Continuous-wave perovskite polariton laser device and laser chip

Abstract

Disclosed in the present invention are a continuous-wave perovskite polariton laser device and laser chip. A gain medium of the continuous-wave perovskite polariton laser device is a perovskite material or a mixed material containing the perovskite material, and is in the form of a thin film, a microcrystal, fluorescent powder, a nanocrystal, a quantum dot or a single crystal. A perovskite gain medium is prepared by means of a solution method or a vacuum coating method, and by combining the perovskite gain medium with an optical resonant cavity, steady-state exciton-polariton condensation is formed by means of strong interaction between excitons and photons, and low-threshold continuous-wave polariton laser emission can be achieved without the need to meet conventional laser device population inversion conditions. The laser device can implement room-temperature low-threshold continuous-wave or pulse lase emission under various coherent and incoherent light sources or electrical excitation pumping, the threshold of the laser device is 1-3 orders of magnitude lower than the thresholds of conventional semiconductor laser devices, and the optimized threshold can reach 0.1-1 W / cm2 or below; and the laser device relates to a novel ultra-low power coherent light source technology.

Description

Continuous-wave perovskite polariton lasers and laser chips Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a low-threshold perovskite polariton laser and a laser chip that can operate in a continuous pumping mode. Background Art

[0002] When the coupling strength between excitons in a semiconductor and cavity photons confined by an optical microcavity is greater than the attenuation of the excitons and cavity photons, a hybrid quasiparticle, the exciton polariton, can form between them. This polariton is formed by the interaction between excitons and photons, exhibiting a hybrid state of half light and half matter. When the density reaches a certain level, as polaritons scatter from each other and release phonons, they condense to the lowest quantum energy state, accompanied by the leakage of their photon components from the optical microcavity, forming a polariton laser. Compared to traditional semiconductor lasers, polariton lasers do not require population inversion to achieve their realization. Therefore, their threshold is theoretically 1-2 orders of magnitude lower than that of photon lasers, making them more conducive to the generation of continuous-wave lasers.

[0003] Inorganic semiconductors, with their high dielectric constants and low hole effective masses, have low exciton binding energies, typically less than or approximately 10 meV, and readily thermally decompose into free electron-hole pairs at room temperature. Consequently, exciton-polariton condensation is typically observed only at relatively low temperatures. For example, the temperature at which polariton condensation occurs in GaAs and CdTe is around ~10 K, significantly limiting the development and application of exciton-polariton technology. In contrast, the excitons in organic materials are mostly Frenkel excitons, which exhibit very weak dielectric screening. Consequently, excitons in organic materials often have large binding energies, typically hundreds of meV, and high oscillator strengths, leading to higher critical temperatures for observing exciton-polariton condensation. However, the weak nonlinear effects and structural inhomogeneities of organic materials limit the spatial range and lifetime of exciton-polariton condensation. The weak Coulomb interactions between localized Frenkel excitons weaken the scattering between polaritons, retarding their condensation. Therefore, polariton lasing in organic materials often has a larger threshold, sometimes even larger than the threshold of stimulated emission lasing relying on population inversion.

[0004] Metal halide perovskites possess excellent optoelectronic properties and can be prepared via solution methods, exhibiting low crystallization temperatures, ease of processing, and low cost. These advantages have made them one of the most sought-after light-emitting and energy conversion materials, with widespread applications in fields such as LEDs and solar cells. However, the field of perovskite lasers remains relatively underrepresented, particularly in the area of ​​polariton lasers. It is noteworthy that perovskites possess high light absorption coefficients, long carrier diffusion lengths, low non-radiative recombination rates, high defect tolerance, and easily tunable emission wavelengths. Furthermore, perovskite materials typically possess exciton binding energies greater than room temperature thermal kinetic energy and high exciton concentrations. These factors contribute to the promising application of perovskite materials in the area of ​​polariton lasers, making them potential materials for studying the interaction between light and matter.

[0005] Although perovskite polariton lasers have been reported in the past, these lasers were all generated using pulsed light pumping. Continuous-wave (CW) perovskite lasers are the only way to electrically pumped perovskite lasers. Therefore, achieving CW perovskite polariton lasers is a key technical challenge.

