Organic light emitting field effect transistor and preparation method and application thereof

Abstract

The application discloses an organic light-emitting field effect transistor and a preparation method and application thereof, and the organic light-emitting field effect transistor comprises a reflective grating electrode, a semi-transparent drain electrode and a source electrode. The organic light-emitting field effect transistor with the microcavity effect constructed by the reflective grating electrode and the semi-transparent drain electrode can realize the spectral narrowing of red, green and blue light-emitting materials under the effect of the microcavity enhancement.

Description

Technical Field

[0001] This invention belongs to the field of electroluminescent devices, specifically relating to an organic light-emitting field-effect transistor, its fabrication method, and its application. Background Technology

[0002] Narrow-spectrum, wide-gamut electroluminescence plays a crucial role in high-quality displays, optical communications, and phototherapy, and is essential for more realistic images, higher-capacity data transmission, and specialized medical applications. Currently developed multi-resonance thermally activated delayed fluorescence materials exhibit narrow fluorescence emission due to the opposing resonance effect generated by the rigid polycyclic aromatic skeleton structure between boron and nitrogen atoms. In such molecules, the structural relaxation of the excited state can be effectively reduced, resulting in full width at half maximum (FWHM) values ​​mostly in the 20-40 nm range. However, further reducing the FWHM remains quite challenging from a materials design and synthesis perspective. On the other hand, researchers often introduce microcavity structures or distributed Bragg reflector (DBR) structures into devices to achieve narrow-spectrum emission. While these efforts have yielded significant results, specific optical structures need to be designed for different luminescent materials, involving complex device fabrication and incurring considerable costs. Developing an electroluminescent device with intrinsic narrowing capabilities is fundamental and crucial for advancing applications in related fields.

[0003] Organic light-emitting field-effect transistors (OLETs) are a unique type of optoelectronic integrated device that combines the functions of both field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs), offering significant advantages in simplifying integrated circuits. Their unique three-terminal device structure gives OLETs a clear advantage in simplifying device integration and reducing power consumption, making them highly promising for smart displays, optical communications, and visual intelligent sensing. Existing planar OLET device structures exhibit high aperture ratios (up to 80%) and surface-emitting characteristics. Furthermore, because the device cavity length is the sum of the two units in an OFET and an OLED, the microcavity effect allows for narrowing of the intrinsic spectrum and improved efficiency. However, existing OLEDs still have relatively wide emission spectral ranges and are complex to manufacture, resulting in higher costs. Summary of the Invention

[0004] Currently developed narrow-spectrum light-emitting materials have a minimum free-wavelength (FWHM) of 20–40 nm. Introducing a drain-beam (DBR) structure into organic light-emitting field-effect transistor (OLED) devices can further narrow the spectrum. However, different light-emitting materials require specific optical structures, leading to increased process complexity and cost. Based on this, this invention proposes an OLED. The inventors discovered that an OLED with a microcavity effect, constructed using a reflective grating electrode and a semi-transparent drain electrode, can achieve spectral narrowing for red, green, and blue light-emitting materials through microcavity enhancement. Furthermore, due to the flexibility of organic semiconductors, integration with wearable devices is possible, which is more advantageous for expanding the functionality and application scenarios of wearable surface light source devices.

[0005] The technical solution of the present invention is as follows:

[0006] An organic light-emitting field-effect transistor includes a reflective grid electrode, a semi-transparent drain electrode, and a source electrode.

[0007] According to an embodiment of the present invention, both the semi-transparent drain electrode and the source electrode are disposed on the reflective grating electrode.

[0008] According to an embodiment of the present invention, a dielectric layer, a semiconductor charge transport layer, and a light-emitting unit are sequentially disposed between the reflector electrode and the semi-transparent drain electrode. Alternatively, a dielectric layer and a semiconductor charge transport layer are sequentially disposed between the reflector electrode and the source electrode.

[0009] According to an embodiment of the present invention, an antireflection layer is further disposed on the semi-transparent drain electrode.

[0010] According to an embodiment of the present invention, the half-width at half-maximum (FWHM) of the spectrum emitted by the transistor is less than or equal to 40 nm, or the electroluminescence spectrum of the transistor is narrower than the photoluminescence spectrum of the light-emitting unit itself by 20% to 85%.

[0011] For example, the full width at half maximum (FWHM) of the emission spectrum of a transistor can be 0.5nm, 1nm, 2nm, 4nm, 6nm, 8nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 24nm, 26nm, 28nm, 30nm, 32nm, 34nm, 36nm, 38nm, or 39nm.

