A visual light signal detection device and equipment based on light regeneration gain mechanism

Abstract

The application discloses a visual light signal detection device and equipment based on a light regeneration gain mechanism. The visual light signal detection device sequentially comprises a transparent substrate, a transparent anode, a light detection unit, at least one light emitting unit, an electron injection layer and a cathode. The light detection unit sequentially comprises a hole blocking layer, a first electron transport layer and a photoactive layer. The photoactive layer is blended from TAPC and fullerene. The fullerene is C 60 or C 70 . The light emitting unit sequentially comprises a hole transport layer, a light emitting layer and a second electron transport layer. The light emitting layer takes an excimer as a host and takes a phosphor material as a guest. The photoelectric current at the anode is gained, the detection sensitivity is high, the detection of weak light signals is facilitated, the image of the light source is directly imaged on the device, and the simplification of the structure of the detection equipment is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of optical signal detection, and in particular to a visualized optical signal detection device and equipment based on an optical regeneration gain mechanism. Background Art

[0002] As a core component of optoelectronics, photodetectors play a vital role in communications, sensing, imaging, and energy. However, despite significant advances in photodetection technology in recent years, existing detectors still face numerous challenges and limitations in practical applications. For example, low sensitivity hinders detection performance in low-light environments. Multiplication-type photodetectors (such as photomultiplier tubes and avalanche photodiodes) have been widely used in low-light detection, single-photon detection, and high-precision measurement due to their high sensitivity and internal gain characteristics. However, despite their significant performance advantages, these detectors still have several shortcomings that need to be addressed in practical applications. First, multiplication-type photodetectors are often associated with high noise levels, particularly dark current and excess noise, which limits their performance in low signal-to-noise ratio environments. Second, despite their fast response speed, they can still be limited by their gain-bandwidth product in ultra-high frequency applications. Furthermore, these detectors are large in size and consume high power, making them difficult to meet the demands of modern miniaturized and low-power devices. Finally, multiplication-type photodetectors are expensive to manufacture and are prone to gain saturation or damage under high-intensity conditions, limiting their dynamic range and lifetime. Furthermore, existing photodetectors are unable to directly display light source images on the device, primarily due to limitations in their core functionality and physical mechanisms. As unidirectional photoelectric conversion devices, detectors can only convert light signals into electrical signals. They lack active light-emitting components (such as pixelated light-emitting units) and optical-to-electrical-to-optical bidirectional conversion capabilities, making them incapable of autonomously generating visible light images. More importantly, their output signals are analog or digital electrical signals, requiring external processing circuits and display devices (such as screens) for image reconstruction, limiting their real-time performance and integration. Furthermore, issues such as insufficient dynamic range, noise interference, and temperature sensitivity can further degrade the output signal quality, indirectly impacting the accuracy and clarity of the final image. Therefore, in-depth research addressing these shortcomings and exploring new materials, structures, mechanisms, and processes is crucial for further improving the performance of multiplication-type photodetectors and achieving visualization. Summary of the Invention

[0003] In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of the present invention is to provide a visual optical signal detection device based on a light regeneration gain mechanism. Under the continuous illumination of the light source to be measured, light regeneration occurs cyclically in the device, and the self-generated photocurrent continues to increase, so that the photocurrent at the anode is gained. At the same time, the dark current is low and the detection sensitivity is high, which is conducive to the detection of weak light signals. No additional display unit is required, and the image of the light source is directly imaged on the visual optical signal detection device based on the light regeneration gain mechanism, which is conducive to the simplification of the detection equipment structure.

[0004] Another object of the present invention is to provide a visual optical signal detection device based on an optical regeneration gain mechanism, which can achieve visualization without the need for an additional display unit and has a simple device structure.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention provides a visual optical signal detection device based on an optical regeneration gain mechanism, which comprises a transparent substrate, a transparent anode, a light detection unit, at least one light-emitting unit, an electron injection layer, and a cathode in sequence;

[0007] The light detection unit includes a hole blocking layer, a first electron transport layer, and a photoactive layer in sequence; the photoactive layer is formed by mixing TAPC (the full name of which is 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline]) and fullerene; the fullerene is C 60 (The full name in Chinese is Fullerene C 60 ) or C 70 (The full name in Chinese is Fullerene C 70 );

[0008] The light-emitting unit includes a hole transport layer, a light-emitting layer, and a second electron transport layer in sequence; the light-emitting layer uses an exciplex as a host and a phosphorescent material as a guest;

