Patent Application
20240006857
This application claims foreign priority of Chinese Patent Application No. 202210786811.3, filed on Jul. 4, 2022 in the China National Intellectual Property Administration, the disclosures of all of which are hereby incorporated by reference.
The present invention relates to the field of optoelectronic materials and technologies, and particularly to an external-cavity-free low-threshold perovskite laser device and an application thereof.
Perovskite material is a novel semiconductor material with excellent optical properties, and has the advantages of large-area solution method preparation, a long carrier migration distance, a low defect state density, a narrow luminescence bandwidth, high photoluminescence quantum yield and a continuously adjustable optical band gap. In recent years, a photovoltaic device and a light-emitting device based on the perovskite material have developed rapidly, wherein power conversion efficiency of a perovskite solar cell has been improved from 4% to 25%, and external quantum efficiency of a perovskite light-emitting diode has been rapidly improved from 0.1% to more than 20% at present. Moreover, the high absorption coefficient, low defect density and high gain value of the perovskite material are comparable to classical semiconductor laser materials such as gallium arsenide. Moreover, the perovskite material shows a lower preparation cost, a simpler preparation method and a better mechanical flexibility of an organic material. The perovskite material shows a higher optical gain than an organic semiconductor gain medium material, thus being beneficial for realizing a high-performance semiconductor laser device. Most importantly, a band gap and an emission wavelength of the perovskite material may realize continuous broadband tuning from ultraviolet to near infrared by controlling a stoichiometric ratio of halogen in a solution or an ion exchange mode after synthesis. Therefore, the perovskite material may effectively make up for a “green gap” in a green optical band between a III nitride material and a V phosphide material used in a traditional inorganic semiconductor laser device. The perovskite material may be prepared by a low-cost solution method, which may solve the problem of high cost caused by traditional preparation methods such as metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) of the III-V materials, thus having great application prospects. At present, the laser device generally comprises three basic elements of a pumping source, a gain medium and a resonant cavity, wherein a resonant effect of the resonant cavity is essential in generation of laser. At present, in a perovskite laser device of optical pumping, the high-quality resonant cavity is mostly realized by complex process design and preparation. The resonant cavity is complicated in machining, long in working hour and high in cost, and a high-temperature preparation environment is involved and a rigid material is used during machining, so that it is difficult to combine with a flexible substrate tolerating a high temperature, thus further limiting an application of a flexible optoelectronic device. At present, researchers have found that lasing of random laser of the perovskite may be generated on the flexible laser substrate by the solution method, but formation of the random laser depends on scattering with a large loss, thus having the disadvantages of a high threshold and a high energy consumption. Therefore, it is urgent to realize a low-threshold perovskite laser device with simple preparation, a low threshold and a low loss, so as to realize an application thereof in many fields.
The technical problem to be solved by the present invention is to provide an external-cavity-free low-threshold perovskite laser device and an application thereof aiming at the defects in the prior art. According to the present invention, the external-cavity-free low-threshold perovskite laser device is prepared on a rigid substrate and a flexible substrate by a preparation method with the characteristics of low-temperature preparation, and may be combined with the flexible substrate difficult to tolerate a high temperature, thus realizing an application of the laser device in the field of flexible optoelectronic devices.
An external-cavity-free low-threshold perovskite laser device consists of a gain medium composed of a perovskite material or a mixed material containing the perovskite material, and one or more of a substrate, an electrode and a charge transportation layer, wherein the gain medium is the perovskite material or the mixed material containing the perovskite material; the laser device does not need to contain an additionally designed and machined resonant cavity, a laser threshold of the laser device is lower than or equal to 100 μJ cm−2 under femtosecond laser pumping, and the emitting threshold is lower than or equal to 1 mJ cm−2 under picosecond or nanosecond laser pumping or the gain medium is excited by continuous laser pumping to realize laser emission; and an ingredient of the perovskite material is A′2An−1BnX3n+1 or ABX3, wherein n is a positive integer, A′ is an organic amine cation, A is a monovalent cation, B is a metal cation, and X is an anion.
Preferably, a precursor solution of the perovskite material is prepared by dissolving A′ X, AX and BX2 in a solvent or dissolving the AX and the BX2 in the solvent, and the solvent comprises, but is not limited to, one or a mixture of several of DMF, DMSO, GBL, NMP, DMA and ACN.
