Full-color Micro-LED chip array based on perovskite material and preparation method thereof

Abstract

The invention belongs to the field of display, and discloses a full-color Micro-LED chip array based on a perovskite material and a preparation method thereof.The full-color Micro-LED chip array comprises perovskite Micro-LED chips of multiple colors, each perovskite Micro-LED chip of the color comprises a functional layer and an electrode, the functional layer comprises a Micro-LED bottom transmission layer, a Micro-LED active layer and a Micro-LED top transmission layer, the electrode is arranged on the Micro-LED bottom transmission layer, the micro-LED active layer is arranged on the Micro-LED top transmission layer, and the electrode is arranged on the Micro-LED bottom transmission layer. And perovskite Micro-LED active layers with other colors are obtained on the monochromatic perovskite Micro-LED active layer through a halogen anion exchange method. According to the full-color perovskite Micro-LED, a display screen meeting the resolution can be directly prepared through substrate patterning, compared with a Micro-LED chip array prepared based on mass transfer, the preparation cost is low, and high-throughput production of the perovskite Micro-LED chip array is easy to achieve.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a perovskite material integrated full-color Micro-LED chip array and a preparation method thereof. Background Art

[0002] Micro light-emitting diodes (Micro LEDs) have been regarded as the next generation of display technology, which has significant advantages in resolution, brightness and response time. At present, due to the differences in the growth process of the Micro-LED light-emitting layer and the driving substrate, the realization of a full-color Micro-LED screen requires the use of mass transfer technology (massive chip mass transfer process) to transfer the prepared Micro-LED to the driving circuit substrate. Taking a 4K TV as an example, up to 24 million chips need to be transferred. The transfer efficiency, accuracy and yield issues during the transfer process will focus on the display performance after the transfer. Researchers have tried to focus on the transfer head assembly (US8349116B1, US9255001B2) and improve the tether anchor point to weaken the connection between the device and the native substrate (US9161448B2, US20220181185A1), but the existing equipment, process and technology still cannot meet the needs of Micro-LED mass production. Not only is the production cost high, but the production efficiency is also low. Therefore, mass transfer technology limits the commercial application of full-color Micro-LED.

[0003] In recent years, metal halide perovskites have attracted much attention due to their high photoluminescence quantum efficiency (PLQE), high charge mobility, and easy solution processing, and are considered to have great potential for realizing efficient and high-brightness Micro-LEDs. In addition, the inherent polycrystalline nature of perovskite films limits their charge diffusion length, which can reduce the impact of sidewall defects and is beneficial to the realization of efficient Micro-LEDs. Although there have been attempts to manufacture full-color perovskite Micro-LEDs by inkjet printing (Inkjet-printed full-color matrix quasi-two-dimensional perovskite lightemitting diodes, ACS Appl. Mater. Interfaces, 2021, 13, 41773-41781), it is only suitable for small-scale production due to its poor scalability, low throughput, and high cost. The controlled growth process of substrate pre-patterning can produce high-quality perovskite arrays, and its low cost can also meet the scalability and high-throughput production requirements of display applications (Ultrahighcolor rendering in RGB perovskite micro-light emitting diode arrays with resonance-enhanced photon recycling for next generation displays. Adv. Opt. Mater., 2022, 10, 2101642). Therefore, the full-color Micro-LED chip array with pre-patterning of perovskite material integrated substrate has broad application prospects in the field of ultra-high-definition display technology. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a full-color Micro-LED chip array based on perovskite. The main feature of this display array is that the perovskite full-color Micro-LED chip array is obtained by using the halogen anion exchange method. Compared with the Micro-LED chip array prepared based on mass transfer, its preparation cost is lower, and it is expected to achieve high-throughput production of perovskite Micro-LED chip arrays.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned perovskite full-color Micro-LED chip array.

[0006] The object of the present invention is achieved in the following ways:

[0007] A full-color Micro-LED chip array based on perovskite materials, the array includes perovskite Micro-LED chips of multiple colors, firstly prepare a monochrome perovskite Micro-LED chip, and then obtain Micro-LED chips of other colors by halogen anion exchange. Each color perovskite Micro-LED chip includes a functional layer and an electrode, and the functional layer includes a Micro-LED bottom transmission layer, a Micro-LED active layer and a top transmission layer. Specifically: the present invention obtains a perovskite Micro-LED active layer of other colors by halogen anion exchange on a monochrome perovskite Micro-LED active layer.

[0008] Preferably, in the preparation of the full-color Micro-LED active layer, the halogen anion exchange method is to prepare the anion exchange material on the monochrome perovskite Micro-LED active layer by a solution method or a vapor deposition method, thereby achieving anion exchange;

[0009] Among them, the anion exchange material in the solution method is composed of one or more materials, and the mass fraction of the anion exchange material is 0.05% to 20%; the preferred mass fraction is 0.1% to 4%; the vapor deposition method is to deposit anion exchange material with a thickness of 1nm-200nm onto the monochrome perovskite Micro-LED active layer to achieve anion exchange.