[0009] When the visual optical signal detection device is working, under the illumination of the light source to be measured and the action of forward bias, the photoactive layer absorbs incident photons to generate photogenerated electrons and photogenerated holes; the photogenerated electrons drift to the anode to form an incident photocurrent, and the photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate self-generated photons; a part of the self-generated photons is emitted from the transparent substrate, forming an image of the light source on the visual optical signal detection device; the other part of the self-generated photons are absorbed by the photoactive layer and photoregeneration occurs: the photoactive layer absorbs self-generated photons to generate self-generated photogenerated electrons and self-generated photogenerated holes, the self-generated photogenerated electrons form a self-generated photocurrent at the anode, and the self-generated photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate new self-generated photons; under the continuous illumination of the light source to be measured, the photoactive layer continuously absorbs incident photons to drive the light-emitting layer to generate self-generated photons, photoregeneration continues to occur, the number of self-generated photons continues to increase, and the self-generated photocurrent continues to increase, achieving photocurrent gain.

[0010] Preferably, in the photoactive layer, the mass concentration of TAPC is 5 wt% to 50 wt%; and the thickness of the photoactive layer is 50 to 200 nm.

[0011] Preferably, the exciplex is formed by blending mCBP (full name in Chinese: 3,3'-di(N-carbazolyl)-1,1'-biphenyl) and PO-T2T (full name in Chinese: 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine) in a mass ratio of 1:(0.8-1.2).

[0012] Preferably, the phosphorescent material is FIrpic (full name in Chinese: bis(4,6-difluorophenylpyridine-N,C2)picolinyliridium); in the light-emitting layer, the mass concentration of the phosphorescent material is 6% to 30%.

[0013] Preferably, the hole blocking layer is ZnO (full name in Chinese: zinc oxide) or BCP (full name in Chinese: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), and has a thickness of 10-50 nm.

[0014] Preferably, the hole transport layer has a three-layer structure to reduce charge loss, specifically including a TAPC layer, a TCTA (full name in Chinese: tris(4-carbazol-9-ylphenyl)amine) layer and an mCBP layer; more preferably, the thickness of the TAPC layer is 5~60nm, the thickness of the TCTA layer is 3~10nm; and the thickness of the mCBP layer is 3~10nm.

[0015] Preferably, when more than two light-emitting units are included, a connecting layer is provided between the light-emitting units; more preferably, the connecting layer includes a Liq (full name in Chinese: 8-hydroxyquinoline lithium) layer with a thickness of 1.5 to 2.5 nm; an Al layer with a thickness of 0.5 to 1.5 nm and a HAT-CN (full name in Chinese: 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene) layer with a thickness of 5 to 20 nm.

[0016] Preferably, the transparent substrate is glass, quartz, polyethylene terephthalate (PET) or polyimide (PI).

[0017] Preferably, the material of the first electron transport layer is C 60 or C 70 ;Thickness is 10~30 nm.

[0018] Preferably, the material of the second electron transport layer is PO-T2T, BmPyPb, Bphen, TmPyPb, or TPBi; and the thickness is 40-80 nm.

[0019] Preferably, the material of the electron injection layer is Liq; the thickness is 1.5-2.5 nm.

[0020] The present invention also provides a visual optical signal detection device based on the optical regeneration gain mechanism, comprising a DC power supply, a current measuring unit and the visual optical signal detection device based on the optical regeneration gain mechanism; the current measuring unit is used to measure the photocurrent at the transparent anode.

[0021] The principle of the present invention is:

