Micro flexible multi-spectrum detector and preparation method thereof

Abstract

The application discloses a kind of micro flexible multispectral detector and preparation method thereof.The method first uses spin coating method to be on the PET flexible substrate of spin coating hole transport layer PEDOT:PSS with organic donor precursor solution, donor layer film is prepared, then different patterns mask is covered in upper layer in sequence, 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F acceptor material solution are respectively spin coated in different areas, acceptor layer array is prepared, finally, mask is used in sequence Vacuum evaporation LiF barrier layer and silver electrode, and micro flexible multispectral detector is prepared.The organic narrow-band multispectral flexible detection array constructed by the application does not need optical element light filtering, and narrow-band multispectral reconstruction with a response half-width of at least 50nm can be realized through software algorithm, and the spectral resolution can reach 50nm, providing a way for flexible wearable narrow-band multispectral detector.

Description

Technical Field

[0001] This invention belongs to the field of organic multispectral detection and relates to a miniature flexible multispectral detector and its fabrication method. Background Technology

[0002] Different substances possess unique spectral signals. In recent years, multispectral detection technology based on spectral recognition has been widely applied in intelligent fields such as autonomous driving, biological monitoring, and encrypted communication. However, achieving the recognition of optical signals often relies on bulky optical spectrometers, interferometric systems, or filter components. These hardware components inevitably increase the size of the detection system, making it difficult to further integrate them into intelligent devices such as mobile devices and wearable devices. Currently, although microelectromechanical processing techniques have enabled further miniaturization of dispersive and filtering devices, this has also inadvertently increased the complexity of the structure and design.

[0003] Organic materials, due to their inherent flexibility, play a crucial role in wearable devices, medical detection, and other fields. Single-wavelength narrowband detectors have been fabricated through methods such as internal quantum efficiency modulation (Nat. Commun., 2015, 6, 6343) or intermolecular charge transfer absorption (Nat. Commun., 2017, 8, 15421). However, these methods rely on excessively thick organic layers, leading to attenuation of the response and requiring extremely high operating voltages.

[0004] Narrowband multispectral flexible detector arrays based on organic materials possess both self-spacing and detection functions, eliminating the need for additional optical components. Furthermore, their inherent flexibility and excellent stability make them highly promising for wearable applications. Summary of the Invention

[0005] The purpose of this invention is to provide a miniature flexible multispectral detector and its fabrication method.

[0006] The technical solution for achieving the objective of this invention is as follows:

[0007] The fabrication method of a miniature flexible multispectral detector includes the following steps:

[0008] (1) In a N2 atmosphere, prepare a PTB7-Th organic donor precursor solution with a concentration of 15-20 mg / mL;

[0009] (2) On an ITO / PET flexible substrate coated with a hole transport layer, an organic donor precursor solution is spin-coated at a speed of 1000-1200 rpm and annealed at 100°C for 20-30 min to prepare a donor layer film.

[0010] (3) Masks with different patterns were sequentially covered on the donor layer film. At a speed of 1900-2100 rpm, 8-12 mg / mL of tert-butylamine (6TBA), IT-4Cl, 4TIC-4F and 6TIC-4F receptor material solutions were spin-coated in different areas. The solutions were then annealed at 100℃ for 10-15 min to prepare the receptor layer array.

[0011] (4) A miniature flexible multispectral detector was fabricated by vacuum evaporating a LiF barrier layer and a silver electrode on the acceptor layer array using a mask.

[0012] Preferably, in step (1), the thickness of the donor layer is 380 nm.

[0013] Preferably, in step (1), PTB7-Th is dissolved in chlorobenzene and stirred at 50-70°C for more than 2 hours to prepare a PTB7-Th organic donor precursor solution.

[0014] Preferably, in step (2), the hole transport layer is PEDOT:PSS, the spin coating speed during the hole transport layer preparation process is 4000 rpm, and the annealing temperature is 140℃ for 15 min.

[0015] Preferably, in step (3), the thickness of the receptor layer is 160 nm.

[0016] Preferably, in step (3), the rotational speed is 2000 rpm.

[0017] Preferably, in step (3), receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F are dissolved in chlorobenzene and stirred at room temperature for more than 2 hours to prepare receptor material solutions.

