Wide-spectrum photoelectric detector and preparation method thereof

Abstract

The invention provides a wide-spectrum photoelectric detector and a preparation method thereof, and relates to the technical field of photoelectric detectors, and the preparation method of the wide-spectrum photoelectric detector comprises the following steps: preparing an interdigital electrode on a conductive substrate; depositing perovskite quantum dots between the interdigital electrodes; and coating a protective layer on the interdigital electrode on which the perovskite quantum dots are deposited. Due to the fact that the interdigital electrode structure increases the contact area of the photosensitive material and the electrodes, the collection efficiency of photon-generated carriers can be effectively improved, and the sensitivity of the photoelectric detector is improved. As a photosensitive material, the perovskite quantum dots have a wide spectral absorption characteristic and high quantum efficiency, and can broaden the spectral response range of the detector. The coating of the protective layer can effectively isolate the influence of the external environment on the perovskite quantum dots, improves the stability of the device, and prolongs the service life. The preparation of the high-performance and stable wide-spectrum photoelectric detector is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric detectors, and in particular to a wide-spectrum photoelectric detector and a preparation method thereof. Background Art

[0002] Pulsed Laser Deposition (PLD) uses pulsed laser to sputter solid target materials in vacuum or special atmosphere, and the sputtered plasma plume is deposited on the substrate above the target to form a nanoparticle film. The nanofilm particles prepared by this technology have the advantages of good uniformity, stable composition, and high purity, and have been applied to the preparation of nanomaterials.

[0003] Photodetectors are key devices that convert optical signals into electrical signals and are widely used in many fields, such as image sensing, optical communications, environmental monitoring, and biomedicine. Wide-spectrum photodetectors, which are detectors that can respond to optical signals in a wide wavelength range, have received increasing attention in recent years due to their importance in multiple scenarios.

[0004] Photodetectors in specific wavelengths can meet the needs of different fields. For example, UV-vis photodetectors can meet the needs of astronomical detection or storage; visible light and near-infrared photodetectors are mainly used in consumer electronics and video recording. However, the existing technology lacks the technology to realize broadband photodetectors with wider spectrum and spectral characteristics.

[0005] Therefore, it is necessary to improve the existing wide-spectrum photodetector technology to overcome the above problems and realize a broadband photodetector with a light response of a wider spectrum and spectral characteristics. Summary of the invention

[0006] In order to overcome the problems existing in the related art, one of the objects of the present invention is to provide a method for preparing a wide-spectrum photodetector. The method for preparing a wide-spectrum photodetector solves the problems existing in the prior art through the synergistic effect of interdigitated electrodes, perovskite quantum dots and a protective layer, and realizes the preparation of a high-performance and high-stability wide-spectrum photodetector.

[0007] A method for preparing a wide spectrum photoelectric detector comprises the following steps:

[0008] preparing interdigitated electrodes on a conductive substrate;

[0009] depositing perovskite quantum dots between the interdigitated electrodes;

[0010] A protective layer is coated on the interdigital electrodes on which the perovskite quantum dots are deposited.

[0011] Since the interdigitated electrode structure increases the contact area between the photosensitive material and the electrode, the collection efficiency of photogenerated carriers can be effectively improved, thereby improving the sensitivity of the photodetector. As a photosensitive material, perovskite quantum dots have wide-spectrum absorption characteristics and high quantum efficiency, which can broaden the spectral response range of the detector. Coating a protective layer can effectively isolate the influence of the external environment on the perovskite quantum dots, improve the stability of the device, and extend the service life. A high-performance, stable wide-spectrum photodetector can be prepared.

[0012] Furthermore, the method for depositing perovskite quantum dots is a transmission pulse laser deposition method, in which the laser is a femtosecond laser;

[0013] The output power of the femtosecond laser is 10W to 30W;

[0014] The pulse width of the femtosecond laser is 350fs to 10ps;

[0015] The pulse repetition frequency of the femtosecond laser is in the range of 1 MHz to 50 MHz;

[0016] The pulse energy of the femtosecond laser is 10 μJ to 80 μJ.