[0010] Preferably, the anion exchange material is one or more of TPPB, PBAB, PBAC, TPPC, HBr, HI, HBr, CH3NH3I, CH3NH3Br, CH3NH3Cl, CH(NH2)2Br, CH(NH2)2I, CH(NH2)2Cl, CsBr, CsI, CsCl, RbBr, RbCl, RbI, or the raw material halide of nucleophilic substitution reaction C2H3Cl3, CH2Cl2, C2H2Cl4, CHI3, CHBr3, CHCl3, C2H4I2, C2H4Br2, C2H4Cl2, C3H7Br, C3H6I2, C3H6Br2, C3H6Cl2, C4H8I2, C4H8Br2, C4H8Cl2, C4H9Br, C5H 10 I2, C5H 10 Br2、C5H 10 Cl2, C6H4Cl2, C6H5Br, C7H7Cl, C7H6ClF, C9H9Cl and nucleophile C 12 H 27 P.C. 24 H 51 P.C. 18 H 15 P, C6H 15N, C9H 21 N, C 12 H 27 N, C 15 H 33 N etc. reaction mixed solution.

[0011] The above-mentioned full-color Micro-LED chip array is preferably a three-color Micro-LED chip array, and the most preferred is a red, green and blue full-color perovskite Micro-LED chip array.

[0012] The above-mentioned full-color Micro-LED chip array based on perovskite material is prepared by the following steps:

[0013] S1, preparing a full-color perovskite Micro-LED array pattern on a substrate;

[0014] S2, preparing the bottom transmission layer on the full-color perovskite Micro-LED array pattern;

[0015] S3, preparing an arrayed monochrome perovskite Micro-LED active layer on the bottom transmission layer;

[0016] S4, spin coating photoresist on the arrayed single-color perovskite Micro-LED active layer or using electron beam lithography to expose part of the single-color perovskite Micro-LED active layer; realizing other color perovskite Micro-LED active layers on the exposed part of the single-color perovskite Micro-LED active layer by anion exchange, thereby obtaining an arrayed two-color perovskite Micro-LED active layer;

[0017] S5. Spin-coating photoresist on the arrayed two-color perovskite Micro-LED active layer or using electron beam lithography to expose a portion of the single-color perovskite Micro-LED active layer; and realizing a third-color perovskite Micro-LED active layer by anion exchange on the exposed portion of the single-color perovskite Micro-LED active layer;

[0018] S6. Exposing the three-color perovskite Micro-LED active layer by debonding; sequentially preparing the full-color Micro-LED top transmission layer on the full-color perovskite Micro-LED active layer;

[0019] S7, preparing a metal electrode on the top transport layer;

[0020] S8. Encapsulate full-color perovskite Micro-LED to obtain a full-color Micro-LED chip array.

[0021] The preparation of the transport layer in S2 comprises the following steps:

[0022] Spin-coat the transport layer material onto the full-color perovskite Micro-LED array pattern at a speed of 1000 to 8000 rpm and bake on a hot plate;

[0023] Alternatively, the transport layer material is deposited onto the full-color perovskite Micro-LED array pattern by evaporation;

[0024] The preparation of the arrayed monochrome perovskite Micro-LED active layer in S3 includes the following steps:

[0025] The perovskite precursor solution is dropped onto the arrayed bottom Micro-LED transport layer and spin-coated at a speed of 1000-8000 rpm, and annealed at 40-200°C;

[0026] Alternatively, the perovskite precursor is deposited onto the arrayed bottom Micro-LED transport layer by multi-source co-evaporation to obtain an arrayed monochrome Micro-LED active layer with a thickness of 5-300nm.

[0027] Preferably, the perovskite material used in the monochrome perovskite Micro-LED active layer is A2B N-1 M N X 3N+1 or BMX3; wherein A is a long-chain organic cation, B is a monovalent cation, M is a divalent metal cation, X is any one or more of the halogen elements Cl, Br, I, N (N = 1, 2, ..., ∞) is the number of layers of the inorganic skeleton of the perovskite material, and the perovskite material is further preferably A2B N-1 M N X 3N+1 , N = 1, 2, ... 50;

[0028] Or the perovskite material is one or more of the perovskite derivatives Cs4SnBr6, Cs4SnI6, Cs4SnCl6, Cs3Bi2I9, Cs3Sb2I9, Cs3Sb2Br9, Cs3Sb2Cl9, Cs5Cu3Cl6I2, Cs5Cu3Cl7I, CsCu2Cl3, CsCu2I3, CsCu2Br3, Ru2CuBr3, Ru2CuCl3, K2CuBr3, CsCu2I2Cl, CsCu2I2Br, CsCu2Br2I, CsCu2Br2Cl, CsCu2Cl2I, CsCu2Cl2Br, and Cs3Bi2Br9.

[0029] Most preferably, the perovskite material used in the monochromatic perovskite Micro-LED active layer is BM(I x Br y Cl 1-x-y)3, wherein B is one or more of Cs, FA, Rb, GA, and MA, M is one or more of Pb and Sn, and 0≤x≤1, 0≤y≤1.

[0030] Preferably, the perovskite full-color Micro-LED chip can be a regular structure or a trans structure. The transport layer is a Micro-LED electron transport layer or a Micro-LED hole transport layer.

[0031] Preferably, the preparation of the monochromatic Micro-LED hole transport layer comprises the following steps:

[0032] PEDOT:PSS, PVK, PTAA, TPD or TFB is spin-coated on the monochrome Micro-LED bottom electrode array and baked on a hot stage.

[0033] Preferably, the specific preparation of the arrayed monochrome Micro-LED active layer includes the following steps:

[0034] A2B N-1 M N X 3N+1 Or the BMX3 perovskite precursor solution is dropped onto the arrayed hole transport layer, spin-coated at a speed of 1000-8000 rpm, and annealed at 40-200°C;

[0035] Alternatively, a multi-source co-evaporation method is used to evaporate A2B with a thickness of 5nm-300nm. N-1 M N X 3N+1 Or the BMX3 perovskite precursor material is deposited onto the monochrome Micro-LED hole transport layer to obtain a monochrome Micro-LED active layer.