[0006] Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention proposes a continuous-wave perovskite polariton laser, a laser chip, and a manufacturing method. By introducing a perovskite gain medium into an optical microcavity, a strong coupling relationship between excitons and photons is promoted. By further adjusting the detuning degree between the cavity mode and the polariton mode, the exciton-polariton properties are regulated, so that the microcavity can generate lasers under continuous-wave pumping, realizing an ultra-low-threshold continuous coherent light source.

[0008] A continuous-wave perovskite polariton laser comprises an optical microcavity, a spacer layer and a gain medium, wherein the gain medium is uniformly distributed in the microcavity.

[0009] The gain medium is a perovskite material or a mixed material containing a perovskite material, and is in the form of a thin film, microcrystal, phosphor, nanocrystal, quantum dot or single crystal, with a thickness of 10 nm to 1 mm.

[0010] Preferably, the composition of the perovskite material is A'2A n-1 B n X 3n+1 Or ABX3, wherein A' is an organic amine ion, A is a monovalent cation, B is a divalent metal cation, X is an anion, and n is a positive integer.

[0011] Preferably, the A' is phenethylamine (PEA + ), butylamine (BA + ), ethylamine (EA +) in one or more combinations; A cesium ion (Cs + ), methylamine ion (MA + ), formamidinium ion (FA + ), ethylamine ion (EA + ), guanidine ion (GA + ), isopropylamine ion (IPA + ) in one or more combinations; B is lead ion (Pb 2+ ), tin ions (Sn 2+ ), Germanium ions (Ge 2+ ), indium ions (In 2+ ), bismuth ion (Bi 2+ ) in one or more combinations; X is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) or a combination of one or more of ).

[0012] Preferably, the mixed material includes perovskite material, and one or more of organic material, quantum dot material, oxide material, III-V material, II-VI material, and rare earth material.

[0013] Preferably, the optical microcavity is a distributed Bragg reflector (DBR), a distributed feedback Bragg grating (DFB), a photonic crystal (PC), a continuous bound state structure (BIC) or a whispering gallery mode (WGM).

[0014] A continuous-wave perovskite polariton laser chip includes a continuous-wave perovskite polariton laser, an electrically driven light source, and a power supply. The micro-optical cavity of the continuous-wave perovskite polariton laser is fixed to the electrically driven light source. The electrically driven light source serves as a pump for the laser's micro-optical cavity. The power supply is connected to the electrically driven light source to drive the electrically driven light source to emit light.

[0015] Preferably, the electrically driven light source is a combination of one or more of commercial III-V group light emitting diodes (LEDs), organic light emitting diodes (OLEDs), quantum dot light emitting diodes (QD-LEDs), perovskite light emitting diodes (PeLEDs), micro light emitting diodes (micro-LEDs), laser diodes (LDs), and halogen tungsten lamps.

[0016] Preferably, the micro-optical cavity is fixed on the electrically driven light source by bonding, gluing, welding, coating or photolithography.

[0017] The preparation method of a continuous wave perovskite polariton laser specifically comprises the following steps:

[0018] Step 1: Preparation of optical microcavity

[0019] Step 2: Prepare perovskite materials and lasers

[0020] A'X, AX, BX2, and molecular additives are dissolved in a solvent to produce a perovskite precursor solution. Perovskite materials and laser devices are prepared using a solution method. The perovskite solution is injected into an optical microcavity and slowly heated on a hot plate. A temperature-increasing crystallization method is used to obtain perovskite single crystals, forming a perovskite microcavity device.

[0021] Preferably, a multilayer dielectric layer of silicon dioxide (SiO2) / titanium dioxide (TiO2) is deposited on quartz, sapphire or flexible substrate PET by sputtering or electron beam evaporation to form a distributed Bragg reflector (DBR) with high reflectivity. The thickness of each dielectric film is λ / 4n, where λ is the central wavelength of the gain medium emission and n is the refractive index of the dielectric layer material. A periodic array of metal pillars is deposited on a DBR reflector by thermal evaporation, with the height of the metal pillars ranging from 10nm to 1mm. The height of the metal pillars determines the cavity length of the optical microcavity, thereby effectively adjusting the detuning between the cavity mode and the exciton mode. Another DBR reflector is pressed face-to-face onto the DBR deposited with the metal pillar array, and a certain pressure is applied to press it, forming a vertical cavity surface emitting laser (VCSEL) structure.