Preferably, a material form of the gain medium comprises, but is not limited to, a thin film, a microcrystalline, a fluorescent powder, a nanocrystalline, a quantum dot and a monocrystalline.
Preferably, the A′ is the organic amine cation, which comprises, but is not limited to, one or a combination of several of a phenylethylamine cation PEA+, a phenylbutylamine cation PBA+, a 1,4-butanediamine cation BDA2+, a p-fluorophenylethylamine cation p-F-PEA+ and a 2-(4-methoxyphenyl)ethylamine cation MOPEA+; the A is the monovalent cation, which comprises, but is not limited to, one or a combination of several of a cesium ion Cs+, a methylamine ion MA+, a formamidine ion FA+, an ethylamine ion EA+, a hydrazine ion HA+, a guanidine ion GA+, an isopropylamine ion IPA+ and an imidazole ion IA+; the B is the metal cation, which comprises, but is not limited to, one or a combination of several of a lead ion Pb2+, a tin ion Sn2+, a germanium ion Ge2+, an indium ion In2+ and a bismuth ion Bi2+; and the X is the anion, which comprises, but is not limited to, one or a combination of several of a chloride ion Cl−, a bromide ion Br−, an iodide ion I−, a carbonate ion CO32− and an oleate ion OA−.
Preferably, an organic polymer, an organic small molecule, a metal, an oxide, a nitride, an inorganic salt, a dielectric material, an inorganic semiconductor material and a nanoparticle may be added into the gain medium, such as polymethyl methacrylate (PMMA), polyethylene glycol (PEG), polyethylene oxide (PEO), polyhydroxyethyl methacrylate (Poly-HEMA), 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene (TPBi), potassium bromide (KBr), potassium thiocyanate (KSCN), guanidine thiocyanate (GASCN), zinc oxide (ZnO), nickel oxide (NiO) and silicon dioxide (SiO2).
Preferably, a type of a pumping source comprises an optical pumping source, an electric pumping source or a combination of the two pumping sources, and a pumping mode comprises pulse pumping and continuous pumping; for a working mode of optical pumping, a structure of the external-cavity-free perovskite laser device consists of the substrate and the gain medium containing the perovskite material; and for a working mode of electric pumping or a combined pumping source containing the electric pumping, the structure of the device consists of the gain medium containing the perovskite material and one or more of the substrate, the electrode and the charge transportation layer.
Preferably, the substrate comprises a rigid material substrate: quartz, glass, a silicon wafer, sapphire and a metal; a flexible material substrate: a polymer material, comprising polyethylene terephthalate PET, polyethylene naphthalene PEN, polyimide PI, polydimethylsiloxane PDMS, polyurethane acrylate and a Nolan optical adhesive NOA; a metal foil material: a titanium foil, a copper foil and a silver foil; and paper and flexible glass, a thin silicon wafer and a Moscow mica sheet; and a shape of the substrate is a flat surface or a curved surface.
Preferably, a preparation method of the gain medium comprises: dissolving A′ X, AX and BX in a solvent or dissolving the AX and BX2 in the solvent to obtain a precursor solution of perovskite or a nanocrystalline, and then preparing the gain medium by a solution method; or preparing the gain medium with the A′ X, the AX and the BX or the AX and the BX2 by methods of evaporation, MOCVD, ALD, ink-jet printing, vapor deposition, magnetron sputtering and solid-state reaction; or preparing the gain medium by one or a combination of several of the processes above.
Preferably, in an implementation method of the gain medium prepared by the solution method, a growth size of a grain of the perovskite is controlled by adjusting a proportion of a mixed solvent, and a proportion and a concentration of a precursor material, and adding an anti-solvent, so that a size of the grain changes in a range of several nanometers to hundreds of microns, thus controlling a laser emitting threshold and a gain of the gain medium.
An application of an external-cavity-free low-threshold perovskite laser device is disclosed, wherein the external-cavity-free low-threshold perovskite laser device is applicable to fields of display, lighting, communication, sensing, energy, biomedicine, optoelectronic integration and chips.
The present invention has the following beneficial effects.
(1) According to the external-cavity-free low-threshold perovskite laser device prepared, the resonant cavity does not need to be additionally designed and machined to emit laser, so that complexity of preparing the laser device can be greatly reduced, and compactness and integration of the device can be improved.