[0036] Preferably, the A2B N-1 M N X 3N+1 Or the BMX3 perovskite precursor solution is prepared by dissolving AX, BX and MX in a solvent at a molar ratio of 1-100:1-100:1-100, with a mass fraction of 1%-50%; preferably, the molar ratio of AX, BX and MX is 1-10:1-10:1-10, with a mass fraction of 5%-25%. The preferred solvent is N,N-dimethylformamide and dimethyl sulfoxide.

[0037] Preferably, the specific preparation of the Micro-LED electron transport layer includes the following steps:

[0038] The TPBi and TmPyPB electron transport layers are evaporated or spin-coated on the full-color Micro-LED active layer.

[0039] Alternatively, the Micro-LED electron transport layer is prepared on the bottom electrode array, and the preparation includes the following steps:

[0040] Spin-coat ZnO or SnO2 onto the Micro-LED array pattern and bake it on a hot plate;

[0041] Alternatively, ZnO or SnO2 is deposited onto the Micro-LED bottom electrode array by ALD.

[0042] Preferably, the preparation of the Micro-LED hole transport layer includes the following steps:

[0043] The micro-LED hole transport layer is prepared on the active layer or the bottom electrode array, comprising the following steps: spin coating the TFB, TPD, PTAA or PVK solution on the micro-LED active layer or the bottom electrode array at a rotation speed of 1000-8000 rpm;

[0044] Alternatively, TAPC or TCTA is evaporated onto the Micro-LED active layer or the bottom electrode array.

[0045] The method for preparing the full-color Micro-LED chip array based on perovskite material comprises the following steps:

[0046] S1, preparing a full-color perovskite Micro-LED array pattern on a substrate;

[0047] S2, preparing the bottom transmission layer on the full-color perovskite Micro-LED array pattern;

[0048] S3, preparing an arrayed monochrome Micro-LED active layer on the bottom transmission layer;

[0049] S4, spin coating photoresist on the arrayed single-color perovskite Micro-LED active layer or using electron beam lithography to expose part of the single-color perovskite Micro-LED active layer; realizing other color perovskite Micro-LED active layers on the exposed part of the single-color perovskite Micro-LED active layer by anion exchange, thereby obtaining an arrayed two-color perovskite Micro-LED active layer;

[0050] S5. Spin-coating photoresist on the arrayed two-color perovskite Micro-LED active layer or using electron beam lithography to expose a portion of the single-color perovskite Micro-LED active layer; and realizing a third-color perovskite Micro-LED active layer by anion exchange on the exposed portion of the single-color perovskite Micro-LED active layer;

[0051] S6. Exposing the three-color perovskite Micro-LED active layer by debonding; sequentially preparing the full-color Micro-LED top transmission layer on the full-color perovskite Micro-LED active layer;

[0052] S7, preparing a metal electrode on the top transport layer;

[0053] S8. Encapsulate full-color perovskite Micro-LED to obtain a full-color Micro-LED chip array.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0055] (1) The present invention integrates full-color perovskite LEDs to meet the requirements of high efficiency, high brightness and high color purity in Micro-LED applications.

[0056] (2) The full-color perovskite array in the Micro-LED array is achieved through ion exchange and does not require transfer; and the preparation process can effectively avoid high-cost equipment such as dry etching and epitaxial method, greatly reducing the cost of Micro-LED preparation.

[0057] (3) The prepared perovskite full-color Micro-LED can maintain high efficiency under high current conditions, and its efficiency is still comparable to that of large-area devices when the pixel size is 40μm. It does not suffer from the serious drop in efficiency of traditional III-V materials when the size is reduced.

[0058] Therefore, the full-color Micro-LED chip array based on perovskite materials of the present invention has the advantages of lower preparation cost, higher color purity, no obvious sidewall effect, and higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Transparent circuit board prepared in Example 1 of the present invention

[0060] Figure 2 The arrayed pattern prepared on the transparent circuit board in Example 1 of the present invention

[0061] Figure 3 This is the preparation diagram of the hole transport layer of the full-color perovskite Micro-LED in Example 1 of the present invention

[0062] Figure 4 This is a diagram showing the preparation of the active layer of a monochrome green light perovskite Micro-LED according to Example 1 of the present invention.

[0063] Figure 5 PMMA packaging diagram before the active layer of the blue perovskite Micro-LED of Example 1 of the present invention is prepared Figure 6The array pattern of the blue light perovskite Micro-LED active layer exposed in Example 1 of the present invention

[0064] Figure 7 This is a diagram showing the preparation of the active layer of a blue light perovskite Micro-LED based on green light in Example 1 of the present invention.

[0065] Figure 8 This is a structural diagram of the active layer preparation of green and blue perovskite Micro-LEDs in Example 1 of the present invention

[0066] Fig. 9 PMMA packaging diagram before preparation of the active layer of the red perovskite Micro-LED in Example 1 of the present invention Fig.10 The array pattern of preparing the red light perovskite Micro-LED active layer exposed in Example 1 of the present invention

[0067] Fig.11 This is a diagram showing the preparation of the active layer of a red light perovskite Micro-LED based on green light and blue light in Example 1 of the present invention.