[0018] Preferably, in step (4), the thickness of the LiF barrier layer is 1 nm and the thickness of the silver electrode is 100 nm.

[0019] The present invention also provides a spectral recognition algorithm based on the above-mentioned miniature flexible multispectral detector, comprising the following steps:

[0020] (1) Using spectroscopic equipment, the spectral calibration of the miniature flexible multispectral detector array unit is performed, and the spectral response of each detector unit is denoted as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed;

[0021] (2) Measure the response current generated by the detector array to the spectrum to be reconstructed, denoted as I. i I i It is a one-dimensional column vector;

[0022] (3) Reconstruct using the following formula:

[0023]

[0024] Where F(λ) represents the spectrum to be reconstructed, and is a one-dimensional column vector, F(λ) can be obtained by performing the inverse operation of the integral, i.e., F = R -1 I.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) The detector array of the miniature flexible multispectral detector of the present invention has both spectral dispersion and photosensitive functions, and can generate a current response to light of different wavelengths. Combined with the algorithm, the overall structure and volume are greatly simplified.

[0027] (2) Exciton dissociation modulation enables narrow-band response to be achieved simply by adjusting the donor layer thickness, simplifying the subsequent spectral processing procedure.

[0028] (3) Based on multispectral detection, this invention achieves further device flexibility by selecting organic materials, providing possibilities for wearable devices. Attached Figure Description

[0029] Figure 1 The image shows the AFM diagram of the donor layer PTB7-Th and its upper acceptor layer IT-4Cl in Example 1.

[0030] Figure 2 This is an AFM cross-sectional view of the donor layer PTB7-Th and its upper acceptor layer IT-4Cl in Example 1.

[0031] Figure 3 The EQE curves are for the IT-4Cl unit in the detector array prepared in Example 1.

[0032] Figure 4 The transmittance curve is shown for the donor layer PTB7-Th in Example 2.

[0033] Figure 5 This is a surface scan PL image of the donor layer PTB7-Th and its upper receptor layer IT-4Cl in Example 2.

[0034] Figure 6 The EQE curves are for the IT-4Cl unit in the detector array prepared in Example 2.

[0035] Figure 7 The EQE curves of the IT-4Cl unit in the detector array prepared in Example 3 under different voltages are shown.

[0036] Figure 8 The image shows the bright / dark IV curves of the IT-4Cl unit in the detector array prepared in Example 3.

[0037] Figure 9 The image shows the EQE curve of the detector array prepared in Example 3.

[0038] Figure 10 The EQE curves are for the IT-4Cl units in the detector array prepared in Comparative Example 1.

[0039] Figure 11 The EQE curves of the IT-4Cl unit in the detector array prepared in Comparative Example 2 are shown.

[0040] Figure 12 The EQE curves of the IT-4Cl unit in the detector array prepared in Comparative Example 3 are shown. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0042] Example 1

[0043] (1) In a N2 atmosphere, a PTB7-Th organic donor precursor solution with a concentration of 20 mg / mL was prepared and stirred at 60 °C for 2 h.

[0044] (2) A hole transport layer PEDOT:PSS was spin-coated on an ITO / PET flexible substrate at 4000 rpm and annealed at 140℃ for 15 min.

[0045] (3) On the cavity layer, an organic donor precursor solution was spin-coated at 1200 rpm to prepare a donor layer film, which was then annealed at 100°C for 25 min.

[0046] (4) On the prepared donor layer film, masks with different patterns are sequentially covered, and 10 mg / mL receptor material solutions 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F are spin-coated in different areas at 2000 rpm. The samples are then annealed at 100℃ for 10-15 min to prepare the receptor layer array.

[0047] (5) A 1 nm thick LiF barrier layer and a 100 nm thick silver electrode were sequentially vacuum-deposited using a mask.

[0048] (6) Using a spectroscopic device, the prepared detector array units were spectrally calibrated, and the spectral response of each detector unit was labeled as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed.

[0049] (7) Measure the response current generated by the detector array of the light to be reconstructed, denoted as I. i I i It is a one-dimensional column vector.

[0050] (8) Reconstruct using the following formula:

[0051]

[0052] Here, F(λ) represents the spectrum to be reconstructed and is a one-dimensional column vector. F(λ) can be obtained by performing the inverse operation on the integral, i.e., F = R. -1 I.

