4

[0082] This embodiment provides an infrared photodetector with a flip-chip structure, such as Figure 1 As shown, its structure is Glass / ITO / ZnO / photosensitive layer / MoO x / PFN-Br 0.9 (BArF4) 0.1 / Ag; glass is used as substrate, ITO as transparent bottom electrode, ZnO as electron transport layer, photosensitive layer is P1:Y7 blend film, PFN-Br 0.9 (BArF4) 0.1 As the HIES layer, Ag acts as the top reflective electrode.

[0083] The infrared photodetector provided in this embodiment is compared with a standard device (ITO / ZnO / photosensitive layer / MoO x / Ag) are compared with the EQE and dark current density. By testing the corresponding EQE and dark current experimental data, we can get Fig.11 , Fig.12 .in, Fig.11 is the EQE data measured at -1V bias voltage. Fig.11 It can be seen that the EQE of the infrared photodetector device provided by the present invention is basically consistent with that of the standard device. x The interface defects between the Ag electrode and the Ag electrode reduce the generation of trap-assisted current; at the same time, the HIES layer leads to a decrease in the work function of the Ag electrode, and the Fermi level of the Ag electrode is close to that of MoO x The LUMO difference becomes larger, the electron momentum does not match, and the electrons move from the Ag electrode to the MoO x The transfer barrier becomes larger; under the simultaneous action of these two mechanisms, the dark current density of the device is significantly reduced compared with the standard device, such as Fig.12 shown.

[0084] Example 5

[0085] This embodiment provides an infrared photodetector with a flip-chip structure, such as Figure 1 As shown, its structure is Glass / ITO / ZnO / photosensitive layer / MoO x / PFN-Br 0.7 (BArF4) 0.3 / Ag; glass is used as substrate, ITO is used as transparent bottom electrode, ZnO is used as electron transport layer, the photosensitive layer is PTB7-Th:Y-QC4F blend film, PFN-Br 0.7 (BArF4) 0.3 As the HIES layer, Ag acts as the top reflective electrode.

[0086] The infrared photodetector provided in this embodiment is compared with a standard device (ITO / ZnO / photosensitive layer / MoOx / Ag) are compared with the EQE and dark current density. By testing the corresponding EQE and dark current experimental data, we can get Fig.13 , Fig.14 .in, Fig.13 is the EQE data measured under zero bias. Fig.13 It can be seen that in the infrared photodetector provided by the present invention, since the HIES layer passivates the MoO x The interface defects between the MoO2 and Ag electrodes reduce the electron-hole recombination caused by the defects, thereby improving the EQE of the device. x The interface defects between the Ag electrode and the Ag electrode reduce the generation of trap-assisted current; at the same time, the HIES layer leads to a decrease in the work function of the Ag electrode, and the Fermi level of the Ag electrode is close to that of MoO x The LUMO difference becomes larger, the electron momentum does not match, and the electrons move from the Ag electrode to the MoO x The transfer barrier becomes larger; under the simultaneous action of these two mechanisms, the dark current density of the device is significantly reduced compared with the standard device, such as Fig.14 shown.

[0087] Example 6

[0088] The device structure of the infrared photodetector provided in this embodiment is as follows: CMOS / metal layer / ZnO / photosensitive layer / MoO x / PFN-Br 0.8 (BArF4) 0.2 / 15nm Ag; the substrate is integrated with a pixel readout circuit of a CMOS transistor, the metal layer is the bottom gold (Au) electrode connected to the pixel readout circuit, ZnO is the electron transport layer, the photosensitive layer is a double-layer structure composed of PbS CQDs and JD40-BDD20:IEICO-4F, MoO x As a hole transport layer, PFN-Br 0.8 (BArF4) 0.2 As the HIES layer, 15 nm thin Ag was adopted as the top transparent electrode.

[0089] This embodiment also provides a standard device for comparison, and its device structure is as follows: CMOS / metal layer / ZnO / photosensitive layer / MoO3 / 15nm Ag; wherein the substrate is integrated with a pixel readout circuit of a CMOS transistor, the metal layer is the bottom Au electrode connected to the readout circuit, ZnO is the electron transport layer, the photosensitive layer is a double-layer structure composed of PbS CQDs and JD40-BDD20:IEICO-4F, and MoO x As a hole transport layer, Ag (15 nm) was used as the top transparent electrode.