(2) The external-cavity-free low-threshold perovskite laser device prepared has a low threshold, and laser may be emitted under a condition of low pumping energy, thus having a small energy consumption ratio.
(3) The external-cavity-free low-threshold perovskite laser device prepared has good compatibility with the flexible substrate and anon-planar substrate, and may also be widely used in a flexible substrate device and a non-planar substrate device in addition to a common planar rigid substrate, and moreover, the flexible laser device prepared has high robustness, thus having potential advantages in the field of biosensing.
Method for preparing external-cavity-free low-threshold perovskite laser device:
(1) Rigid Substrate and Flexible Substrate
The substrate comprises a rigid material substrate, such as quartz or glass, a silicon wafer and sapphire, and various metals; a flexible material substrate, such as a polymer material, comprising polyethylene terephthalate (PET), polyethylene naphthalene (PEN), polyimide (PI), polydimethylsiloxane (PDMS), polyurethane acrylate and a Nolan optical adhesive (NOA); a metal foil, such as a titanium foil, a copper foil and a silver foil; and paper and flexible glass, a thin silicon wafer and a Moscow mica sheet. A gain medium layer is made of a perovskite material or a mixed material containing the perovskite material.
(2) Preparation of Perovskite Material or Precursor Solution Containing Perovskite Material
An ingredient of the perovskite is A′2An−1BnX3n+1 (n=1, 2, 3, . . . ) or ABX3, wherein A′ is an organic amine cation, such as a phenylethylamine cation (PEA+), a phentermine cation (PBA+), a 1,4-butanediamine cation (BDA2+), a p-fluorophenylethylamine cation (p-F-PEA+) and a 2-(4-methoxyphenyl)ethylamine cation (MOPEA+); A is a monovalent cation, such as a cesium ion (Cs+), a methylamine ion (MA+), a formamidine ion (FA+), an ethylamine ion (EA+), a hydrazine ion (HA+), a guanidine ion (GA+), an isopropylamine ion (IPA+) and an imidazole ion (IA+). B is a metal cation, such as a lead ion (Pb2−), a tin ion (Sn2+), a germanium ion (Ge2+), an indium ion (In2+), a bismuth ion (Bi2+), a silver ion (Ag+) and a sodium ion (Na+); and X is an anion, which comprises a chloride ion (Cl−), a bromide ion (Br−), an iodide ion (I−), and the like. A′ X, AX and BX are dissolved in a solvent to obtain a precursor solution of perovskite or a nanocrystalline, and the perovskite material and an optoelectronic device are prepared by a solution method. Solvents of the precursor solution of perovskite comprise organic polar solvents, such as dimethylformamide (DMF), G-butyrolactone (GBL), dimethyl sulfoxide (DMSO), N, N-dimethylacetamide (DMA), acetonitrile (ACN) and an ionic liquid, and a mixed solvent of the solvents above in different proportions. Other materials, such as polymers of polymethyl methacrylate (PMMA), polyethylene glycol (PEG), polyethylene oxide (PEO), polyhydroxyethyl methacrylate (Poly-HEMA), and the like, small molecules of 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene (TPBi), potassium bromide (KBr), potassium thiocyanate (KSCN), guanidine thiocyanate (GASCN), and the like, and oxides, may also be added into the precursor solution. In the process, some solvents such as chlorobenzene (CB), ethyl acetate (EA), chloroform (CF) and toluene may be optionally added as anti-solvents, or one or more materials such as the 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene (TPBi), the polyethylene glycol (PEG), the polyethylene oxide (PEO) and the polymethyl methacrylate (PMMA) may be dissolved to adjust a course of crystallization. A material form comprises, but is not limited to, a thin film, a microcrystalline, a fluorescent powder, a nanocrystalline, a quantum dot, a monocrystalline, and the like.
(3) Preparation of External-Cavity-Free Low-Threshold Perovskite Laser Device
The perovskite of the gain medium layer is prepared on the substrate by spin coating, spray coating, knife coating, roll-to-roll printing and other solution methods. Or, the external-cavity-free perovskite laser device is prepared with A′ X, AX and BX or the AX and the BX by non-solution methods such as evaporation, vapor deposition, magnetron sputtering and solid-state reaction; or the external-cavity-free perovskite laser device is prepared by one or a combination of several of the processes above.