[0053] The AFM image of the donor layer PTB7-Th and the acceptor layer IT-4Cl prepared in Example 1 is shown below. Figure 1 As shown, it has a smooth surface and low roughness. The corresponding cross-sectional view is as follows. Figure 2 As shown, the thicknesses of the donor layer PTB7-Th and the acceptor layer IT-4Cl are 380 nm and 160 nm, respectively. The EQE curves of the corresponding IT-4Cl units in the fabricated detector array are shown below. Figure 3 As shown, there is a significant narrowband response at 800nm.

[0054] Example 2

[0055] (1) In a N2 atmosphere, a PTB7-Th organic donor precursor solution with a concentration of 15 mg / mL was prepared and stirred at 60 °C for 2 h.

[0056] (2) A hole transport layer PEDOT:PSS was spin-coated on an ITO / PET flexible substrate at 4000 rpm and annealed at 140℃ for 15 min.

[0057] (3) Prepare a donor layer film by spin coating at 1200 rpm on the cavity layer and anneal at 100°C for 25 min.

[0058] (4) On the prepared donor layer film, masks with different patterns are sequentially covered, and receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F with a concentration of 10 mg / mL are spin-coated in different areas at a speed of 2000 rpm. The receptor layer array is prepared by annealing at 100℃ for 10 to 15 min.

[0059] (5) A 1 nm thick LiF barrier layer and a 100 nm thick silver electrode were sequentially vacuum-deposited using a mask.

[0060] (6) Using a spectroscopic device, the prepared detector array units were spectrally calibrated, and the spectral response of each detector unit was labeled as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed.

[0061] (7) Measure the response current generated by the detector array of the light to be reconstructed, denoted as I. i I i It is a one-dimensional column vector.

[0062] (8) Reconstruct using the following formula:

[0063]

[0064] Here, F(λ) represents the spectrum to be reconstructed and is a one-dimensional column vector. F(λ) can be obtained by performing the inverse operation on the integral, i.e., F = R. -1 I.

[0065] The transmittance curve of the donor layer PTB7-Th prepared in Example 2 is shown below. Figure 4 As shown, it can effectively filter photons up to 800nm. The PL scan images of the donor layer PTB7-Th and its overlying acceptor layer IT-4Cl are shown below. Figure 5 As shown, the film exhibits uniform luminescence, indicating a good surface morphology. The EQE curves of the corresponding IT-4Cl units in the fabricated detector array are shown below. Figure 6 As shown, it also has a good narrowband response, but the response is slightly higher at 400nm, mainly due to the thinning of the donor layer.

[0066] Example 3

[0067] (1) In a N2 atmosphere, a PTB7-Th organic donor precursor solution with a concentration of 20 mg / mL was prepared and stirred at 60 °C for 2 h.

[0068] (2) A hole transport layer PEDOT:PSS was spin-coated on an ITO / PET flexible substrate at 4000 rpm and annealed at 140℃ for 15 min.

[0069] (3) Prepare a donor layer film by spin coating at 1000 rpm on the cavity layer and anneal at 100°C for 30 min.

[0070] (4) On the prepared donor layer film, masks with different patterns are sequentially covered, and receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F with a concentration of 10 mg / mL are spin-coated in different areas at a speed of 2000 rpm. The receptor layer array is prepared by annealing at 100℃ for 10 to 15 min.

[0071] (5) A 1 nm thick LiF barrier layer and a 100 nm thick silver electrode were sequentially vacuum-deposited using a mask.

[0072] (6) Using a spectroscopic device, the prepared detector array units were spectrally calibrated, and the spectral response of each detector unit was labeled as R. i (λ), Ri (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed.

[0073] (7) Measure the response current generated by the detector array of the light to be reconstructed, denoted as I. i I i It is a one-dimensional column vector.

[0074] (8) Reconstruct using the following formula:

[0075]

[0076] Here, F(λ) represents the spectrum to be reconstructed and is a one-dimensional column vector. F(λ) can be obtained by performing the inverse operation on the integral, i.e., F = R. -1 I.