[0090] In this embodiment, incident light is injected from the top electrode, and the light is absorbed in the photosensitive layer to form excitons. After the excitons dissociate at the interface, the photogenerated electrons are collected from the ZnO to the pixel readout circuit of the CMOS transistor in the substrate, and the photogenerated holes are collected from the MoO x transferred to the Ag electrode.

[0091] After connecting to the external driving circuit, the pixel readout circuit of the CMOS transistor reads the electrons of each pixel in turn under the external timing drive, forms the electrical signal of each pixel, and finally realizes imaging. In the standard device, each pixel works under reverse bias, and the higher dark current leads to a low signal-to-noise ratio (SNR) and poor image contrast, such as Fig.15 As shown in part (a).

[0092] The imaging effect measured by the infrared photoelectric detector described in this embodiment is as follows: Fig.15 As shown in part (b) of the figure. Since the infrared photodetector provided in this embodiment uses the HIES layer to passivate the MoO x The interface defects between the Ag electrode and the Ag electrode reduce the electron-hole recombination and trap-assisted current caused by the defects; at the same time, the work function of the Ag electrode is reduced, and an additional barrier for external injection under reverse bias is constructed. This improves the EQE of a single pixel, reduces the dark current density of a single pixel under reverse bias, improves the SNR, and improves the contrast of the image. Fig.15 shown.

[0093] Example 7

[0094] Based on the infrared photoelectric detectors provided in the above embodiments, an infrared photoelectric detector array is also provided, such as Fig.16 As shown, the infrared photodetector array includes a plurality of pixels 10, and the pixels 10 include the infrared photodetectors described in the above embodiment.

[0095] In this embodiment, the infrared photodetector array further includes a substrate 9; the substrate 9 includes a pixel readout circuit 8 composed of a silicon-based complementary metal oxide semiconductor transistor or a thin film transistor.

[0096] From bottom to top, the infrared photodetector array includes a pixel readout circuit 9 made of silicon-based complementary metal oxide semiconductor transistors (MOSFET) on a single crystal silicon substrate, and each pixel readout circuit is connected to a cathode 1 that defines the pixel size. Arranged on the cathode are an electron transport layer 2, a photosensitive layer 3, a hole transport layer 4, an ion-electron hybrid semiconductor layer 5, an anode 6, and a packaging layer 7. From the electron transport layer 2, the photosensitive layer 3, the hole transport layer 4, the ion-electron hybrid semiconductor layer 5, the anode to the packaging layer 7, they are all continuous structures in the entire array area.

[0097] The infrared organic photoelectric sensor array of this embodiment is composed of N×M pixels. The size of the pixel 10 is 25 μm, and the number of pixels is 1×256 or 1×512.

[0098] It should be noted that the infrared photodetector array can be an inverted structure, and can adopt top incidence or bottom incidence. The device structure of the infrared photodetector array can also adopt a normal structure. Regardless of whether the device structure of the infrared photodetector adopts an inverted structure or a normal structure, or adopts top incidence or bottom incidence, it belongs to the protection scope of the present invention.

[0099] For bottom-incident infrared photodetectors, the cathode or anode near the substrate is transparent or partially transparent in the required wavelength range, and the optical transmittance of the electrode is higher than 30%. The cathode or anode near the substrate can be a transparent metal oxide (such as indium tin oxide, zinc oxide and aluminum-doped zinc oxide, etc.), or a nitride (such as titanium nitride) and the corresponding metal oxynitride.

[0100] For top-incident infrared photodetectors, the cathode or anode near the substrate can be used to reflect incident light in the required wavelength range to optimize the photosensitivity in a specific band. By selecting a suitable metal material, the required conductivity and optical reflectivity can be obtained at the same time. In addition, the anode or cathode near the encapsulation layer is transparent or partially transparent in the required wavelength range, and the optical transmittance of the electrode is higher than 30%. And the encapsulation layer is also required to be transparent or translucent.

[0101] Example 8

[0102] This embodiment also provides an infrared photodetector focal plane array imaging chip based on ion-electron hybrid semiconductor, and the infrared photodetector focal plane array imaging chip includes the infrared photodetector array described in Embodiment 7. The infrared photodetector focal plane array imaging chip is used for performing infrared photosensitive imaging.

[0103] The infrared photodetector focal plane array imaging chip described in this embodiment can be applied in the following aspects:

[0104] 1. It can be an industrial camera used to detect and identify defects, foreign matter, cracks and other problems on the surface of materials.