[0012] Preferably, the organic light-emitting field-effect transistor includes:

[0013] Support substrate;

[0014] Reflective grating electrodes are disposed on the surface of the supporting substrate;

[0015] A dielectric layer disposed on the reflector electrode;

[0016] A semiconductor charge transport layer disposed on the dielectric layer;

[0017] A source electrode and a light-emitting unit disposed on the semiconductor charge transport layer; preferably, the source electrode and the light-emitting unit are disposed on different sides of the semiconductor charge transport layer.

[0018] A semi-transparent drain electrode is disposed above the light-emitting unit;

[0019] An antireflective layer disposed on the semi-transparent drain electrode.

[0020] It should be noted that when a component such as a layer, film, crystal, region, or substrate is referred to as being disposed "above" / "below" or "between two components", it can be placed directly above / below another component, or directly between two components, or one or more intermediate layers may exist.

[0021] According to an embodiment of the present invention, the source electrode and the semi-transparent drain electrode are arranged in a non-planar manner, and the light-emitting portion is the entire effective area of ​​the source electrode or the semi-transparent drain electrode. Preferably, the reflector voltage is adjustable to control the light emission brightness.

[0022] According to an embodiment of the present invention, the supporting substrate is a rigid substrate (e.g., silicon dioxide, glass, or quartz) or a flexible substrate (e.g., polycarbonate (PC), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), etc.).

[0023] According to an embodiment of the present invention, the reflective grating electrode can be a single-layer or multi-layer structure, having good reflective properties in the visible spectrum wavelength range (390nm~780nm), for example, a reflectivity of 10%~100%, preferably 60-100%, even more preferably 80-100%, more preferably 90-100%, and even more than 95%.

[0024] Preferably, the reflector electrode is a layer formed from one or more of Si, Ag, and indium tin oxide (ITO), and more preferably an ITO / Ag / ITO layer.

[0025] According to embodiments of the present invention, there is no particular limitation on the type of dielectric layer, which can be an inorganic material dielectric layer and / or an organic material dielectric layer. Exemplarily, the dielectric layer is an inorganic material dielectric layer, such as a dielectric layer formed of inorganic oxides (Al2O3, SiO2); and / or, the dielectric layer is an organic material dielectric layer, such as a polyvinyl alcohol / organic fluoropolymer CYTOP bilayer dielectric layer or a polymethyl methacrylate (PMMA) monolayer dielectric layer.

[0026] According to an embodiment of the present invention, the dielectric layer can be prepared by a method known in the art. For example, at least one of thermal growth, physical vapor deposition, spin coating, etc., can be selected.

[0027] According to embodiments of the present invention, there is no particular limitation on the thickness of the dielectric layer. Exemplarily, the thickness of the dielectric layer is 10-800 nm. Those skilled in the art can adjust the thickness of the dielectric layer according to actual needs.

[0028] According to an embodiment of the present invention, the mobility of the semiconductor charge transport layer is not less than 0.1 cm. 2 V -1 s -1 The material in the semiconductor charge transport layer has excellent electrical properties.

[0029] For example, the semiconductor charge transport layer includes organic semiconductor materials and / or inorganic semiconductor materials, such as organic semiconductor materials selected from small molecule materials and / or polymer materials.

[0030] Preferably, the organic semiconductor material is selected from one or more of the following substances, including but not limited to: 2,7-dioctyl[1]benzothiophene[3,2-b]benzothiophene (C8-BTBT), 2,6-diphenylanthracene (DPA), 2,6-dinaphthylanthracene (dNaAnt), 2,6-bis(p-hexylbenzene)anthracene (C6-DPA), 2,6-bis(p-octylhexylbenzene)anthracene (C8-DPA), 2,6-bis(p-decylbenzene)anthracene (C10-DPA), poly(3-hexylthiophene) (P3HT), 9,9-dioctylfluorene-benzothiadiazole copolymer (F8BT), poly[2,5-(2-octyldodecyl)-3,6-dionepyrrolopyrrole-alt-5,5-(2,5-bis(thiophene-2-yl)thiophene[3,2-b]thiophene)] (DPP-DTT), more preferably C8-BTBT.

[0031] Preferably, the inorganic semiconductor material is selected from one or more of the following substances, including but not limited to: carbon nanotubes (CNTs), zinc tin oxide (ZTO), gallium nitride (GaN), silicon carbide (SiC), and zinc selenide (ZnSe).

[0032] According to an embodiment of the present invention, the light-emitting unit includes a light-emitting layer and an electron transport layer, a hole transport layer, an electron injection layer, and / or a hole injection layer that match the energy level of the light-emitting layer.