[0022] In the present invention's visual optical signal detection device based on the photoregeneration gain mechanism, when illuminated by a measured light source and under applied bias, the photoactive layer absorbs incident photons to generate excitons, which then separate into incident photogenerated electrons and incident photogenerated holes. The incident photogenerated electrons drift to the anode and are collected to form a photocurrent, referred to as the incident photocurrent. Meanwhile, the incident photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate new photons, referred to as self-generated photons. Like incident photons, self-generated photons are absorbed by the photoactive layer, generating additional photocurrent, referred to as the self-generated photocurrent. The self-generated photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate new self-generated photons, a process referred to as photoregeneration. Clearly, this photoregeneration process occurs cyclically. Under continuous illumination from the measured light source, the photoactive layer continuously absorbs incident photons, driving the light-emitting layer to generate more self-generated photons, resulting in a continuous increase in the number of self-generated photons. However, because the device's photoelectric conversion efficiency and the active layer's absorption rate of self-generated photons cannot reach 100%, the rate of increase in self-generated photons decreases over time, implying a maximum number of self-generated photons. When the number of self-generated photons reaches its maximum, the device reaches steady-state, where the total photocurrent is the sum of the incident photocurrent generated by the active layer and the self-generated photocurrent, ultimately exhibiting a large photocurrent gain. Furthermore, under illumination and applied bias, the photoactive layer cannot fully absorb the self-generated photons generated by the light-emitting unit, resulting in some self-generated photons being emitted from the anode. Furthermore, in a dark environment, the device's ultra-low dark current is insufficient to drive the light-emitting unit to emit light. When a light source with a specific shape shines on the device, the illuminated areas drive the light-emitting unit to generate self-generated photons, while unilluminated areas do not generate photons. This creates an image of the light source on the device surface, allowing direct observation of the light source's shape. The design of the photoactive layer of the present invention requires a balanced ratio between the number of absorbed photons and the number of unabsorbed photons emitted from the anode, ensuring both photocurrent gain and sufficient light image intensity. This can be achieved by selecting specific materials and thicknesses. Both photocurrent gain and light image intensity can also be controlled by adjusting the number of light-emitting units, the material of the light-emitting layer, and the thickness of the light-emitting layer.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] (1) In the visual optical signal detection device based on the optical regeneration gain mechanism of the present invention, the photoelectrons collected by the anode include the incident photoelectrons generated by the incident light in the photoactive layer, and also include part of the self-generated photoelectrons generated by the optical regeneration, thereby achieving photocurrent gain, which is particularly suitable for the detection of weak light sources; another part of the self-generated photoelectrons generated by the luminescent layer is emitted from the anode to form an image of the light source on the device, and visualization can be achieved without the need for an additional display screen.

[0025] (2) The visual optical signal detection device based on the optical regeneration gain mechanism of the present invention realizes the gain of photocurrent and improves the detection sensitivity through the design of the device, especially the material selection and thickness design of the photoactive layer and the design of the light-emitting unit, and at the same time realizes the visual detection of the light source.

[0026] (3) In the visual optical signal detection device based on the optical regeneration gain mechanism of the present invention, the photocurrent gain in the device does not need to rely on the tunneling injection of external charges. The design of the hole blocking layer and the hole transport layer (which have a blocking effect on electrons) can hinder the injection of external charges, thereby reducing the dark current of the device and improving the detection sensitivity.

[0027] (4) The visual optical signal detection device based on the optical regeneration gain mechanism of the present invention can form an image of the light source on the device without the need for an additional display screen, which is conducive to simplifying the device structure and achieving miniaturization of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of a visualized optical signal detection device based on an optical regeneration gain mechanism according to an embodiment of the present invention.

[0029] Figure 2 Schematic diagram of the working mechanism of a visualized optical signal detection device based on an optical regeneration gain mechanism according to an embodiment of the present invention.

[0030] Figure 3 This is the normalized absorption spectrum of the photoactive layer of the visualized optical signal detection device based on the optical regeneration gain mechanism of Example 1 of the present invention.

[0031] Figure 4 This is the electroluminescence spectrum of the light-emitting layer in the visualized optical signal detection device based on the optical regeneration gain mechanism of Example 1 of the present invention.

[0032] Figure 5 This is a graph showing the external quantum efficiency of a visualized optical signal detection device based on an optical regeneration gain mechanism according to Example 1 of the present invention.

[0033] Figure 6 This is a dark current curve diagram of the visualized optical signal detection device based on the optical regeneration gain mechanism according to Example 1 of the present invention.

[0034] Figure 7 (a) and (b) are respectively the normalized transient photocurrent response (Jt curve) and electroluminescence (EL) characteristic curve of the visualized optical signal detection device based on the optical regeneration gain mechanism of an embodiment of the present invention under the illumination of an LED with a pulse frequency of 100 Hz and a peak of 535 nm.

[0035] Figure 8 for Figure 7 Characteristic diagram showing the direct relationship between transient photocurrent and electroluminescence intensity.

[0036] Figure 9 : is the normalized absorption spectrum of the photoactive layer of the visualized optical signal detection device based on the optical regeneration gain mechanism in Example 2 of the present invention.

[0037] Figure 10 This is a graph showing the external quantum efficiency of a visualized optical signal detection device based on an optical regeneration gain mechanism according to Example 2 of the present invention.

[0038] Figure 11 This is a dark current curve diagram of the visualized optical signal detection device based on the optical regeneration gain mechanism according to Example 2 of the present invention.

[0039] Figure 12 The image of the light source displayed on the surface of the device is a result of detecting a light source with the word "SCUT" using the visualized light signal detection device based on the light regeneration gain mechanism of Example 2 of the present invention.

[0040] Figure 13 (a) to (d) show the images of the light sources displayed on the device surface when the visualized light signal detection device based on the optical regeneration gain mechanism of Example 2 of the present invention is used to detect one, two, three, and four circular light sources.