[0077] The EQE curves of the IT-4Cl unit in the detector array prepared in Example 3 under different voltages are shown below. Figure 7 As shown, this indicates that the detection unit exhibits good response performance under different voltages. The corresponding bright / dark IV curves are shown below. Figure 8 As shown, it has an on / off ratio close to 1000 at -0.5V. The EQE curves of all detection units are as follows. Figure 9 As shown, it has a good narrowband response in the 700-1000nm range, and multispectral detection can be achieved by using the formula.

[0078] Comparative Example 1

[0079] (1) In a N2 atmosphere, a PTB7-Th organic donor precursor solution with a concentration of 20 mg / mL was prepared and stirred at 60 °C for 2 h.

[0080] (2) A hole transport layer PEDOT:PSS was spin-coated on an ITO / PET flexible substrate at 4000 rpm and annealed at 140℃ for 15 min.

[0081] (3) Prepare a donor layer film by spin coating at 2000 rpm on the cavity layer and anneal at 100℃ for 20 min.

[0082] (4) On the prepared donor layer film, masks with different patterns are sequentially covered, and receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F with a concentration of 10 mg / mL are spin-coated in different areas at a speed of 2000 rpm. The receptor layer array is prepared by annealing at 100℃ for 10 to 15 min.

[0083] (5) A 1 nm thick LiF barrier layer and a 100 nm thick silver electrode were sequentially vacuum-deposited using a mask.

[0084] (6) Using a spectroscopic device, the prepared detector array units were spectrally calibrated, and the spectral response of each detector unit was labeled as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed.

[0085] (7) Measure the response current generated by the detector array of the light to be reconstructed, denoted as I. i I i It is a one-dimensional column vector.

[0086] (8) Reconstruct using the following formula:

[0087]

[0088] Here, F(λ) represents the spectrum to be reconstructed and is a one-dimensional column vector. F(λ) can be obtained by performing the inverse operation on the integral, i.e., F = R. -1 I.

[0089] The EQE curve of the IT-4Cl unit in the detector array prepared in Comparative Example 1 is shown below. Figure 10 As shown, it is no longer able to produce a good narrowband response, indicating that the substrate layer is too thin and cannot effectively filter out unwanted photons.

[0090] Comparative Example 2

[0091] This embodiment describes a method for fabricating a miniature flexible multispectral detector, which specifically includes the following steps:

[0092] (1) In a N2 atmosphere, a PTB7-Th organic donor precursor solution with a concentration of 10 mg / mL was prepared and stirred at 60 °C for 2 h.

[0093] (2) A hole transport layer PEDOT:PSS was spin-coated on an ITO / PET flexible substrate at 4000 rpm and annealed at 140℃ for 15 min.

[0094] (3) Prepare a donor layer film by spin coating at 1200 rpm on the cavity layer and anneal at 100°C for 20 min.

[0095] (4) On the prepared donor layer film, masks with different patterns are sequentially covered, and receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F with a concentration of 10 mg / mL are spin-coated in different areas at a speed of 2000 rpm. The receptor layer array is prepared by annealing at 100℃ for 10 to 15 min.

[0096] (5) A 1 nm thick LiF barrier layer and a 100 nm thick silver electrode were sequentially vacuum-deposited using a mask.

[0097] (6) Using a spectroscopic device, the prepared detector array units were spectrally calibrated, and the spectral response of each detector unit was labeled as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed.

[0098] (7) Measure the response current generated by the detector array of the light to be reconstructed, denoted as I. i I i It is a one-dimensional column vector.

[0099] (8) Reconstruct using the following formula:

[0100]

[0101] Here, F(λ) represents the spectrum to be reconstructed and is a one-dimensional column vector. F(λ) can be obtained by performing the inverse operation on the integral, i.e., F = R. -1 I.

[0102] The EQE curves of the IT-4Cl units in the detector array prepared in Comparative Example 2 are as follows: Figure 11 As shown, there is a significant response before 600nm, which can no longer meet the expected requirements, indicating that the donor layer concentration is too low and the thickness is too thin, and it cannot effectively filter out unwanted photons.

[0103] Comparative Example 3

[0104] This embodiment describes a method for fabricating a miniature flexible multispectral detector, which specifically includes the following steps:

[0105] (1) In a N2 atmosphere, a PTB7-Th organic donor precursor solution with a concentration of 30 mg / mL was prepared and stirred at 60 °C for 2 h.