[0033] Furthermore, the light-emitting layer may be a layer formed of a light-emitting material with a light-emitting mechanism known in the art, for example, the light-emitting material may be selected from one or more of fluorescent materials, phosphorescent materials and thermally active delayed fluorescence materials.

[0034] Preferably, the fluorescent material is selected from one or more of rubrene, aluminum octahydroxyquinoline (Alq3), 5,6,11,12-tetraphenyltetraphenyl (Rubrene), and 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAVBi).

[0035] Preferably, the phosphorescent material is selected from one or more of the following: bis(1-phenyl-isoquinoline)(acetylacetone)iridium(III) (Ir(piq)2acac), bis(2,3-diphenylquinoxaloline)iridium(Ir(mphmq)2tmd), tris(2-phenylpyridine)iridium(Ir(ppy)3), bis(2-phenylpyridine-C2,N)iridium(Ir(ppy)2(acac)), and iridium(III)tris[N,N'-diphenylbenzimidazole-2-ylidene-C2,C2'] (Ir(dpbic)3).

[0036] Preferably, the thermally active delayed fluorescence material is selected from one or two of the following: tert-butyl-2,12-bis(4-tert-butylphenyl)-5,9-dihydro-5,9-diaza-13b-boronnaphthalene[3,2,1-de]anthracene (t-DABNA), dihydroacenaphthene-nitrogen heterocyclic compound (tCzphB-Fl), 10-(4-(4,6-diphenyl-1,3,5-triazol-2-yl)phenyl)-9,9-dimethyl-9,10-dihydroacridine (DMAC-TRZ), 9,9'-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)-1,3-phenylene)bis(9Hcarbazole) (DCzTRZ), and (N-phenoxazine)phenyl]sulfone (PXZ-DPS).

[0037] Furthermore, the light emitted by the light-emitting unit has a spectrum between 390nm and 780nm.

[0038] For example, the light-emitting layer in the light-emitting unit can be formed of a single light-emitting material or it can be formed by a guest material doped with a host material. In this invention, the term "doping" refers to doping a guest material into a host material, wherein the mass of the guest material is less than 30 wt% of the host material, and the guest material and the host material are different.

[0039] According to an embodiment of the present invention, the single luminescent material is preferably Alq3, DPA, or dNaAnt; the guest dopant in the guest dopant host material can be one or more substances, and the host material can be a single substance or a mixture.

[0040] For example, preferred guest dopants include t-DABNA, tCzphB-Fl, 1,4-bis(10-phenylanthracene-9-yl)benzene (BD1), BDAVBi, perylene, bis(dimethyl-dihydroacrylidinephenylsulfone) (DMAC-DPS), bis[2-(5-cyano-4,6-difluorophenyl)pyridine-C2,N)]pyridinecarboxylic iridium (FCNirPic), and iridium(III)bis[(2,3,4-difluorophenyl)-pyridine-N,C2']pyridinecarboxylate (Ir(tfpd) )2pic), Ir(mphmq)2tmd, 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), 9,9'-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)-1,3-phenyl)bis(9H-carbazole) (DCzTrz), 5,5-dibromo-4,4-tetracosyl-2,2-bithiophene (fac-Ir(dpbic)3), Ir(ppy)3, tris[2-(p-tolyl)pyridine]iridium(III) (Ir(mppy)3) Ir(ppy)2acac, bis(2-(naphthyl-2-yl)pyridine)(acetylacetone)iridium(III)(Ir(npy)2acac), tris[2-(3-methyl-2-pyridyl)phenyl]iridium(Ir(3mppy)3), bis(2-(3,5-dimethylphenyl)quinoline-C2,N')(acetylacetone)iridium(III)(Ir(dmpq)2acac), bis(2-(2'-benzothiophene)-pyridine-N,C3')iridium(acetylacetone)(Ir(btp)2(acac)) One or more of the following: 4-(dicyanomethylene)-2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazine-9-yl)vinyl]-4H-pyran (DCM2), 5,6,11,12-tetraphenylbenzotetraphenyl (Rubrene), tris(2-(3,5-dimethylphenyl)quinoline-C2,N')iridium(III) (Ir(dmpq)3), and 2,8-di-tert-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenylbenzotetraphenyl (TBRb);

[0041] For example, preferred host materials include 3,3′-bis(9H-carbazole-9-yl)biphenyl (mCBP), 9,9′-(1,3-phenyl)bis-9H-carbazole (mCP), bis[2-((oxo)diphenylphosphino)phenyl] ether (DPEPO), 4,4′-bis(N-carbazole)-1,1′-biphenyl (CBP), 4,4′-bis(2,2-diphenyl-vinyl-1-yl)-4,4′-dimethylphenyl (p-DMDPVBi), 4,4′-bis(2,2-stilbeneyl)-1,1′-biphenyl (DPVBi), 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (TBADN), diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (TSPO1), and 3-(3-(9H-carbazole-9-yl)phenyl)benzofuran[2,3-b]pyridine (P Cz-BFP), 2,4,6-tris[3-(diphenylphospho)phenyl]-1,3,5-triazole (PO-T2T), 2,4,6-tris(3-(carbazole-9-yl)phenyl)-1,3,5-triazine (TCPZ), 4,4'-bis(triphenylsilyl)-1,1'-biphenyl (BSB), 2,7-bis[9,9-di(4-methylphenyl)fluorene-2-yl]-9,9 One or more of the following: bis(4-methylphenyl)fluorene (TDAF), 3',3”,3”'-(1,3,5-triazine-2,4,6-triyl)tris(([1,1'-biphenyl]-3-nitrile))(CN-T2T), and 10-(4-(4,6-diphenyl-1,3,5-triazol-2-yl)phenyl)-9,9-dimethyl-9,10-dihydroacridine (DMAC-TRZ).

[0042] Preferably, the light-emitting unit is a green light-emitting unit 1,1-bis[4-[N,N-di(p-tolyl)amino]phenyl]cyclohexane (TAPC) / 7,7,8,8-tetrasubstituted spiroxazino[1,3]oxazin-2-tetracarboxylic acid (TcTa) / 10%Ir(ppy)2acac:mCP / TmPyPB, or TAPC / TcTa / 3%tCzphB-Fl:mCBP / TmPyPB.

[0043] Preferably, the light-emitting unit is a red light-emitting unit TAPC / TcTa / 10% Ir(piq)2acac:mCP / TmPyPB or TAPC / TcTa / 8% Ir(mphmq)2tmd:CBP / TmPyPB.

[0044] Preferably, the light-emitting unit is a blue light-emitting unit TAPC / mCBP / 3%t-DABNA:mCBP / TmPyPB, TAPC / TcTa / 10% DMAC-DPS:DPEPO / TmPyPB, or TAPC / TcTa / 10%rubrene:CBP / TmPyPB.

[0045] For example, the light-emitting unit is 140nm TAPC / 10nm TcTa / 25nm 10%Ir(ppy)2acac:mCP / 45nm TmPyPB, 70nm TAPC / 10nm TcTa / 30nm 10%Ir(piq)2acac:mCP / 40nm TmPyPB or 50nm TAPC / 10nm mCBP / 30nm 3%t-DABNA / 30nm TmPyPB.

[0046] According to embodiments of the present invention, the semiconductor charge transport layer and the light-emitting unit can be fabricated using methods known in the art, including but not limited to vacuum thermal evaporation, physical vapor transport, solution shearing, solution epitaxy, spin coating, and inkjet printing. Those skilled in the art will understand that the specific method used can be selected based on the physical properties (e.g., solubility, melting and boiling points) of the actual semiconductor material used.

[0047] For example, the method for preparing the active layer, including the semiconductor charge transport layer and the light-emitting unit, can be selected from any of the following methods:

[0048] Method 1: In the vapor deposition chamber, a thin film of the small molecule material is deposited on the dielectric layer and electrode by vacuum evaporation deposition to obtain the active layer;

[0049] Method 2: A solution of the active layer material is spin-coated onto the dielectric layer and electrodes to obtain the active layer;

[0050] Method 3: Preparation and growth of single-crystal thin films of the small molecule material by solution epitaxy: The small molecule material is dissolved in a solvent that is immiscible with water, and the resulting homogeneous solution is slowly added dropwise to the surface of water. The mixed solution spreads on the surface of the water, and the solvent evaporates to obtain the single-crystal thin film. A supporting substrate with a dielectric layer is inserted into the water to transfer the single-crystal thin film to the surface of the dielectric layer to obtain the active layer.

[0051] Method 4: Preparation of single-crystal thin films of the small molecule material by solution shearing: The small molecule material is dissolved in an organic solvent, and the resulting uniformly mixed solution is dropped onto a support substrate with a dielectric layer. The dropped solution is then slowly sheared and stretched to form an active layer.

[0052] Charge is injected from one end of the semiconductor charge transport layer (taking the source electrode as an example), and transported to the other end in an extremely thin channel formed under the applied gate voltage. A relatively uniform current injection is formed below the other electrode (taking the semi-transparent drain electrode as an example), and recombines with the electrons injected by the semi-transparent drain electrode to form a uniform surface light source emission.