[0041] Figure 14 for Figure 13 The relationship curve between the photocurrent and the number of circular light sources. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

[0043] The full names and molecular structures of some materials used in this invention are:

[0044] 1. TAPC: The full Chinese name is 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], and its structure is as follows:

[0045]

[0046] 2. C 60 :Chinese full name Fullerene C 60 , the structure is as follows:

[0047]

[0048] 3. C 70 :Chinese full name Fullerene C70 , the structure is as follows:

[0049]

[0050] 4. TCTA: The full name in Chinese is tris(4-carbazol-9-ylphenyl)amine, and its structure is as follows:

[0051]

[0052] 5. mCBP: Chinese full name 3,3'-di(N-carbazolyl)-1,1'-biphenyl, the structure is as follows:

[0053]

[0054] 5. PO-T2T: Chinese full name 2,4,6-tris[3-(diphenylphosphino)phenyl]-1,3,5-triazine, the structure is as follows:

[0055]

[0056] 6. FIrpic: The full name in Chinese is bis(4,6-difluorophenylpyridine-N,C2)picolinoyliridium, and its structure is as follows:

[0057]

[0058] 7. Liq: Chinese full name 8-hydroxyquinoline lithium, the structure is as follows:

[0059]

[0060] 8. HAT-CN: Chinese full name 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, the structure is as follows:

[0061]

[0062] 9. BCP: The full Chinese name is 2,9-dimethyl-4,7-diphenyl-1,10-o-phenanthroline, and the structure is as follows:

[0063]

[0064] 10. ZnO: Chinese full name is zinc oxide.

[0065] 11. ITO: The full Chinese name is indium tin oxide.

[0066] Example 1

[0067] The structural diagram of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment is shown in FIG. Figure 1As shown, from bottom to top, it includes a transparent substrate 1, an anode 2, a hole blocking layer 3, an electron transport layer 4, a photoactive layer 5, a hole transport layer 6, a light-emitting layer 7, an electron transport layer 8, a connecting layer 9, a hole transport layer 10, a light-emitting layer 11, an electron transport layer 12, an electron injection layer 13, and a metal cathode 14. Among them, the hole blocking layer 3, the electron transport layer 4, and the photoactive layer 5 constitute a light detection unit, the hole transport layer 6, the light-emitting layer 7, and the electron transport layer 8 constitute a first light-emitting unit, and the hole transport layer 10, the light-emitting layer 11, and the electron transport layer 12 constitute a second light-emitting unit.

[0068] In this embodiment, the transparent substrate 1 is glass; the anode 2 is indium tin oxide (ITO); the hole blocking layer 3 is BCP with a thickness of 16 nm; the electron transport layer 4 is made of C 60 , with a thickness of 30nm; the photoactive layer 5 is a blended film of electron donor material and electron acceptor material, with a thickness of 200nm. 60 , the mass concentration of the electron donor material in the photoactive layer 5 is 30wt%; the hole transport layer 6 is a three-layer structure consisting of a TAPC layer, a TCTA layer and a mCBP layer; the thickness of the TAPC layer is 40nm; the thickness of the TCTA layer and the mCBP layer are both 5nm; the light-emitting layer 7 is composed of an exciplex as the main body and a blue phosphorescent material FIrpic as the guest, and the thickness is 30nm; the exciplex is formed by blending the electron donor material mCBP and the electron acceptor material PO-T2T; the mass concentration ratio between the electron donor material, the electron acceptor material and the blue phosphorescent material in the light-emitting layer 7 is 1:1:0.15; the material of the electron transport layer 8 is PO-T2T, and its thickness is 55nm; the connecting layer 9 includes a Liq layer, an A layer 1 and a HAT-CN layer, wherein the thickness of the Liq layer is 1.5nm, the thickness of the Al layer is 1nm, the thickness of the HAT-CN layer is 10 nm; the hole transport layer 10 is a three-layer structure consisting of a TAPC layer, a TCTA layer and a mCBP layer, wherein the thickness of the TAPC layer is 40 nm, and the thickness of the TCTA layer and the mCBP layer are both 5 nm; the light-emitting layer 11 is composed of an exciplex as the main body and a blue phosphorescent material FIrpic as the guest, with a thickness of 30 nm; the exciplex is formed by blending an electron donor material mCBP and an electron acceptor material PO-T2T; the mass concentration ratio between the electron donor material, the electron acceptor material and the blue phosphorescent material in the light-emitting layer 11 is 1:1:0.15; the material of the electron transport layer 12 is PO-T2T, and its thickness is 55 nm; the material of the electron injection layer 13 is Liq, and its thickness is 1.5 nm; the cathode 14 is metallic aluminum, and its thickness is 100 nm.