[0068] Fig.12 This is a structural diagram of the active layer preparation of the red, green and blue full-color perovskite Micro-LED in Example 1 of the present invention

[0069] Fig.13 This is a diagram of the preparation of the full-color Micro-LED electron transport layer in Example 1 of the present invention

[0070] Fig.14 This is a diagram of the preparation of the metal electrode of the full-color Micro-LED in Example 1 of the present invention

[0071] Fig.15 This is a full-color Micro-LED packaging diagram of Example 1 of the present invention

[0072] Fig.16 JV curve and LV curve of green, blue and red 40μm micro-LED in the full-color device of Example 1 of the present invention

[0073] Fig.17 J-EQE curves of green, blue and red 40 μm micro-LEDs in the full-color device of Example 1 of the present invention

[0074] Fig.18 The normalized spectra of green, blue and red 40μm micro-LEDs at 5V in the full-color device of Example 1 of the present invention are shown in FIG.

[0075] Fig.19 Transparent circuit board prepared in Example 4 of the present invention

[0076] Fig. 20 The arrayed pattern prepared on the transparent circuit board in Example 4 of the present invention

[0077] Fig.21 The bottom electrode array pattern of the transparent substrate is exposed by wet etching in Example 4 of the present invention.

[0078] Fig. 22 This is the full-color Micro-LED bottom electrode array pattern of Example 4 of the present invention

[0079] Fig.23 Figure 4 shows the isolation layer SiO2 in Example 4 of the present invention.

[0080] Fig.24 Figure 4 shows the isolation layer SiO2+PMMA in Example 4 of the present invention.

[0081] Fig.25 This is the isolation layer SiO2+PMMA array diagram in Example 4 of the present invention

[0082] Fig.26 The isolation layer SiO2 array diagram in Example 4 of the present invention

[0083] Fig. 27 Preparation diagram of the hole transport layer of the perovskite Micro-LED in Example 4 of the present invention

[0084] Fig.28 This is a diagram showing the preparation of the active layer of the monochrome green light perovskite Micro-LED in Example 4 of the present invention.

[0085] Fig.29 This is a structural diagram of the active layer preparation of the red, green and blue full-color perovskite Micro-LED in Example 4 of the present invention

[0086] Fig.30 This is a diagram of the preparation of the full-color Micro-LED electron transport layer in Example 4 of the present invention

[0087] Fig.31 This is a diagram of the preparation of the metal electrode of the full-color Micro-LED in Example 4 of the present invention

[0088] Fig.32 This is a full-color Micro-LED packaging diagram of Example 4 of the present invention

[0089] Fig.33 This is a diagram showing the preparation of the bottom transmission layer of the full-color perovskite Micro-LED in Example 5 of the present invention.

[0090] Fig.34 This is a diagram showing the preparation of the active layer of the monochrome green light perovskite Micro-LED in Example 5 of the present invention.

[0091] Fig.35This is the full-color Micro-LED active layer array of Example 5 of the present invention

[0092] Fig.36 This is a diagram showing the preparation of the top transport layer of the full-color perovskite Micro-LED in Example 5 of the present invention.

[0093] Fig.37 This is a diagram of the preparation of the metal electrode of the full-color Micro-LED in Example 5 of the present invention.

[0094] Fig.38 This is a full-color Micro-LED packaging diagram of Example 5 of the present invention

[0095] Fig.39 The cross-section and light-emitting area SEM images of the red light Micro-LED film in Example 5 of the present invention at a lateral size of 20 μm DETAILED DESCRIPTION

[0096] The present invention is further explained below by specific examples:

[0097] Example 1: A formal perovskite full-color Micro-LED array is prepared by sharing the bottom electrode and solution-based ion exchange.

[0098] like Figure 1-15 In the figure, 1 is a transparent substrate; 2 is ITO conductive glass; 3 is an insulating layer; 4 is a bottom transmission layer; 5 is a green light Micro-LED active layer; 6 is a mask layer; 7 is a blue light anion exchange solution precursor; 8 is a blue light Micro-LED active layer; 9 is a red light anion exchange precursor solution; 10 is a red light Micro-LED active layer; 11 is a top transmission layer; 12 is a full-color Micro-LED metal electrode; 13 is a packaging material layer.

[0099] Step 1, preparation of full-color perovskite Micro-LED array pattern: Spin-coat a photoresist (SU8) with a thickness of 200 nm on the cleaned ITO conductive glass, and develop after exposure to expose the full-color perovskite Micro-LED array pattern, such as Figure 1 , 2 As shown;

[0100] Step 2: Preparation of the bottom transport layer of full-color perovskite Micro-LED, i.e., the hole transport layer: Figure 3 As shown, 30 microliters of a 10-20 wt% PEDOT:PSS aqueous solution, a 1-20 mg / ml PVK, a 1-20 mg / ml PTAA, or a 1-10 mg / ml TFB solution were spin-coated on the exposed Micro-LED bottom electrode array at 4000 rpm, and baked on a 100°C hot stage for 10 minutes;

[0101] Step 3, preparation of green light Micro-LED active layer: Take 30 μl of CsPbBr3 solution prepared by dissolving CsBr, PbBr2, PbCl2, and TPPB in a molar ratio of 1.4:0.09:0.09:0.075 in a solvent N,N-dimethylformamide with a mass fraction of 10 wt%, drop it on the Micro-LED hole transport layer, spin-coat at 6000 rpm for 45 seconds, and anneal at 130 ° C for 10 minutes. Figure 4 As shown;

[0102] Step 4: Preparation of blue and green Micro-LED active layers: Figure 5 , 30 μl of PMMA photoresist was spin-coated on the exposed green light Micro-LED active layer at a speed of 4000 rpm and an acceleration of 1000 rpm, and annealed at 80°C for 3 min; Figure 6 , at a dose of 150μC / cm 2 , the green light Micro-LED array pattern was exposed after electron beam etching and development at an accelerating voltage of 20kV; finally, 30 microliters of TPPC+PBAC solution prepared in isopropyl alcohol (IPA) with a concentration of 1-10mg / ml and a molar ratio of 2:1 was dripped onto the exposed green light Micro-LED, and annealed at 130℃ for 30min. Figure 7 As shown;