[0053] According to an embodiment of the present invention, the thickness of the semiconductor charge transport layer and the light-emitting unit are both in the nanometer to submicrometer range. For example, the thickness of each layer can be independently 5-500 nm, preferably 40-300 nm, so that the electroluminescence spectrum of the transistor as defined above can be narrowed by 20% to 85% compared with the photoluminescence spectrum of the light-emitting unit itself.

[0054] According to an embodiment of the present invention, the semi-transparent drain electrode can be a single-layer or multi-layer structure, possessing good light transmittance characteristics within the visible spectrum wavelength range (390nm~780nm). Preferably, the transmittance of the semi-transparent drain electrode to visible light is 20%-90%, more preferably 20%-60%, even more preferably 30%-50%, and more preferably 40%-50%.

[0055] Preferably, the semi-transparent drain electrode is selected from layers formed by one or more of Al, Mg, Ag, ITO and LiF, and is more preferably a layer formed by an alloy of Mg and Ag.

[0056] According to embodiments of the present invention, the source electrode can be a transparent electrode or an opaque electrode, and is independently selected from any one or more of the following substances, including but not limited to: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, nickel, gold, molybdenum, iron, and lead; alloys of the aforementioned metals; multilayer materials, such as LiF / Al, LiO2 / Al, or LiF / Al / Ag; and metal oxides, such as ITO, IZO, and MoO. x And so on. Those skilled in the art will understand that the specific type of metal selected can be adjusted according to the energy band of the semiconductor material.

[0057] According to an embodiment of the present invention, the source electrode, the semi-transparent drain electrode, and the reflective grating electrode are prepared by methods known in the art. For example, at least one of vacuum thermal evaporation, inkjet printing, and electron beam deposition methods can be selected.

[0058] According to an embodiment of the present invention, the material of the antireflection layer is selected from NPB; preferably, the thickness of the antireflection layer is 50-100 nm, for example, 80-100 nm.

[0059] According to an embodiment of the present invention, the organic light-emitting field-effect transistor can emit planar light that matches the color of the light-emitting unit under an applied voltage.

[0060] The present invention also provides a method for fabricating the above-mentioned organic light-emitting field-effect transistor, comprising the following steps: setting a reflective grating electrode below a semi-transparent drain electrode or source electrode;

[0061] The semi-transparent drain electrode, source electrode, and reflector electrode have the meanings described above.

[0062] According to an embodiment of the present invention, the fabrication method includes: sequentially disposing a dielectric layer, a semiconductor charge transport layer, and a light-emitting unit between a reflective grating electrode and a semi-transparent drain electrode;

[0063] The semiconductor charge transport layer, light-emitting unit, and dielectric layer all have the meanings described above.

[0064] According to an embodiment of the present invention, the preparation method includes: further providing an antireflection layer on the semi-transparent drain electrode.

[0065] The present invention also provides the application of the above-described organic light-emitting field-effect transistor in wearable devices.

[0066] This invention also provides applications of the above-described organic light-emitting field-effect transistor in lighting, laser display, electrically pumped laser, or other related applications. For example, these other related applications include lasers.

[0067] The beneficial effects of this invention are:

[0068] 1. The narrow-spectrum organic light-emitting field-effect transistor device of the present invention can purify the spectrum of red, green and blue light-emitting materials, improve color purity, and help the device to be used in the field of wide color gamut display.

[0069] 2. The narrow-spectrum organic light-emitting field-effect transistor device described in this invention can achieve good compatibility with flexible wearable devices, and plays an important role in promoting the development of light-emitting field-effect transistor devices.

[0070] 3. This invention develops narrow-spectrum organic light-emitting field-effect transistor devices based on organic semiconductors, which can make the most of the advantages of abundant, lightweight, inexpensive and easy-to-process organic semiconductor materials, and provides an effective solution for the large-area controllable and arrayed fabrication of light-emitting field-effect transistor devices.

[0071] 4. The present invention employs an organic light-emitting field-effect transistor with microcavity effect constructed using a reflective grating electrode and a semi-transparent drain electrode. Under the effect of microcavity enhancement, the spectrum of red, green and blue light-emitting materials can be narrowed. Attached Figure Description

[0072] Figure 1 A schematic diagram of an organic light-emitting field-effect transistor device that emits light from a surface source.