[0106] (2) A hole transport layer PEDOT:PSS was spin-coated on an ITO / PET flexible substrate at 4000 rpm and annealed at 140℃ for 15 min.

[0107] (3) Prepare a donor layer film by spin coating at 1200 rpm on the cavity layer and anneal at 100°C for 20 min.

[0108] (4) On the prepared donor layer film, masks with different patterns are sequentially covered, and receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F with a concentration of 10 mg / mL are spin-coated in different areas at a speed of 2000 rpm. The receptor layer array is prepared by annealing at 100℃ for 10 to 15 min.

[0109] (5) A 1 nm thick LiF barrier layer and a 100 nm thick silver electrode were sequentially vacuum-deposited using a mask.

[0110] (6) Using a spectroscopic device, the prepared detector array units were spectrally calibrated, and the spectral response of each detector unit was labeled as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed.

[0111] (7) Measure the response current generated by the detector array of the light to be reconstructed, denoted as I. i I i It is a one-dimensional column vector.

[0112] (8) Reconstruct using the following formula:

[0113]

[0114] Here, F(λ) represents the spectrum to be reconstructed and is a one-dimensional column vector. F(λ) can be obtained by performing the inverse operation on the integral, i.e., F = R. -1 I.

[0115] The EQE curves of the IT-4Cl units in the detector array prepared in Comparative Example 3 are as follows: Figure 12 As shown, the overall response is weak, indicating that the donor layer is too thick.

Claims

1. A method for fabricating a miniature flexible multispectral detector, characterized in that, Includes the following steps: (1) In a N2 atmosphere, prepare a PTB7-Th organic donor precursor solution with a concentration of 15-20 mg / mL; (2) On an ITO / PET flexible substrate coated with a hole transport layer, an organic donor precursor solution is spin-coated at a speed of 1000-1200 rpm and annealed at 100°C for 20-30 min to prepare a donor layer film. (3) Masks with different patterns were sequentially covered on the donor layer film. 8-12 mg / mL of 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F receptor material solutions were spin-coated in different areas at a speed of 1900-2100 rpm. The solutions were then annealed at 100℃ for 10-15 min to prepare the receptor layer array. (4) A miniature flexible multispectral detector was fabricated by vacuum evaporating a LiF barrier layer and a silver electrode on the acceptor layer array using a mask.

2. The preparation method according to claim 1, characterized in that, In step (1), the thickness of the donor layer is 380 nm.

3. The preparation method according to claim 1, characterized in that, In step (1), PTB7-Th is dissolved in chlorobenzene and stirred at 50-70°C for more than 2 hours to prepare a PTB7-Th organic donor precursor solution.

4. The preparation method according to claim 1, characterized in that, In step (2), the hole transport layer is PEDOT:PSS, and the spin coating speed during the hole transport layer preparation process is 4000 rpm, followed by annealing at 140℃ for 15 min.

5. The preparation method according to claim 1, characterized in that, In step (3), the thickness of the receptor layer is 160 nm.

6. The preparation method according to claim 1, characterized in that, In step (3), the rotation speed is 2000 rpm.

7. The preparation method according to claim 1, characterized in that, In step (3), receptor materials 6TBA, IT-4Cl, 4TIC-4F and 6TIC-4F are dissolved in chlorobenzene and stirred at room temperature for more than 2 hours to prepare receptor material solutions.

8. The preparation method according to claim 1, characterized in that, In step (4), the thickness of the LiF barrier layer is 1 nm and the thickness of the silver electrode is 100 nm.

9. A miniature flexible multispectral detector prepared by any one of the preparation methods according to claims 1 to 8.

10. The spectral recognition algorithm based on the miniature flexible multispectral detector according to claim 9, characterized in that, Includes the following steps: (1) Using spectroscopic equipment, the spectral calibration of the miniature flexible multispectral detector array unit is performed, and the spectral response of each detector unit is denoted as R. i (λ), R i (λ) is an m×m matrix, where λ represents the wavelength range of the spectrum to be reconstructed; (2) Measure the response current generated by the detector array to the spectrum to be reconstructed, denoted as I. i I i It is a one-dimensional column vector; (3) Reconstruct using the following formula: Where F(λ) represents the spectrum to be reconstructed, and is a one-dimensional column vector, F(λ) can be obtained by performing the inverse operation of the integral, i.e., F = R - 1 I.

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