[0103] Step 5: Preparation of red, green and blue Micro-LED active layers: Figure 8 , 9 As shown, PMMA was removed with toluene, chlorobenzene, chloroform, and dichloromethane, and 30 microliters of PMMA photoresist was spin-coated on the exposed green and blue Micro-LED active layers at a rotation speed of 4000 rpm and an acceleration of 1000 rpm, and annealed at 80°C for 3 minutes; Fig.10 , at a dose of 150μC / cm 2 , the pattern of preparing the red light Micro-LED array was exposed after electron beam etching and development at an accelerating voltage of 20 kV; finally, 30 microliters of TPPI solution prepared in isopropyl alcohol (IPA) with a concentration of 1 to 10 mg / ml was dripped onto the exposed green light Micro-LED active layer, and annealed at 130°C for 30 minutes. Fig.11 , 12 As shown;

[0104] Step 6, preparation of full-color Micro-LED electron transport layer: Fig.12 , 13As shown, PMMA is removed by toluene, chlorobenzene, chloroform, and dichloromethane to expose the activity of the three primary colors of red, green, and blue Micro-LEDs; and SnO2 and ZnO are deposited with a thickness of 30nm by ALD, or TPBi and TmPyPb are deposited with a thickness of 45nm by evaporation using a mask.

[0105] Step 7, preparation of full-color Micro-LED metal electrodes: Fig.14 As shown, the sample was transferred to a thermal evaporation device and evaporation was performed through a mask at a pressure of 4×10 -4 3nm LiF and 70nm Al were deposited sequentially under Pa conditions;

[0106] Step 8, full-color Micro-LED packaging: Fig.15 As shown, the chip is encapsulated using epoxy resin, polyimide, etc.

[0107] Device Characterization:

[0108] The green, blue and red 40 micron micro-LEDs in the full-color device prepared in Example 1 were characterized, and the results obtained are as follows Fig.16 , 17 , 18. The full-color Micro-LED device has a green light emission center wavelength of 520nm, a blue light emission center wavelength of 478nm, and a red light emission center wavelength of 688nm (as shown in FIG. Fig.18 ), the half-peak width of all emission peaks is less than 50nm, which can effectively meet the color purity requirements of Micro-LED applications. Green, blue and red micro-LEDs can still maintain EQE of 6.69%, 2.16% and 7.12% when the lateral size is 40μm (such as Fig.16 , 17 ).

[0109] Example 2: Preparation of a formal perovskite full-color Micro-LED array by sharing the bottom electrode and steam ion exchange

[0110] Similar to Example 1, the difference is that when preparing the blue and red light Micro-LED active layers by anion exchange, the anion exchange material is vaporized at normal pressure, and the anion exchange material is deposited on the blue and red light Micro-LED patterns by steam method and annealed; or the sample is transferred to a thermal evaporation device at a pressure of 4×10 -4 Under Pa conditions, anion exchange materials are deposited onto the blue and red Micro-LED patterns, respectively, and annealed to achieve this;

[0111] The specific steps of Example 1 are as follows:

[0112] In step 4 and step 5, the photoresist (PMMA) mask is replaced by a reticle mask, and the anion exchange material is deposited on the blue and red Micro-LED patterns respectively by vaporizing the anion material at normal pressure and annealing; or the reticle mask is used to transfer the sample to a thermal evaporation device at a pressure of 4×10 -4 Under Pa conditions, anion exchange materials are deposited onto the blue and red Micro-LED patterns, respectively, and annealed to achieve this;

[0113] There is no PMMA photoresist solution stripping step in step 4, step 5 and step 6.

[0114] Example 3 Preparation of trans-perovskite full-color Micro-LED array by sharing bottom electrode and solution-based ion exchange

[0115] Structure Figure 1-15 In the figure, 1 is a transparent substrate; 2 is ITO conductive glass; 3 is an insulating layer; 4 is a bottom transmission layer; 5 is a green light Micro-LED active layer; 6 is a mask layer; 7 is a blue light anion exchange solution precursor; 8 is a blue light Micro-LED active layer; 9 is a red light anion exchange precursor solution; 10 is a red light Micro-LED active layer; 11 is a top transmission layer; 12 is a full-color Micro-LED metal electrode; 13 is a packaging material layer.

[0116] Step 1, preparation of full-color perovskite Micro-LED array pattern: Spin-coat a photoresist (SU8) with a thickness of 200 nm on the cleaned ITO conductive glass, and develop after exposure to expose the full-color perovskite Micro-LED array pattern, such as Figure 1 , 2 As shown;

[0117] Step 2: Preparation of the bottom transport layer of the inverse full-color perovskite Micro-LED, i.e., the electron transport layer: Figure 3 As shown, SnO2 with a thickness of 30 nm or ZnO with a thickness of 30 nm is deposited;

[0118] Alternatively, TPBi with a thickness of 45 nm or TmPyPb with a thickness of 45 nm is deposited by thermal evaporation;

[0119] Step 3, preparation of green light Micro-LED active layer: Take 30 μl of CsPbBr3 solution prepared by dissolving CsBr, PbBr2, PbCl2, and TPPB in a molar ratio of 1.4:0.09:0.09:0.075 in solvent N,N-dimethylformamide with a mass fraction of 10%, drop it on the Micro-LED electron transport layer, spin coat at a speed of 6000 rpm and an acceleration of 6000 rpm for 45 seconds, and anneal at 130°C for 10 minutes. Figure 4 As shown;