[0073] Figure 2 The electroluminescence spectra of the narrow-spectrum organic light-emitting field-effect transistor devices with blue, green, and red primary colors prepared in Examples 1, 2, and 3, and the photoluminescence spectra of the materials in dilute solutions are shown.

[0074] Figure 3 Blue light index-brightness, current efficiency-brightness, and current efficiency-brightness curves of the narrow-spectrum organic light-emitting field-effect transistor devices with blue, green, and red primary colors prepared in Examples 1, 2, and 3. Detailed Implementation

[0075] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0076] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0077] Example 1

[0078] Narrow-spectrum organic light-emitting field-effect transistor devices based on t-DABNA:mCBP blue light-emitting units

[0079] 1) Cleaning and dielectric layer preparation of glass / 8nm ITO / 100nm Ag / 8nm ITO substrates:

[0080] A glass / 8nm ITO / 100nm Ag / 8nm ITO substrate (with a visible light reflectance greater than 95%) was sequentially sonicated with deionized water, acetone, and isopropanol for approximately 10 minutes each, and then rapidly dried using nitrogen. The surface energy levels were modified for 5 minutes in an O2 plasma cleaner to remove residual organic solvents. In a nitrogen-atmosphere glove box, a polyvinyl alcohol aqueous solution (80 mg / mL, 4200 rpm, 45 seconds) was spin-coated and heated to 100°C for 90 minutes. After natural cooling, a dilute CYTOP solution was spin-coated (5000 rpm, 60 seconds) and heated to 100°C for 90 minutes, followed by natural cooling.

[0081] 2) Fabrication of the C8-BTBT semiconductor charge transport layer

[0082] The patterned metal mask is fixed to the substrate, and C8-BTBT with a thickness of 50 nm is thermally evaporated on the dielectric layer of step 1) using a vacuum coating machine at an evaporation rate of 0.03 nm / s.

[0083] 3) Fabrication of the source electrode

[0084] After replacing the mask and fixing it to the substrate, 2nm of MoO3 and 40nm of Au are thermally evaporated on one side of the semiconductor charge transport layer using a vacuum coating machine.

[0085] 4) Fabrication of the light-emitting unit:

[0086] After replacing the mask and fixing it to the substrate, 50nm TAPC / 10nm mCBP / 30nm 2% t-DABNA:mCBP / 30nm TmPyPB are sequentially deposited on the other side of the semiconductor charge transport layer using a vacuum deposition machine.

[0087] 5) Fabrication of the semi-transparent drain electrode and antireflection layer:

[0088] After replacing the mask and fixing it to the substrate, a 1nm LiF / 12nm magnesium-silver alloy was sequentially deposited on the light-emitting unit using a vacuum deposition machine as a semi-transparent drain electrode (with a transmittance of 40-50% for visible light), and an 80nm NPB was deposited as an anti-reflection layer. The fabrication of the device was then completed.

[0089] 6) Performance testing and characterization of light-emitting field-effect transistors:

[0090] In a nitrogen atmosphere within a glove box, voltages were applied to the source, drain, and gate electrodes using probes. The gate electrode was a layer formed of ITO / Ag / ITO, the source electrode was grounded, and the voltage between the source and drain electrodes was -25V. The voltage between the gate and source electrodes varied from 0V to -25V in steps of -0.5V. In a dark environment, the photocurrent of the device was measured using a photomultiplier tube at the 0.7V setting, and the current-photocurrent-voltage relationship curve was measured. The device spectrum was measured using a spectrometer, and emission images were acquired using a CCD.

[0091] Example 2

[0092] Narrow-spectrum organic light-emitting field-effect transistor devices based on Ir(ppy)2acac:mCP green light-emitting units

[0093] 1) Cleaning and dielectric layer preparation of glass / 8nm ITO / 100nm Ag / 8nm ITO substrates:

[0094] A glass / 8nm ITO / 100nm Ag / 8nm ITO substrate (with a visible light reflectance greater than 95%) was sequentially sonicated with deionized water, acetone, and isopropanol for approximately 10 minutes each, and then rapidly dried using nitrogen. The surface energy levels were modified for 5 minutes in an O2 plasma cleaner to remove residual organic solvents. In a nitrogen-atmosphere glove box, a polyvinyl alcohol aqueous solution (80 mg / mL, 4200 rpm, 45 seconds) was spin-coated and heated to 100°C for 90 minutes. After natural cooling, a dilute CYTOP solution was spin-coated (5000 rpm, 60 seconds) and heated to 100°C for 90 minutes, followed by natural cooling.