[0105] 2. It can also be used in medical diagnosis. Infrared light can penetrate the skin and other biological tissues, providing deeper details and resolution.

[0106] 3. It can also be used in food safety, specifically to detect contaminants, ingredients and quality in food.

[0107] 4. It can also be used in environmental monitoring to help monitor environmental parameters such as atmospheric pollutants, water quality and soil moisture content.

[0108] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An infrared photodetector based on ion-electron hybrid semiconductor, characterized in that: It includes a cathode, an anode, a photosensitive layer arranged between the cathode and the anode, an electron transport layer arranged between the cathode and the photosensitive layer, and a hole transport layer arranged between the photosensitive layer and the anode; It also includes an ion-electron hybrid semiconductor layer for changing the work function of the anode to form a barrier to the injection of electrons at the interface between the hole transport layer and the anode; The ion-electron hybrid semiconductor layer is arranged between the hole transport layer and the anode; The ionic-electronic hybrid semiconductor layer comprises an ionic-electronic hybrid semiconductor material; the ionic-electronic hybrid semiconductor material is composed of a conjugated polymer main chain with semiconductor properties, a side chain capable of conducting ions, and two or more pairs of ions, and has the ability to conduct ions and electrons simultaneously.

2. The infrared photodetector based on ion-electron hybrid semiconductor according to claim 1, characterized in that: The LUMO energy level of the ion-electron hybrid semiconductor layer is higher than the work function of the anode and higher than the LUMO energy level of the hole transport layer.

3. The infrared photodetector based on ion-electron hybrid semiconductor according to claim 1, characterized in that: The LUMO energy level of the ion-electron hybrid semiconductor layer is lower than the work function of the anode and lower than the LUMO energy level of the hole transport layer.

4. The infrared photodetector based on ion-electron hybrid semiconductor according to any one of claims 2 or 3, characterized in that: The conjugated polymer main chain and side chain of the ionic-electronic hybrid semiconductor material include but are not limited to the following: Among them, X - Represents counter ion.

5. The infrared photodetector based on ion-electron hybrid semiconductor according to claim 4, characterized in that: The counter ions include but are not limited to two or more of the following: X - =F - ,Cl - ,Br - ,I - ,CF3SO3 - ,BIm4 - ,BArF4 - ,HCOO - ,AcO - ,TfO - ,HO - ,Ox 2- ,CO3 2- ,SO3 2- ,SO4 2- ,PO4 3- 6. The infrared photodetector based on ion-electron hybrid semiconductor according to any one of claims 2 or 3, characterized in that: The hole transport layer includes a single layer or multiple layers of hole transport sublayers; the hole transport sublayer includes an organic hole transport material, a bulk heterojunction formed by blending an organic hole transport material and an electron transport material, or an inorganic metal compound.

7. The infrared photodetector based on ion-electron hybrid semiconductor according to claim 1, characterized in that: The photosensitive layer comprises an organic semiconductor in the form of a single-phase film or a D / A bulk heterojunction blended film, an inorganic semiconductor or a compound semiconductor in the form of a single-phase or quantum dot nanoparticle, or a combination in a mixed form or a thin film stack; wherein D represents an organic donor semiconductor material; A represents an organic acceptor semiconductor material; Wherein, the inorganic semiconductor includes Si, Ge, SiGe, CuInS in crystalline or polycrystalline form. x Se 2-x (0≤x≤2), CuInGa(S,Se), PbS, PbI2, PBI3, InGaAs nano-quantum dots, nano-quantum thin films or single-phase films; The organic semiconductor comprises an organic blend of one or more organic donor semiconductor materials used as electron donors (D) and one or more organic acceptor semiconductor materials used as electron acceptors (A) to form D / A.

8. An infrared photodetector array based on ion-electron hybrid semiconductor, characterized in that: The infrared photodetector array includes a plurality of pixels, and the pixels include the infrared photodetector based on ion-electron hybrid semiconductor as described in claim 1.

9. The infrared photodetector array based on ion-electron hybrid semiconductor according to claim 8, characterized in that: The infrared photodetector further comprises a substrate; the substrate comprises a pixel readout circuit composed of a silicon-based complementary metal oxide semiconductor transistor or a thin film transistor.

10. An infrared photodetector focal plane array imaging chip based on ion-electron hybrid semiconductor, characterized in that: It comprises an infrared photodetector array based on ionic-electronic hybrid semiconductor as described in claim 8.

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