[0069] The specific preparation method of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment is as follows:

[0070] The glass substrate with ITO anode was ultrasonically cleaned in a detergent solution for 90 minutes, then rinsed with deionized water and dried with nitrogen, and then baked in a vacuum oven at 120°C for 30 minutes. The dried ITO glass was treated with oxygen plasma for 4 minutes to further remove impurities remaining on the ITO surface, and then transferred to the vacuum evaporation system. When the vacuum degree in the vacuum evaporation system reached ~10 -5 Pa, a hole blocking layer 3, an electron transport layer 4, a photoactive layer 5, a hole transport layer 6, a light-emitting layer 7, an electron transport layer 8, a connecting layer 9, a hole transport layer 10, a light-emitting layer 11, an electron transport layer 12, an electron injection layer 13 and a metal cathode 14 are sequentially deposited on the anode 2. The device consists of two overlapping electrodes with an effective area of ​​20 mm 2 The final structure is Glass / ITO / BCP (16nm) / C 60 (30nm) / TAPC:C 60 (30%,200nm) / TAPC(40nm) / TCTA(5nm) / mCBP(5nm) / mCBP:PO-T2T:FIrpic(1:1:0.15,30nm) / PO-T2T(55nm) / Liq(1.5nm) / Al(1nm) / HATCN(10nm) / TAPC(40nm) / TCTA(5nm) / mCBP(5nm) / mCBP:PO-T2T:FIrpic(1:1:0.15,30nm) / PO-T2T(55nm) / Liq(1.5nm) / Al(100nm).

[0071] Figure 2This is a schematic diagram of the operating mechanism of a visual optical signal detection device based on the photoregeneration gain mechanism according to an embodiment of the present invention. The specific process is as follows: Under illumination and applied bias, the photoactive layer absorbs incident photons to generate excitons, which then separate into incident photogenerated electrons and incident photogenerated holes. The incident photogenerated electrons drift to the anode and are collected to form a photocurrent, which is referred to as the incident photocurrent. Meanwhile, the incident photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate new photons, which are referred to as self-generated photons. Like incident photons, self-generated photons are absorbed by the photoactive layer, generating additional photocurrent, known as the self-generated photocurrent. The self-generated holes also drift to the light-emitting layer and recombine with electrons injected from the cathode to generate new self-generated photons, a process known as photoregeneration. Clearly, the photoregeneration process occurs cyclically. Under continuous illumination, the photoactive layer continuously absorbs incident photons, driving the light-emitting layer to generate more self-generated photons, which in turn increases the number of self-generated photons. However, because the photoelectric conversion efficiency within the device and the absorption rate of self-generated photons by the active layer cannot reach 100%, the rate of increase of self-generated photons decreases over time, which also means that the number of self-generated photons has a maximum value. When the number of self-generated photons reaches the maximum value, the device reaches a steady state, and the total photocurrent is the sum of the incident photocurrent generated by the active layer absorbing the incident photons and the self-generated photocurrent generated by the self-generated photons, ultimately showing a large photocurrent gain.

[0072] At the same time, under illumination and applied bias, the photoactive layer cannot fully absorb the self-generated photons produced by the light-emitting unit, so some of the self-generated photons are emitted from the anode. Furthermore, in a dark environment, the device's ultra-low dark current is insufficient to drive the light-emitting unit to emit light. When a light source with a certain shape shines on the device, the illuminated areas can drive the light-emitting unit to produce self-generated photons, while the unilluminated areas do not produce photons. This creates an image of the light source on the device surface, allowing direct observation of the light source's shape.

[0073] Figure 3 This is the normalized absorption spectrum of the photoactive layer in the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment. As can be seen from the figure, the absorption spectrum of TAPC is in the range of 300-400 nm; C 60 It has good absorption in the visible light range, and the main absorption spectrum range is 300-550 nm; TAPC:C 60 The main absorption spectrum of the blend film is in the range of 300-500nm.

[0074] Figure 4This figure shows the electroluminescence spectrum of the light-emitting layer in the device for visualizing optical signal detection based on the optical regeneration gain mechanism of this embodiment. As can be seen from the figure, the luminescence spectrum of the mCBP: PO-T2T: FIrpic blend film ranges from 450-600 nm, with a peak at 490 nm, indicating that the self-generated photons generated by the light-emitting layer are absorbed by the photoactive layer.

[0075] Figure 5 This is a graph showing the external quantum efficiency of the visualized optical signal detection device based on the optical regeneration gain mechanism of this embodiment. As can be seen from the graph, the device's external quantum efficiency continues to improve with increasing forward bias voltage, reaching a maximum external quantum efficiency of 130% at a wavelength of 440 nm at a bias voltage of 13 V.