[0022] Preferably, the perovskite thin film is obtained by spin coating.

[0023] Preferably, the perovskite film and the laser device are prepared by evaporation, MOCVD, ALD, inkjet printing, vapor deposition, magnetron sputtering, and solid-state reaction.

[0024] Preferably, the solvent is a mixture of any one or more of DMF, DMSO, GBL, and DMA.

[0025] Preferably, the molecular additive is a mixture of one or more of polymers, small molecules, and oxides.

[0026] Preferably, the polymer is polymethyl methacrylate (PMMA), polyethylene glycol (PEG), polyethylene oxide (PEO), polyvinyl pyrrolidone (PVP), the small molecule is potassium bromide (KBr), potassium thiocyanate (KSCN), guanidine thiocyanate (GASCN), and the oxide is NiOx, ZnO, SnO2.

[0027] The fabrication method for a continuous-wave perovskite polariton laser chip uses UV epoxy resin to directly attach a perovskite microcavity to a commercial gallium nitride (GaN) LED to form the perovskite laser chip. The GaN LED acts as a pump for the perovskite microcavity and is driven by a power supply.

[0028] The present invention has the following beneficial effects:

[0029] 1. This method uses solution processing and other low-cost methods to prepare high-quality perovskite gain media, and optimizes the quality of perovskite materials by optimizing the interface, effectively suppressing the grain boundary defects and photon scattering loss problems of perovskite films, and reducing the internal loss of laser devices.

[0030] 2. This method combines high-quality optical microcavities to promote strong coupling between excitons and photons, and prepares perovskite polariton laser devices with extremely low thresholds, which can emit laser beams under very low-power pumping conditions. Its threshold is 1-3 orders of magnitude lower than that of traditional semiconductor lasers, and its unoptimized laser threshold can reach 1-10W / cm 2 Or below, after optimization it can reach 0.1-1W / cm 2 Or below. The laser threshold can reach 1μJ / cm under pulsed light pumping without optimization. 2 Or below, can reach 0.1μJ / cm after optimization 2 or below.

[0031] 3. This method achieves oscillation feedback through an optical microcavity, promotes strong interaction between excitons and photons in the perovskite material, adjusts the thickness of the gain medium, realizes the microscopic property control of the exciton-polaritons in the optical microcavity, enhances their tendency to condense toward the ground state, and forms laser emission under continuous wave pumping mode, with an exciton lifetime of 1ps-100ms.

[0032] 4. The perovskite laser prepared by this method can be combined with various incoherent or coherent light sources (such as commercial III-V light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), quantum dot light-emitting diodes (QD-LEDs), perovskite light-emitting diodes (PeLEDs), micro light-emitting diodes (micro-LEDs), laser diodes (LDs), halogen tungsten lamps, etc.) to construct electrically pumped perovskite laser chips.

[0033] 5. The laser device prepared by this method has good temporal and spatial coherence and good polarization characteristics, and can be further used in low-threshold coherent light sources, slow light devices, quantum computing, optical computing, photonic chips, optoelectronic integration and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a characterization diagram of the continuous-wave green perovskite polariton laser device prepared in Example 1;

[0035] FIG2 is a continuous wave polariton laser produced by a single crystal perovskite microcavity at room temperature as prepared in Example 1;

[0036] FIG3 is the evolution process from polariton laser to photon laser in the perovskite microcavity in Example 1;

[0037] FIG4 shows the effect of detuning energy on polariton lasing in Example 1;

[0038] FIG5 is a schematic diagram of preparing a continuous wave electrically pumped perovskite laser chip in Example 2. DETAILED DESCRIPTION

[0039] The present invention will be further explained below with reference to the accompanying drawings;

[0040] Example 1

[0041] This embodiment introduces a method for preparing a continuous-wave green perovskite polariton laser device. The specific steps are as follows:

[0042] Step 1: 10 groups of SiO2 / TiO2 dielectric layers are sputtered sequentially on a quartz substrate. The thickness of the SiO2 layer is 91 nm and the thickness of the TiO2 layer is 55 nm, forming a DBR mirror with high reflectivity (>98%).

[0043] Step 2: Use thermal evaporation to periodically deposit gold columns on the DBR reflector through the designed mask. The diameter of the gold columns is 1 mm and the period is 1 mm.