[0120] Step 4: Preparation of blue and green Micro-LED active layers: Figure 5 , 30 μl of PMMA photoresist was spin-coated on the exposed green light Micro-LED active layer at a speed of 4000 rpm and an acceleration of 1000 rpm, and annealed at 80°C for 3 min; Figure 6 , at a dose of 150μC / cm 2 , the blue light Micro-LED array pattern was exposed after electron beam etching at an acceleration voltage of 20 kV and development; finally, 30 microliters of the prepared nucleophilic substitution reaction raw material halide C7H7Cl and nucleophilic reagent C9H 21 P was dripped onto the exposed green light Micro-LED in a volume ratio of 3000:1 to 1000:1 and annealed at 130°C for 10 min. Figure 7 As shown;

[0121] Step 5: Preparation of red, green and blue Micro-LED active layers: Figure 8 , 9 As shown, PMMA was removed with toluene, chlorobenzene, chloroform, and dichloromethane, and 30 microliters of PMMA photoresist was spin-coated on the exposed green and blue Micro-LED active layers at a rotation speed of 4000 rpm and an acceleration of 1000 rpm, and annealed at 80°C for 3 minutes; Fig.10 , at a dose of 150μC / cm 2 , the pattern of preparing the red light Micro-LED array was exposed after electron beam etching and development at an accelerating voltage of 20 kV; finally, 30 microliters of the prepared nucleophilic substitution reaction raw material halide C7H7I and nucleophilic reagent C9H 21 A mixed solution with a volume ratio of 3000:1 to 100:1 was dripped onto the exposed green light Micro-LED active layer and annealed at 130°C for 30 min. Fig.11 , 12 As shown;

[0122] Step 6: Preparation of the top transport layer of full-color Micro-LED, i.e., the hole transport layer: Fig.12 , 13As shown, PMMA is removed with toluene, chlorobenzene, chloroform or dichloromethane to expose the active layer of the three primary colors of red, green and blue Micro-LEDs; 30 microliters of PVK with a concentration of 1 to 20 mg / ml, PTAA with a concentration of 1 to 20 mg / ml or TFB solution with a concentration of 1 to 20 mg / ml are spin-coated on the exposed Micro-LED active layer array at a speed of 4000 rpm and an acceleration of 4000 rpm for 45 seconds, and then baked on a hot stage at 100°C for 10 minutes;

[0123] Step 7, preparation of full-color Micro-LED metal electrodes: Based on the above, the sample is transferred to a thermal evaporation device and evaporation is performed through a mask at a pressure of 4×10 -4 4.5nm MoO was deposited successively under Pa conditions x with 70nm Ag or Au;

[0124] Step 8, full-color Micro-LED packaging: Fig.15 As shown, the chip is encapsulated using epoxy resin, polyimide, etc.

[0125] Example 4: Preparation of a formal perovskite full-color Micro-LED array by sharing the top electrode and solution-based ion exchange

[0126] like Figure 19 to Figure 32 In the figure, 14 is a transparent substrate; 15 is a full-color perovskite Micro-LED bottom electrode; 16 is a photoresist mask layer; 17 is a bottom electrode isolation layer SiO2; 18 is a hole transport layer; 19 is a green light Micro-LED active layer; 20 is a blue light Micro-LED active layer; 21 is a red light Micro-LED active layer; 22 is an electron transport layer; 23 is a full-color Micro-LED metal electrode; 24 is a packaging material layer.

[0127] Step 1: Preparation of full-color perovskite Micro-LED bottom electrode array: Fig.19 , 20 As shown, a photoresist with a thickness of 200 nm is spin-coated on the cleaned ITO conductive glass, and the ITO is exposed by development after exposure; wet etching is performed until the transparent substrate is exposed, and an arrayed bottom electrode array is obtained after the resist is removed, as shown in FIG. Fig.21 , 22 As shown;

[0128] Alternatively, the bottom electrode array is obtained by magnetron sputtering through a mask plate.

[0129] Step 2, preparation of the isolation layer of the bottom electrode array of full-color perovskite Micro-LED: a layer of SiO2 (such as Fig.23As shown), and spin-coat a photoresist with a thickness of about 2 microns (as shown Fig.21 As shown), after exposure, the SiO2 is exposed (as shown Fig.25 As shown), wet etching is performed until the transparent substrate is exposed, and the exposed SiO2 array is obtained after stripping (as shown Fig.25 ), and then wet-etching until the array bottom electrode is exposed (as shown in Fig.26 shown).

[0130] Alternatively, etching is performed by dry etching until the bottom electrode array is exposed.

[0131] Steps 3 to 9 are similar to steps 2 to 8 in Example 1, and finally a packaged full-color perovskite Micro-LED array is obtained.

[0132] Example 5: Positive and negative combination perovskite full-color Micro-LED array

[0133] Structure Figure 19-26 , 33-38, in the figure, 14 is a transparent substrate; 15 is a full-color perovskite Micro-LED bottom electrode; 16 is a photoresist mask layer; 17 is a bottom electrode isolation layer SiO2; 18 is a hole transport layer; 19 is a green light Micro-LED active layer; 20 is a blue light Micro-LED active layer; 21 is a red light Micro-LED active layer; 22 is an electron transport layer; 23 is a full-color Micro-LED metal electrode; 24 is a packaging material layer.