[0076] Figure 6 This is a dark current curve of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment. Under a bias voltage of 13 V, the device still maintains a 5×10 -8 Acm -2 The above test results show that the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment has high sensitivity when used to detect weak signals.

[0077] Figure 7 (a) and (b) show the normalized transient photocurrent response (Jt curve) and electroluminescence (EL) characteristic curve of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment under the illumination of an LED with a pulse frequency of 100 Hz and a peak wavelength of 535 nm. It can be seen that the growth trajectory of the photocurrent can be clearly divided into two stages: in the first stage, the transient photocurrent of the device rises rapidly (e.g., Figure 7 (shown within the dashed circle in (a)). This portion of the photocurrent is generated by the active layer absorbing incident photons. Meanwhile, the EL intensity is almost zero, confirming that no self-generated photons have yet been generated in the light-emitting layer. In the second phase, the EL intensity begins to rise, also indicating the generation of self-generated photons. Simultaneously, the transient photocurrent begins to rise, and its rate of increase is almost consistent with that of the EL intensity. This confirms that the active layer absorbs self-generated photons, generating additional photocurrent and contributing to photocurrent gain in the device.

[0078] Figure 8 for Figure 7 The direct relationship between transient photocurrent and electroluminescence intensity is shown in the characteristic graph. It is clearly visible that when the electroluminescence intensity approaches zero, the transient photocurrent rises rapidly. With the onset of the photoregeneration process, the electroluminescence intensity begins to increase. More importantly, the mutual conversion relationship between transient photocurrent and self-generated photons, as shown by a linear fit of the latter half of the curve, confirms the existence of the photoregeneration process.

[0079] The visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment can be assembled with a DC power supply and a current measuring unit to form a visual optical signal detection device based on the optical regeneration gain mechanism. The current measuring unit is used to measure and display the photocurrent at the transparent anode. During detection, the magnitude of the photocurrent can reflect the distance between the device and the light source to a certain extent, which is conducive to quickly finding the light source; the DC power supply is connected to the anode and the anode of the visual optical signal detection device based on the optical regeneration gain mechanism to provide an operating voltage.

[0080] In this embodiment, under the continuous illumination of the light source to be measured, light regeneration occurs cyclically in the device, and the self-generated photocurrent continues to increase, so that the photocurrent at the anode is gained. At the same time, the dark current is low and the detection sensitivity is high, which is conducive to the detection of weak light signals. There is no need for an additional display unit. The image of the light source is directly imaged on the visual light signal detection device based on the light regeneration gain mechanism, which is conducive to the simplification of the detection equipment structure.

[0081] Example 2

[0082] The structure of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment is the same as that of embodiment 1. Figure 1 , which includes, in sequence, a transparent substrate 1, an anode 2, a hole blocking layer 3, an electron transport layer 4, a photoactive layer 5, a hole transport layer 6, a light-emitting layer 7, an electron transport layer 8, a connecting layer 9, a hole transport layer 10, a light-emitting layer 11, an electron transport layer 12, an electron injection layer 13 and a metal cathode 14; wherein, the hole blocking layer 3, the electron transport layer 4 and the photoactive layer 5 constitute a light detection unit, the hole transport layer 6, the light-emitting layer 7 and the electron transport layer 8 constitute a first light-emitting unit, and the hole transport layer 10, the light-emitting layer 11 and the electron transport layer 12 constitute a second light-emitting unit.