(4) Generation of External-Cavity-Free Low-Threshold Perovskite Laser
A pumping mode of the laser device may comprise optical pumping and electric pumping or combined pumping in different ways, and a type of a pumping source comprises a pulsed type and a continuous wave (CW) type. For the optical pumping, a structure of the device may consist of the substrate and the gain medium layer containing the perovskite material. For the electric pumping or the combined pumping containing the electric pumping, the structure of the device may consist of the gain medium containing the perovskite material and one or a combination of several of the substrate, an electrode and a charge transportation layer. The substrate comprises a rigid material substrate, such as quartz or glass, a silicon wafer and sapphire, and various metals; a flexible material substrate, such as a polymer material, comprising polyethylene terephthalate (PET), polyethylene naphthalene (PEN), polyimide (PI), polydimethylsiloxane (PDMS), polyurethane acrylate and a Nolan optical adhesive (NOA); a metal foil, such as a titanium foil, a copper foil and a silver foil; and paper and flexible glass, a thin silicon wafer and a Moscow mica sheet. A shape of the substrate may be a flat surface, a curved surface or other geometric configurations.
In this embodiment, a quartz substrate was used, and a precursor solution of perovskite was dissolved in 1 mL of DMF/(DMF+DMSO) at a ratio of 0.2 according to a molar ratio of MABr:PbBr2=1.05:1 to prepare 0.6 mol L−1 solution, subjected to spin coating at 3,000 rpm for 90 seconds, and then annealed at 90° C. for 5 minutes after spin coating, so as to obtain the external-cavity-free low-threshold perovskite laser device.
A quartz substrate was used, and a precursor solution of perovskite was dissolved in 1 mL of DMSO according to a molar ratio of MABr:PbBr2=1.05:1 to prepare 0.6 mol L−1 solution, and subjected to spin coating at 3,000 rpm for 90 seconds. About 50 seconds after starting the spin coating process, 200 μL of chlorobenzene was dropwise added onto the sample, and the sample was annealed at 90° C. for 5 minutes after spin coating, so as to obtain the perovskite device that had the same material ingredient and could only generate amplified spontaneous emission (ASE).
A PET substrate was used, and a precursor solution of perovskite was dissolved in 1 mL of DMF/(DMF+DMSO) at a ratio of 0.2 according to a molar ratio of MABr:PbBr2=1.05:1 to prepare 0.6 mol LV solution, subjected to spin coating at 3,000 rpm for 90 seconds, and then annealed at 90° C. for 5 minutes after spin coating, so as to obtain the external-cavity-free low-threshold perovskite laser device.
A glass sheet was used as a substrate, and a precursor solution of perovskite was dissolved in 1 mL of DMSO according to a molar ratio of FABr:PbBr2=1:1 to prepare 0.6 mol L−1 solution. The precursor solution was added with 5 mg of polyethylene oxide (PEO), subjected to spin coating at 3,000 rpm for 90 seconds, and then annealed at 90° C. for 5 minutes after spin coating, so as to obtain the external-cavity-free low-threshold perovskite laser device. Under femtosecond laser pumping, laser could be emitted, and a wavelength of the emitted laser was about 550 nm.
Polyethylene naphthalene (PEN) was used as a substrate, and a precursor solution of perovskite was dissolved in 1 mL of DMSO according to a molar ratio of MACl:MABr:PbBr2=1:4:5 to prepare 0.6 mol L−1 solution, subjected to spin coating at 3,000 rpm for 90 seconds, and then annealed at 90° C. for 5 minutes after spin coating, so as to obtain the external-cavity-free low-threshold perovskite laser device. Under femtosecond laser pumping, laser could be emitted, and a wavelength of emission was about 510 nm.
A large are of polyimide (PI) was used as a substrate, and a precursor solution of perovskite was dissolved in 1 mL of DMSO according to a molar ratio of MABr:PbBr2=1:1 to prepare 0.6 mol LV solution. The external-cavity-free perovskite laser device was prepared with the precursor solution by knife coating.
The above are only the preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Equivalent substitutions or changes made by those skilled in the art according to the technical solutions and the inventive concept of the present invention within the technical scope described by the present invention all belong to the scope of protection of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210786811.3 | Jul 2022 | CN | national |