[0017] Using transmission pulsed laser deposition, especially using femtosecond laser for perovskite quantum dot deposition, the deposition thickness and uniformity can be precisely controlled. The extremely short pulse width of the femtosecond laser can reduce the thermal effect and avoid damage to the perovskite quantum dots, thereby ensuring the excellent optoelectronic properties of the material. This limited laser parameter range can obtain high-quality perovskite quantum dot films, ultimately improving the performance of photodetectors.

[0018] Furthermore, the method of depositing perovskite quantum dots is magnetically focused transmission pulsed laser deposition.

[0019] Furthermore, in magnetic focusing transmission pulsed laser deposition, a uniform magnetic field with a magnetic field strength of 200 to 2000 Gs is used.

[0020] Preferably, in magnetic focusing transmission pulse laser deposition, the magnetic field strength is 1545 Gs.

[0021] The photoelectric sensor was obtained by deposition under an external magnetic field strength of 1545Gs. The photodetector prepared with this magnetic field strength had a detection rate (D*) of 3.5×10 10 Jones, and measured its responsivity (R) to be 56.6 mW / cm 2 .

[0022] Furthermore, the conductive substrate is a gold-plated glass sheet, the thickness of the gold-plated glass sheet is 0.3 mm to 1.0 mm, and the thickness of the gold-plated layer of the gold-plated glass sheet is 200 nm to 800 nm.

[0023] Using a gold-plated glass sheet as a conductive substrate and limiting its thickness and the thickness range of the gold-plated layer can ensure good conductivity and light transmittance of the substrate. The appropriate substrate thickness can provide sufficient mechanical strength, and the appropriate gold-plated layer thickness can take into account both conductivity and cost. This is beneficial to improving device performance and reducing manufacturing costs.

[0024] Furthermore, the length of the interdigital electrodes is 3 mm to 10 mm, the width is 9 mm to 30 mm, and the filling gap of the interdigital electrodes is 20 μm to 80 μm.

[0025] The length, width and filling gap of the interdigitated electrodes in this limited range can optimize the matching of the electrode structure with the perovskite quantum dot layer, thereby improving the collection efficiency of photogenerated carriers and the response speed of the device. The appropriate interdigital gap can balance light absorption and carrier collection, ultimately improving the performance of the photodetector.

[0026] Furthermore, the interdigital electrodes are prepared by laser etching, photolithography or sputtering deposition.

[0027] A variety of preparation methods for interdigitated electrodes are provided, such as laser etching, photolithography or sputtering deposition. The appropriate preparation process can be selected according to actual needs, thereby improving the flexibility of preparation and reducing the preparation cost.

[0028] Furthermore, the perovskite quantum dots are CsPbBr3 quantum dots, CsPbI3 quantum dots or CsPbCl3 quantum dots.

[0029] By clarifying the type of perovskite quantum dots, such as CsPbBr3, CsPbI3 or CsPbCl3, suitable materials can be selected for different spectral detection needs, thereby achieving high-sensitivity detection of specific bands.

[0030] Furthermore, the perovskite quantum dots are CsPbBr3 quantum dot powder.

[0031] Furthermore, the protective layer is polydimethylsiloxane, epoxy resin or ultraviolet curing resin, and is applied by spin coating, spray coating or dip coating.

[0032] A variety of protective layer materials and coating methods are provided for selection, and appropriate materials and processes can be selected according to actual needs, thereby improving the stability of the device and the flexibility of preparation.

[0033] Furthermore, the protective layer is polydimethylsiloxane, which is coated by spin coating, with a curing temperature of 50° C. to 80° C. and a curing time of 10 hours to 15 hours.

[0034] Furthermore, the thickness of the protective layer is 25 μm to 40 μm.

[0035] The protective layer thickness within this limited range can balance the protection effect and device performance. A protective layer that is too thick may affect the light response speed of the photodetector, while a protective layer that is too thin may not be able to effectively isolate the external environment.