[0083] In this embodiment, the transparent substrate 1 is glass; the anode 2 is indium tin oxide (ITO); the hole blocking layer 3 is ZnO, and its thickness is 35nm; the material of the electron transport layer 4 is C 60 , with a thickness of 30 nm; the photoactive layer 5 is a blended film of electron donor material and electron acceptor material, with a thickness of 200 nm. Wherein, the electron donor material is TAPC, and the electron acceptor material is C 70, the mass concentration of the electron donor material in the photoactive layer 5 is 15wt%; the hole transport layer 6 is a three-layer structure consisting of a TAPC layer, a TCTA layer and a mCBP layer; the thickness of the TAPC layer is 10nm; the thickness of the TCTA layer and the mCBP layer are both 5nm; the light-emitting layer 7 is composed of an exciplex as the main body and a blue phosphorescent material FIrpic as the guest, and the thickness is 30nm; the exciplex is formed by blending the electron donor material mCBP and the electron acceptor material PO-T2T; the mass concentration ratio between the electron donor material, the electron acceptor material and the blue phosphorescent material in the light-emitting layer 7 is 1:1:0.15; the material of the electron transport layer 8 is PO-T2T, and its thickness is 35nm; the connecting layer 9 includes a Liq layer, an Al layer and a HAT-CN layer, wherein the thickness of the Liq layer is 1.5nm, the thickness of the Al layer is 1nm, and the thickness of the HAT-CN layer is 10nm. nm; the hole transport layer 10 is a three-layer structure consisting of a TAPC layer, a TCTA layer and a mCBP layer, and the thickness of the TAPC layer, the TCTA layer and the mCBP layer are all 5 nm; the light-emitting layer 11 is composed of an exciplex as the main body and a blue phosphorescent material FIrpic as the guest, and has a thickness of 30 nm; the exciplex is formed by blending an electron donor material mCBP and an electron acceptor material PO-T2T; the mass concentration ratio between the electron donor material, the electron acceptor material and the blue phosphorescent material in the light-emitting layer 11 is 1:1:0.15; the material of the electron transport layer 12 is PO-T2T, and its thickness is 35 nm; the material of the electron injection layer 13 is Liq, and its thickness is 1.5 nm; the cathode 14 is metallic aluminum, and its thickness is 100 nm.

[0084] The specific preparation method of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment is as follows:

[0085] The glass substrate 1 with the anode 2 was ultrasonically cleaned in a cleaning solution for 90 minutes, then rinsed with deionized water and dried with nitrogen, and then baked in a vacuum oven at 120°C for 30 minutes. The dried ITO glass was treated with oxygen plasma for 4 minutes to further remove impurities remaining on the ITO surface, and then transferred to the vacuum evaporation system. When the vacuum degree in the vacuum evaporation system reached ~10 -5 Pa, a hole blocking layer 3, an electron transport layer 4, a photoactive layer 5, a hole transport layer 6, a light-emitting layer 7, an electron transport layer 8, a connecting layer 9, a hole transport layer 10, a light-emitting layer 11, an electron transport layer 12, an electron injection layer 13 and a metal cathode 14 are sequentially deposited on the ITO anode 2. The device consists of two overlapping electrodes, and its effective area is 20 mm 2 The final structure is Glass / ITO / ZnO(35 nm) / C 60(30 nm) / TAPC:C 70 (15%,200 nm) / TAPC(10 nm) / TCTA(5 nm) / mCBP(5 nm) / mCBP:PO-T2T:FIrpic(1:1:0.15,30nm) / PO-T2T(35nm) / Liq(1.5nm) / Al(1nm) / H AT-CN(10nm) / TAPC(5nm) / TCTA(5nm) / mCBP(5nm) / mCBP:PO-T2T:FIrpic(1:1:0.15,30 nm) / PO-T2T(35 nm) / Liq(1.5 nm) / Al(100 nm).

[0086] The working principle of the visualized optical signal detection device based on the optical regeneration gain mechanism of this embodiment is the same as that of the first embodiment.

[0087] Figure 9 This is the normalized absorption spectrum of the photoactive layer of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment. As can be seen from the figure, the absorption spectrum range of TAPC is 300-400 nm, C 70 It has good absorption in the visible light range, with the main absorption spectrum range being 300-700 nm. 70 The main absorption spectrum of the blended film is in the range of 300-700nm, and its absorption efficiency for visible light is much higher than that of C 60 .

[0088] Figure 10 This is a graph showing the external quantum efficiency of the visualized optical signal detection device based on the optical regenerative gain mechanism of this embodiment. As can be seen from the graph, the device's external quantum efficiency significantly increases with increasing forward bias. At a bias of 7.5 V, the external quantum efficiency exceeds 100% over the wavelength range of 300-800 nm, reaching a maximum of 2483% at a wavelength of 400 nm.

[0089] Figure 11 This is a dark current curve of the visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment. As can be seen from the figure, under the bias voltage of 8 V, the device still has a 9×10 -8 Acm -2 Ultra-low dark current of orders of magnitude.

[0090] Figure 12The visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment is used to detect a light source with the word "SCUT". The image of the light source displayed on the surface of the device is as follows: Figure 13 As shown in (a) to (d). Figure 14 The graph shows the relationship between photocurrent and the number of circular light sources. As can be seen from the figure, under different numbers of light sources, the number and shape of light spots can be clearly seen on the device. The proportional relationship between the number of light spots and photocurrent reflects the uniformity of the device.