[0095] 2) Fabrication of C8-BTBT organic semiconductor charge transport layer

[0096] The patterned metal mask is fixed to the substrate, and C8-BTBT with a thickness of 50 nm is thermally evaporated on the dielectric layer of step 1) using a vacuum coating machine at an evaporation rate of 0.03 nm / s.

[0097] 3) Fabrication of the source electrode

[0098] After replacing the mask and fixing it to the substrate, 2nm of MoO3 and 40nm of Au are thermally evaporated on one side of the semiconductor charge transport layer using a vacuum coating machine.

[0099] 4) Fabrication of the light-emitting unit:

[0100] After replacing the mask and fixing it to the substrate, 140nm TAPC / 10nm TcTa / 25nm 10% Ir(ppy)2acac:mCP / 45nm TmPyPB are sequentially deposited on the other side of the semiconductor charge transport layer using a vacuum deposition machine.

[0101] 5) Fabrication of the semi-transparent drain electrode and antireflection layer:

[0102] After replacing the mask and fixing it to the substrate, a 1nm LiF / 12nm magnesium-silver alloy was sequentially deposited on it using a vacuum deposition machine as a semi-transparent drain electrode (with a visible light transmittance of 40-50%), and an 80nm NPB was deposited as an anti-reflection layer. The device fabrication was then complete.

[0103] 6) Performance testing and characterization of light-emitting field-effect transistors:

[0104] In a nitrogen atmosphere within a glove box, voltages were applied to the source, drain, and gate electrodes using probes. The gate electrode was a layer formed of ITO / Ag / ITO, the source electrode was grounded, and the voltage between the source and drain electrodes was -25V. The voltage between the gate and source electrodes varied from 0V to -25V in steps of -0.5V. In a dark environment, the photocurrent of the device was measured using a photomultiplier tube at the 0.7V setting, and the current-photocurrent-voltage relationship curve was measured. The device spectrum was measured using a spectrometer, and emission images were acquired using a CCD.

[0105] Example 3

[0106] Narrow-spectrum organic light-emitting field-effect transistor devices based on Ir(piq)2acac:mCP red light-emitting units

[0107] 1) Cleaning and dielectric layer preparation of glass / 8nm ITO / 100nm Ag / 8nm ITO substrates:

[0108] A glass / 8nm ITO / 100nm Ag / 8nm ITO substrate (with a visible light reflectance greater than 95%) was sequentially sonicated with deionized water, acetone, and isopropanol for approximately 10 minutes each, and then rapidly dried using nitrogen. The surface energy levels were modified for 5 minutes in an O2 plasma cleaner to remove residual organic solvents. In a nitrogen-atmosphere glove box, a polyvinyl alcohol aqueous solution (80 mg / mL, 4200 rpm, 45 seconds) was spin-coated and heated to 100°C for 90 minutes. After natural cooling, a dilute CYTOP solution was spin-coated (5000 rpm, 60 seconds) and heated to 100°C for 90 minutes, followed by natural cooling.

[0109] 2) Fabrication of C8-BTBT organic semiconductor charge transport layer

[0110] The patterned metal mask is fixed to the substrate, and C8-BTBT with a thickness of 50 nm is thermally evaporated on the dielectric layer of step 1) using a vacuum coating machine at an evaporation rate of 0.03 nm / s.

[0111] 3) Fabrication of the source electrode

[0112] After replacing the mask and fixing it to the substrate, 2nm of MoO3 and 40nm of Au are thermally evaporated on one side of the semiconductor charge transport layer using a vacuum coating machine.

[0113] 4) Fabrication of the light-emitting unit:

[0114] After replacing the mask and fixing it to the substrate, 70nm TAPC / 10nm TcTa / 30nm 10% Ir(piq)2acac:mCP / 40nm TmPyPB are sequentially deposited on the other side of the semiconductor charge transport layer using a vacuum deposition machine.

[0115] 5) Fabrication of the semi-transparent drain electrode and antireflection layer:

[0116] After replacing the mask and fixing it to the substrate, a 1nm LiF / 12nm magnesium-silver alloy was sequentially deposited on it using a vacuum deposition machine as a semi-transparent drain electrode (with a visible light transmittance of 40-50%), and an 80nm NPB was deposited as an anti-reflection layer. The device fabrication was then complete.

[0117] 6) Performance testing and characterization of light-emitting field-effect transistors:

[0118] In a nitrogen atmosphere within a glove box, voltages were applied to the source, drain, and gate electrodes using probes. The gate electrode was a layer formed of ITO / Ag / ITO, the source electrode was grounded, and the voltage between the source and drain electrodes was -25V. The voltage between the gate and source electrodes varied from 0V to -25V in steps of -0.5V. In a dark environment, the photocurrent of the device was measured using a photomultiplier tube at the 0.7V setting, and the current-photocurrent-voltage relationship curve was measured. The device spectrum was measured using a spectrometer, and emission images were acquired using a CCD.