[0134] Steps 1 and 2 are the same as in Example 4;

[0135] Step 3: Preparation of full-color Micro-LED bottom transmission layer: Fig.33 As shown, the bottom transport layer of blue and green Micro-LEDs, i.e., the hole transport layer, is prepared by transferring the sample to a thermal evaporation device, using a mask plate, and evaporating the sample under a pressure of 4×10 -4 NiO with a thickness of 30 nm was deposited under Pa conditions. x Preparation of blue and green Micro-LED hole transport layers;

[0136] Or a mask plate mask, magnetron sputtering method is used to deposit 30nm thick NiO x Deposited onto the arrayed electrodes of blue and green Micro-LEDs;

[0137] Preparation of the bottom transport layer of red light Micro-LED, i.e. the electron transport layer:

[0138] A mask plate is used to deposit 30nm SnO2 or 30nm ZnO onto the bottom electrode array of the red light Micro-LED to prepare an electron transport layer by ALD;

[0139] Or a mask plate mask, depositing 45nm thick TPBi or 45nm TmPyPb on the red light Micro-LED bottom electrode array by thermal evaporation to prepare an electron transport layer;

[0140] Step 4, preparation of monochromatic green light Micro-LED active layer: Take 30 μl of CsPbBr3 solution prepared by dissolving CsBr, PbBr2, PbCl2, and TPPB in a molar ratio of 1.4:0.09:0.09:0.075 in solvent N,N-dimethylformamide, with a mass fraction of 10%, and drop it on the bottom transmission layer of Micro-LED, spin-coat at a speed of 6000 rpm and an acceleration of 6000 rpm for 45 seconds, and anneal at 130 ° C for 10 minutes. Fig.34 As shown;

[0141] Step 5, preparation of blue light and red light Micro-LED active layers: the same as steps 4 and 5 in Example 1, to obtain blue light and red light Micro-LED active layers, such as Fig.35 The prepared full-color Micro-LED active layer array;

[0142] Step 6: Preparation of full-color Micro-LED top transmission layer:

[0143] like Fig.33 Preparation of the top transport layer of blue and green Micro-LEDs, i.e., the electron transport layer: The pressure in the chamber is 4×10 -4 TPBi with a thickness of 45 nm was deposited under Pa conditions to prepare the electron transport layer of blue and green light Micro-LEDs.

[0144] Preparation of the top transport layer of red light Micro-LED, i.e. the hole transport layer:

[0145] The mask plate is used to deposit 30nm NiO x Deposited onto the red light Micro-LED active layer.

[0146] Step 7: Preparation of full-color Micro-LED metal electrodes: Fig.37 As shown,

[0147] Preparation of metal electrodes for blue and green Micro-LEDs:

[0148] The sample was transferred to a thermal evaporation apparatus and the mask was placed under a pressure of 4 × 10 -4 The thickness of LiF and Al deposited under Pa conditions was 3nm and 70nm respectively;

[0149] Preparation of metal electrodes for red light Micro-LED:

[0150] The sample was transferred to the thermal evaporation equipment, the mask was placed on the reticle, and the chamber pressure was 4 × 10 -4 MoO with a thickness of 3 nm was deposited under Pa conditions. x and 70nm Ag / Au.

[0151] Step 8: Full-color Micro-LED chip packaging: Fig.38 As shown, the chip is encapsulated using epoxy resin, polyimide, etc.

[0152] Thin film characterization:

[0153] The red light film in the full-color device prepared in Example 5 was characterized, and the results obtained were as follows: Fig.39 shown.

[0154] The grains of the red light film at the side wall grow completely, are indistinguishable from the light-emitting area, and have no obvious side wall effect.

Claims

1. A full-color Micro-LED chip array based on perovskite materials, comprising a plurality of color perovskite Micro-LED chips, each color perovskite Micro-LED chip comprising a functional layer and an electrode, wherein the functional layer comprises a Micro-LED bottom transmission layer, a Micro-LED active layer and a Micro-LED top transmission layer, characterized in that Perovskite Micro-LED active layers of other colors are obtained on the monochrome perovskite Micro-LED active layer by halogen anion exchange method.

2. The full-color Micro-LED chip array based on perovskite material according to claim 1, characterized in that: The halogen anion exchange is to prepare the anion exchange material on the monochrome perovskite Micro-LED active layer by solution method or vapor deposition method, so as to achieve anion exchange; Among them, the anion exchange material in the solution method is composed of one or more materials, and the mass fraction of the anion exchange material is 0.05% to 20%; the preferred mass fraction is 0.1% to 4%; the vapor deposition method is to deposit anion exchange material with a thickness of 1nm-200nm onto the monochrome perovskite Micro-LED active layer to achieve anion exchange.

3. The full-color Micro-LED chip array based on perovskite material according to claim 2, characterized in that: The anion exchange material is one or more of TPPB, PBAB, PBAC, TPPC, HBr, HI, HBr, CH3NH3I, CH3NH3Br, CH3NH3Cl, CH(NH2)2Br, CH(NH2)2I, CH(NH2)2Cl, CsBr, CsI, CsCl, RbBr, RbCl, RbI, or TiCl4, or a nucleophilic substitution reaction raw material halide C2H3Cl3, CH2Cl2, C2H2Cl4, CHI3, CHBr3, CHCl3, C2H4I2, C2H4Br2, C2H4Cl2, C3H7Br, C3H6I2, C3H6Br2, C3H6Cl2, C4H8I2, C4H8Br2, C4H8Cl2, C4H9Br, C5H 10 I2, C5H 10 Br2、C5H 10 Cl2, C6H4Cl2, C6H5Br, C7H7Cl, C7H6ClF, C9H9Cl and nucleophile C9H 21 P.C. 12 H 27 P.C. 24 H 51 P.C. 18 H 15 P, C6H 15 N, C9H 21 N, C 12 H 27 N, C 15 H 33 N reaction mixed solution.