[0036] The second object of the present invention is to provide a wide-spectrum photoelectric detector, which is prepared based on the above-mentioned method for preparing the wide-spectrum photoelectric detector, comprising:

[0037] Conductive substrate;

[0038] Interdigital electrodes are disposed on the conductive substrate;

[0039] a perovskite quantum dot layer, deposited between the interdigitated electrodes;

[0040] A protective layer covers the perovskite quantum dot layer and the interdigital electrodes.

[0041] Furthermore, the material of the protective layer is polydimethylsiloxane, and the perovskite quantum dot layer is CsPbBr3 quantum dots.

[0042] Using polydimethylsiloxane as a protective layer material can effectively isolate the impact of the external environment on perovskite quantum dots and improve the stability of the device. Using CsPbBr3 quantum dots as a photosensitive material can achieve high-sensitivity detection in the visible light band.

[0043] The beneficial effects of the present invention are:

[0044] The present invention provides a method for preparing a wide-spectrum photodetector, which includes three steps of preparing interdigitated electrodes on a conductive substrate, depositing perovskite quantum dots, and coating a protective layer. Since the interdigitated electrode structure increases the contact area between the photosensitive material and the electrode, the collection efficiency of photogenerated carriers can be effectively improved, thereby improving the sensitivity of the photodetector. Perovskite quantum dots, as photosensitive materials, have wide-spectrum absorption characteristics and high quantum efficiency, and can broaden the spectral response range of the detector. Coating a protective layer can effectively isolate the influence of the external environment on the perovskite quantum dots, improve the stability of the device, and extend the service life. A high-performance, stable wide-spectrum photodetector is prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1Schematic diagram of a magnetic focusing transmission pulsed laser deposition device provided in an embodiment of the present application.

[0046] Figure 2 This is a schematic diagram of the prepared photodetector provided in the examples of the present application.

[0047] Figure 3 The XRD patterns of the deposits obtained by bombarding CsPbBr3 quantum dot powder with a femtosecond laser at different magnetic field intensities provided in the examples of the present application.

[0048] Figure 4 This is the electrical signal response of a high-stability, wide-spectrum photodetector under a 265nm light source obtained by magnetic focusing transmission pulsed laser deposition technology under a magnetic field strength of 310Gs provided in an embodiment of the present application.

[0049] Figure 5 This is the electrical signal response of a high-stability wide-spectrum photodetector under a 450nm light source obtained by magnetic focusing transmission pulsed laser deposition technology under a magnetic field strength of 1237Gs provided in an embodiment of the present application.

[0050] Figure 6 This is the electrical signal response of a high-stability wide-spectrum photodetector under an 800nm ​​light source obtained by magnetic focusing transmission pulsed laser deposition technology under a magnetic field strength of 771Gs provided in an embodiment of the present application.

[0051] Figure 7 The stability of the high-stability wide-spectrum photodetector obtained by the magnetic focusing transmission pulsed laser deposition technology under a magnetic field strength of 310 Gs provided in the embodiments of the present application;

[0052] Figure 8 This is a flow chart of a method for preparing a wide-spectrum photoelectric detector provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0054] Example

[0055] like Figures 1 to 8 As shown, this embodiment provides a method for preparing a wide-spectrum photoelectric detector, and the method for preparing the wide-spectrum photoelectric detector includes the following steps:

[0056] Step 100, preparing interdigital electrodes on a conductive substrate;

[0057] Step 200, depositing perovskite quantum dots between the interdigitated electrodes;

[0058] Step 300: coating a protective layer on the interdigital electrodes on which the perovskite quantum dots are deposited.

[0059] In step 200, the method for depositing perovskite quantum dots is a transmission pulsed laser deposition method, in which the laser is a femtosecond laser;

[0060] The output power of the femtosecond laser is 10W to 30W;

[0061] The pulse width of the femtosecond laser is 350fs to 10ps;

[0062] The pulse repetition frequency of the femtosecond laser is in the range of 1 MHz to 50 MHz;

[0063] The pulse energy of the femtosecond laser is 10 μJ to 80 μJ.

[0064] In step 100, the conductive substrate is a gold-plated glass sheet, the thickness of the gold-plated glass sheet is 0.3 mm to 1.0 mm, and the thickness of the gold-plated layer of the gold-plated glass sheet is 200 nm to 800 nm.