[0091] The visual optical signal detection device based on the optical regeneration gain mechanism of this embodiment can be assembled with a DC power supply and a current measuring unit to form a visual optical signal detection device based on the optical regeneration gain mechanism. The current measuring unit is used to measure and display the photocurrent at the transparent anode. During detection, the magnitude of the photocurrent can reflect the distance between the device and the light source to a certain extent, which is conducive to quickly finding the light source; the DC power supply is connected to the anode and the anode of the visual optical signal detection device based on the optical regeneration gain mechanism to provide an operating voltage.

[0092] In this embodiment, under the continuous illumination of the light source to be measured, light regeneration occurs cyclically in the device, and the self-generated photocurrent continues to increase, so that the photocurrent at the anode is gained. At the same time, the dark current is low and the detection sensitivity is high, which is conducive to the detection of weak light signals. There is no need for an additional display unit. The image of the light source is directly imaged on the visual light signal detection device based on the light regeneration gain mechanism, which is conducive to the simplification of the detection equipment structure.

[0093] In the above embodiment, the light emitting unit may also be designed to be one, three or other numbers according to actual conditions.

[0094] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A visual optical signal detection device based on an optical regeneration gain mechanism, characterized in that: The method comprises, in sequence, a transparent substrate, a transparent anode, a light detection unit, at least one light emitting unit, an electron injection layer, and a cathode; The light detection unit includes a hole blocking layer, a first electron transport layer, and a photoactive layer in sequence; the photoactive layer is formed by mixing TAPC and fullerene; the fullerene is C 60 or C 70 ; The mass concentration of TAPC is 15wt%~30wt%; the thickness of the photoactive layer is 200 nm; The light-emitting unit includes a hole transport layer, a light-emitting layer, and a second electron transport layer in sequence; the light-emitting layer uses an exciplex as a host and a phosphorescent material as a guest; When the visual optical signal detection device is working, under the illumination of the light source to be measured and the action of forward bias, the photoactive layer absorbs incident photons to generate photogenerated electrons and photogenerated holes; the photogenerated electrons drift to the anode to form an incident photocurrent, and the photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate self-generated photons; a part of the self-generated photons is emitted from the transparent substrate, forming an image of the light source on the visual optical signal detection device; the other part of the self-generated photons are absorbed by the photoactive layer and photoregeneration occurs: the photoactive layer absorbs self-generated photons to generate self-generated photogenerated electrons and self-generated photogenerated holes, the self-generated photogenerated electrons form a self-generated photocurrent at the anode, and the self-generated photogenerated holes drift to the light-emitting layer and recombine with electrons injected from the cathode to generate new self-generated photons; under the continuous illumination of the light source to be measured, the photoactive layer continuously absorbs incident photons to drive the light-emitting layer to generate self-generated photons, photoregeneration continues to occur, the number of self-generated photons continues to increase, and the self-generated photocurrent continues to increase, achieving photocurrent gain.

2. The visual optical signal detection device based on the optical regeneration gain mechanism according to claim 1, characterized in that: The exciplex is prepared by mixing mCBP and PO-T2T in a mass ratio of 1: (0.8-1.2).

3. The visual optical signal detection device based on the optical regeneration gain mechanism according to claim 1, characterized in that: The phosphorescent material is FIrpic; in the light-emitting layer, the mass concentration of the phosphorescent material is 6% to 30%.

4. The visual optical signal detection device based on the optical regeneration gain mechanism according to claim 1, characterized in that: The hole blocking layer is ZnO or BCP, and has a thickness of 10-50 nm.

5. The visual optical signal detection device based on the optical regeneration gain mechanism according to claim 1, characterized in that: The hole transport layer has a three-layer structure, including a TAPC layer, a TCTA layer and an mCBP layer.

6. The visual optical signal detection device based on the optical regeneration gain mechanism according to claim 5, characterized in that: The thickness of the TAPC layer is 5-60 nm, the thickness of the TCTA layer is 3-10 nm, and the thickness of the mCBP layer is 3-10 nm.

7. The visual optical signal detection device based on the optical regeneration gain mechanism according to any one of claims 1 to 6, characterized in that: When two or more light-emitting units are included, a connection layer is provided between the light-emitting units.

8. The visual optical signal detection device based on the optical regeneration gain mechanism according to claim 7, characterized in that: The connecting layer includes a Liq layer with a thickness of 1.5 to 2.5 nm, an Al layer with a thickness of 0.5 to 1.5 nm, and a HAT-CN layer with a thickness of 5 to 20 nm.

9. A visual optical signal detection device based on optical regeneration gain mechanism, characterized in that: The device comprises a DC power supply, a current measuring unit and a visual optical signal detection device based on the optical regeneration gain mechanism according to any one of claims 1 to 8; the current measuring unit is used to measure the photocurrent at the transparent anode.

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