4. The full-color Micro-LED chip array based on perovskite material according to claim 1, characterized in that The chip array was prepared by the following method: S1, preparing a full-color perovskite Micro-LED array pattern on a substrate; S2, preparing the bottom transmission layer on the full-color perovskite Micro-LED array pattern; S3, preparing an arrayed monochrome perovskite Micro-LED active layer on the bottom transmission layer; S4, spin coating photoresist on the arrayed single-color perovskite Micro-LED active layer or using electron beam lithography to expose part of the single-color perovskite Micro-LED active layer; realizing other color perovskite Micro-LED active layers on the exposed part of the single-color perovskite Micro-LED active layer by anion exchange, thereby obtaining an arrayed two-color perovskite Micro-LED active layer; S5. Spin-coating photoresist on the arrayed two-color perovskite Micro-LED active layer or using electron beam lithography to expose a portion of the perovskite Micro-LED active layer; and realizing a third-color perovskite Micro-LED active layer by anion exchange on the exposed portion of the perovskite Micro-LED active layer; S6, exposing the three-color perovskite Micro-LED active layer by debonding, and sequentially preparing the full-color Micro-LED top transmission layer on the three-color perovskite Micro-LED active layer; S7, preparing a metal electrode on the top transport layer; S8, packaging to obtain a full-color Micro-LED chip array.

5. The full-color Micro-LED chip array based on perovskite material according to claim 4, characterized in that: The preparation of the transport layer in S2 comprises the following steps: Spin-coat the transport layer material onto the full-color perovskite Micro-LED array pattern at a speed of 1000 to 8000 rpm and bake on a hot plate; Alternatively, the transport layer material can be deposited onto the full-color perovskite Micro-LED array pattern by evaporation.

6. The full-color Micro-LED chip array based on perovskite material according to claim 4, characterized in that: The preparation of the arrayed monochrome perovskite Micro-LED active layer in S3 includes the following steps: The perovskite precursor solution is dropped onto the bottom Micro-LED transport layer and spin-coated at 1000-8000 rpm, and annealed at 40-200 °C; Alternatively, the perovskite precursor is deposited onto the arrayed bottom Micro-LED transport layer by multi-source co-evaporation to obtain an arrayed monochrome Micro-LED active layer with a thickness of 5-300nm.

7. The full-color Micro-LED chip array based on perovskite material according to claim 1, characterized in that: The perovskite material used in the active layer of the monochrome perovskite Micro-LED chip is A2B N-1 M N X 3N+1 or BMX3, wherein A is a long-chain organic cation, B is a monovalent cation, M is a divalent metal cation, X is any one or more of the halogen elements Cl, Br, I, N is 1, 2, ..., ∞, is the number of layers of the inorganic skeleton of the perovskite material, or is a perovskite derivative Cs4SnBr6, Cs4SnI6, Cs4SnCl6, Cs3Bi2I9, Cs3Sb2I9, Cs3Sb2Br9, Cs3Sb2C l9, one or more of Cs5Cu3Cl6I2, Cs5Cu3Cl7I, CsCu2Cl3, CsCu2I3, CsCu2Br3, Ru2CuBr3, Ru2CuCl3, K2CuBr3, CsCu2I2Cl, CsCu2I2Br, CsCu2Br2I, CsCu2Br2Cl, CsCu2Cl2I, CsCu2Cl2Br, and Cs3Bi2Br9.

8. The full-color Micro-LED chip array based on perovskite material according to claim 1, characterized in that: The transport layer is a Micro-LED electron transport layer or a Micro-LED hole transport layer; the perovskite full-color Micro-LED chip is a formal structure or a trans structure.

9. The full-color Micro-LED chip array based on perovskite material according to claim 8, characterized in that: The Micro-LED electron transport layer is ZnO, SnO2, TmPyPb, TPBi, and the Micro-LED hole transport layer is TFB, TPD, PVK, PEDOT:PSS, PTAA.

10. A method for preparing a full-color Micro-LED chip array based on perovskite material according to claim 1, characterized in that The following steps are involved: S1, preparing a full-color perovskite Micro-LED array pattern on a substrate; S2, preparing the bottom transmission layer on the full-color perovskite Micro-LED array pattern; S3, preparing an arrayed monochrome perovskite Micro-LED active layer on the bottom transmission layer; S4, spin coating photoresist on the arrayed single-color perovskite Micro-LED active layer or using electron beam lithography to expose part of the single-color perovskite Micro-LED active layer; realizing other color perovskite Micro-LED active layers on the exposed part of the single-color perovskite Micro-LED active layer by anion exchange, thereby obtaining an arrayed two-color perovskite Micro-LED active layer; S5. Spin-coating photoresist on the arrayed two-color perovskite Micro-LED active layer or using electron beam lithography to expose a portion of the perovskite Micro-LED active layer; and realizing a third-color perovskite Micro-LED active layer by anion exchange on the exposed portion of the perovskite Micro-LED active layer; S6, exposing the three-color perovskite Micro-LED active layer by debonding, and sequentially preparing the full-color Micro-LED top transmission layer on the three-color perovskite Micro-LED active layer; S7, preparing a metal electrode on the top transport layer; S8, packaging to obtain a full-color Micro-LED chip array.

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