[0119] Figure 1 This is a schematic diagram of a narrow-spectrum organic light-emitting field-effect transistor device.

[0120] Figure 2 The electroluminescence spectra of the narrow-spectrum organic light-emitting field-effect transistor devices with blue, green, and red primary colors prepared in Examples 1, 2, and 3 are compared with the photoluminescence spectra of the materials in dilute solutions. From left to right, the emission colors are blue, green, and red. The FWHM of the electroluminescence spectra in the devices are 13 nm, 16 nm, and 19 nm, respectively, which represent narrowing of the photoluminescence spectra by 41%, 68%, and 65%, respectively.

[0121] Figure 3 The blue light index-luminance (i.e., the light intensity of the narrow-spectrum organic light-emitting field-effect transistor devices with blue, green, and red primary colors prepared in Examples 1, 2, and 3) Figure 3 Left), Current efficiency - brightness (i.e.) Figure 3 (in the middle), current efficiency-brightness curve (i.e.) Figure 3 (Right). For blue, green, and red light-emitting field-effect transistor devices, the maximum blue light index, current efficiency, and current efficiency are 42.4, 15.7 candela / ampere, and 20 candela / ampere, respectively.

[0122] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An organic light-emitting field-effect transistor, characterized in that, It includes a reflective grating electrode, a semi-transparent drain electrode, and a source electrode.

2. The organic light-emitting field-effect transistor according to claim 1, characterized in that, Both the semi-transparent drain electrode and the source electrode are disposed on the reflective grating electrode. Preferably, a dielectric layer, a semiconductor charge transport layer, and a light-emitting unit are sequentially disposed between the reflective grating electrode and the semi-transparent drain electrode. Preferably, an anti-reflection layer is further provided on the semi-transparent drain electrode.

3. The organic light-emitting field-effect transistor according to claim 1, characterized in that, The half-width at half-maximum (WHM) of the spectrum emitted by the transistor is less than or equal to 40 nm, or the electroluminescence spectrum of the transistor is narrower than the photoluminescence spectrum of the light-emitting unit itself by 20% to 85%.

4. The organic light-emitting field-effect transistor according to claim 1, characterized in that, The organic light-emitting field-effect transistor includes: Support substrate; Reflective grating electrodes are disposed on the surface of the supporting substrate; A dielectric layer disposed on the reflector electrode; A semiconductor charge transport layer disposed on the dielectric layer; A source electrode and a light-emitting unit disposed on the semiconductor charge transport layer; preferably, the source electrode and the light-emitting unit are disposed on different sides of the semiconductor charge transport layer. A semi-transparent drain electrode is disposed above the light-emitting unit; An antireflective layer disposed on the semi-transparent drain electrode.

5. The organic light-emitting field-effect transistor according to claim 1, characterized in that, The reflective grating electrode can be a single-layer or multi-layer structure, and has good reflective properties in the visible spectrum wavelength range (390nm~780nm), for example, a reflectivity of 10%~100%. Preferably, the reflector electrode is selected from one or more layers formed from Si, Ag, and indium tin oxide (ITO).

6. The organic light-emitting field-effect transistor according to claim 1, characterized in that, The semi-transparent drain electrode can be a single-layer or multi-layer structure, possessing good light transmittance characteristics within the visible spectrum wavelength range (390nm~780nm). Preferably, the transmittance of the semi-transparent drain electrode to visible light is 20%-90%. Preferably, the semi-transparent drain electrode is selected from layers formed from one or more of Al, Mg, Ag, ITO, and LiF. Preferably, the antireflective layer is made of NPB material.

7. The method for fabricating the organic light-emitting field-effect transistor according to any one of claims 1-6, characterized in that, The process includes the following steps: placing a reflective grating electrode below the semi-transparent drain electrode or source electrode.

8. The method according to claim 7, characterized in that, The fabrication method includes: sequentially disposing a dielectric layer, a semiconductor charge transport layer, and a light-emitting unit between a reflective grating electrode and a semi-transparent drain electrode.

9. The method according to claim 7, characterized in that, The preparation method includes: an antireflection layer is further disposed on the semi-transparent drain electrode.

10. The application of the organic light-emitting field-effect transistor as described in any one of claims 1-6 in wearable devices, lighting, laser display, electrically pumped lasers, or other related application fields.

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