[0065] In step 100 , the length of the interdigital electrodes is 3 mm to 10 mm, the width is 9 mm to 30 mm, and the filling gap of the interdigital electrodes is 20 μm to 80 μm.

[0066] In step 100, the interdigital electrodes are prepared by laser etching, photolithography or sputtering deposition.

[0067] In step 200, the perovskite quantum dots are CsPbBr3 quantum dots, CsPbI3 quantum dots or CsPbCl3 quantum dots.

[0068] In step 300, the protective layer is polydimethylsiloxane, epoxy resin or ultraviolet curing resin, and is applied by spin coating, spray coating or dip coating.

[0069] In step 300 , the protective layer has a thickness of 25 μm to 40 μm.

[0070] More specifically, in this embodiment, a wide spectrum photodetector based on CsPbBr3 quantum dots is prepared by this method, using Figure 1 The magnetic focusing transmission pulse laser deposition device shown is used for preparation, and the magnetic focusing transmission pulse laser deposition device includes a energized solenoid, a moving platform and a femtosecond laser.

[0071] The preparation process specifically includes:

[0072] The interdigital electrodes were ablated on a gold-coated glass sheet. The femtosecond laser output power was set to 18 W, the pulse width was 532 fs, the pulse repetition frequency was 32 MHz, and the pulse energy was 35 μJ.

[0073] The gold-coated glass sheet has a thickness of 0.8 mm and a gold-coated layer thickness of 350 μm. It is placed vertically under the femtosecond laser beam with the gold-coated surface facing downward to facilitate the subsequent sputtering deposition of the target material.

[0074] The electric platform was moved to find the best focus of the laser and the interdigitated electrodes were etched. The length of the interdigitated electrodes was 5 mm and the width was 7 mm. The gap between the interdigitated electrodes was 30 μm, and a gold electrode was obtained.

[0075] CsPbBr3 quantum dot electrodes were deposited on a conductive substrate.

[0076] A pressed CsPbBr3 quantum dot powder target is placed under the conductive substrate, the distance between the target and the substrate is set to 0.5mm, and the entire device is placed in an energized solenoid (uniform magnetic field). The electric platform is moved, and the laser sinks 0.5mm and focuses on the surface of the target for magnetic focusing transmission pulse laser deposition. The femtosecond laser output power is 13W, the pulse width is 450fs, the pulse repetition frequency is 30MHz, the pulse energy is 15μJ, the magnetic field strength is 771Gs, and the photoelectric sensor is obtained after the deposition.

[0077] Sealing layer of photoelectric detection device.

[0078] The obtained photoelectric sensor was placed on a spin coater, 1 ml of PDMS was dropped on the surface of the photoelectric sensor, and the device was run at a low speed of 500 rpm for 5 s and a high speed of 3000 rpm for 20 s to obtain a protective layer with a thickness of 500 μm. The device was further transferred to a 60°C oven and heated for 13 h.

[0079] A wide spectrum detectable photoelectric sensor can be obtained by the above method.

[0080] Figure 2 This is the phase analysis of CsPbBr3 deposited on the substrate by changing the magnetic field strength in this embodiment. It can be observed from the figure that the magnetic field strength does not affect the crystal phase of CsPbBr3, but as the magnetic field strength increases, the crystallinity becomes higher and higher. Good crystallinity lays the foundation for its preparation of photoelectric sensors.

[0081] Figure 3This is the photocurrent response spectrum of the photoelectric sensor obtained by magnetic focusing transmission pulsed laser deposition under an external magnetic field strength of 310Gs in this embodiment. In the absence of bias, the generation of photocurrent can be clearly seen under the stimulation of 365nm light sources of different powers.

[0082] Figure 4 This is the photocurrent response spectrum of the photoelectric sensor obtained by magnetic focusing transmission pulsed laser deposition under an external magnetic field strength of 1237Gs in this embodiment. Without applying a bias voltage, the generation of photocurrent can be clearly seen under the stimulation of 450nm light sources of different powers, indicating that the photoelectric device also has a good response to visible light.

[0083] Figure 5 This is the photocurrent response spectrum of the photoelectric sensor obtained by magnetic focusing transmission pulsed laser deposition under an external magnetic field strength of 710Gs in this embodiment. Without applying a bias voltage, the generation of photocurrent can be clearly seen under the stimulation of 800nm ​​light sources of different powers, which shows the wide spectrum detectability of the photoelectric device and realizes effective detection from ultraviolet-visible light to near infrared.

[0084] Figure 6 The photoelectric sensor obtained by magnetic focusing transmission pulsed laser deposition under an external magnetic field strength of 310Gs in this embodiment shows the photoelectric signal response under the stimulation of an external light source of 0V@365nm for about one month. Under the stimulation of a suitable low-power light source signal, the photocurrent signal is even stronger than the initial signal. After one month, the photocurrent signal under the stimulation of a high-power light source signal can still maintain 63% of the original electrical signal, indicating that the PDMS film provides good protection for the photoelectric sensor.

[0085] In this embodiment, a photoelectric sensor is obtained by magnetic focusing transmission pulsed laser deposition under an external magnetic field strength of 1545 Gs. The photoelectric detector prepared using this magnetic field strength has a detection rate (D*) of 3.5×10 10 Jones, and measured its responsivity (R) to be 56.6 mW / cm 2 .

[0086] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a restriction. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in the subsequent accompanying drawings.

[0087] In addition, it should be noted that the use of terms such as "first" and "second" to limit is only for the convenience of distinction. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a wide spectrum photoelectric detector, characterized in that: The following steps are involved: preparing interdigitated electrodes on a conductive substrate; depositing perovskite quantum dots between the interdigitated electrodes; A protective layer is coated on the interdigital electrodes on which the perovskite quantum dots are deposited.

2. The method for preparing a wide spectrum photoelectric detector according to claim 1, characterized in that: The method for depositing perovskite quantum dots is a transmission pulse laser deposition method, in which the laser is a femtosecond laser; The output power of the femtosecond laser is 10W to 30W; The pulse width of the femtosecond laser is 350fs to 10ps; The pulse repetition frequency of the femtosecond laser is in the range of 1 MHz to 50 MHz; The pulse energy of the femtosecond laser is 10 μJ to 80 μJ.

3. The method for preparing a wide spectrum photoelectric detector according to claim 1, characterized in that: The conductive substrate is a gold-plated glass sheet, the thickness of the gold-plated glass sheet is 0.3 mm to 1.0 mm, and the thickness of the gold-plated layer of the gold-plated glass sheet is 200 nm to 800 nm.

4. The method for preparing a wide spectrum photoelectric detector according to claim 1, characterized in that: The length of the interdigital electrodes is 3 mm to 10 mm, the width is 9 mm to 30 mm, and the filling gap of the interdigital electrodes is 20 μm to 80 μm.

5. The method for preparing a wide spectrum photoelectric detector according to claim 1, characterized in that: The preparation method of the interdigital electrodes is laser etching, photolithography or sputtering deposition.

6. The method for preparing a wide spectrum photoelectric detector according to claim 1, characterized in that: The perovskite quantum dots are CsPbBr3 quantum dots, CsPbI3 quantum dots or CsPbCl3 quantum dots.

7. The method for preparing a wide spectrum photoelectric detector according to claim 1, characterized in that: The protective layer is polydimethylsiloxane, epoxy resin or ultraviolet curing resin, and is coated by spin coating, spray coating or dip coating.

8. The method for preparing a wide spectrum photoelectric detector according to claim 7, characterized in that: The protective layer has a thickness of 25 μm to 40 μm.

9. A wide spectrum photoelectric detector, characterized in that: The method for preparing a wide-spectrum photoelectric detector according to any one of claims 1 to 8 comprises: Conductive substrate; Interdigital electrodes are disposed on the conductive substrate; a perovskite quantum dot layer, deposited between the interdigitated electrodes; A protective layer covers the perovskite quantum dot layer and the interdigital electrodes.

10. The photodetector according to claim 9, characterized in that: The material of the protective layer is polydimethylsiloxane, and the perovskite quantum dot layer is CsPbBr3 quantum dots.

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