[0044] Step 3: Spin-coat a layer of PMMA onto the DBR mirror to improve surface hydrophobicity. The PMMA solution concentration was 5 mg / ml, and the spin-coating speed was 3000 rpm. After spin-coating, heat on a hot plate at 120°C for 10 minutes to cure.

[0045] Step 4: Glue the top DBR reflector and the bottom DBR reflector prepared in step 3 face to face and fix them with clips to form a vertical microcavity structure.

[0046] Step 5: The perovskite precursor solution is prepared by dissolving FABr:MABr:PbBr2 with a molar ratio of 0.1:0.9:1 in a solution with a concentration of 1 mol L -1 The mixture was added into 1 mL of DMF and DMSO mixed solvent, wherein the ratio of DMF to DMSO was 4:1.

[0047] Step 6: Add 5 mg of molecular additive PVP to passivate defects.

[0048] Step 7: Inject the perovskite solution into the microcavity along the edge through a pipette, and use the capillary force to make the perovskite solution spread evenly in the microcavity.

[0049] Step 8: Place the microcavity sample containing the perovskite solution on a hot stage, and slowly increase the temperature from 30°C to 80°C at a rate of 2°C per hour. Continue heating for 24 hours after reaching 80°C. After the hot stage temperature gradually cools to room temperature, remove the microcavity device, and the perovskite polariton laser device is completed.

[0050] Step 9: Place the device on an inverted microscope platform, focus a continuous laser with a wavelength of 405 nm onto the gain medium layer of the device through a 100X lens, and place a wheel-type attenuation plate in front of the objective lens to adjust the excitation intensity.

[0051] Step 10: The light beam generated by the device passes through the microscope objective lens, then through a 4f system, and is introduced into the slit entrance of the imaging spectrometer to measure its angle-resolved spectrum.

[0052] Step 11: Place a polarizer in front of the imaging spectrometer, rotate the polarizer angle, and measure the polarization of the generated laser beam.

[0053] Step 12: The polariton laser device's light beam is split into two beams after passing through a beam splitter. The two beams are then directed into fiber-coupled single-photon detectors to measure the temporal and spatial coherence of the beams.

[0054] Figure 1 shows the preparation and material characterization of a perovskite polariton laser. (a) is a schematic diagram of a continuous-wave perovskite polariton laser. A perovskite single crystal is sandwiched between a pair of highly reflective DBRs, achieving continuous-wave lasing through the interaction between excitons and photons. (b) is a scanning transmission electron microscope (STEM) and energy dispersive spectroscopy (EDS) image of the DBR structure, showing the double-layer SiO2 and TiO2 dielectric layers. (c) is a flow chart of the single-crystal perovskite microcavity preparation process. (d) is a scanning electron microscope (SEM) image of a MAPbBr3 perovskite single crystal, showing that the perovskite dielectric layer is very smooth and has no grain boundaries, resulting in minimal photon scattering losses. (e) is a fluorescence microscope image of a MAPbBr3 perovskite single crystal, showing a very uniform fluorescence distribution with no obvious defects. (f) is an XRD pattern of a MAPbBr3 single crystal and polycrystalline sample, showing that the single crystal XRD pattern has fewer impurity peaks and a narrower peak shape, indicating a higher phase purity of the single crystal perovskite. g is the absorption and fluorescence (PL) spectra of the MAPbBr3 perovskite single crystal. h is the transient PL decay curve of the perovskite sample (excitation wavelength: 400 nm; excitation intensity: 4.2 μJ cm -2 ), where FMPB is FA 0.1 MA 0.9 The abbreviation of PbBr3 perovskite. i is the fluorescence quantum efficiency (PLQY) of different perovskite samples as a function of excitation intensity. It can be seen that through the strategies of A-site cation regulation, mixed solvents, molecular additive passivation, surface hydrophobicity regulation, etc., the final FA 0.1 MA 0.9 The PbBr3 perovskite sample has a longer fluorescence lifetime (420ns) and higher fluorescence quantum efficiency (>30%).

[0055] Figure 2 shows the continuous wave polariton laser of a single crystal perovskite microcavity at room temperature. a is the evolution of the emission spectrum under different continuous wave pump intensities. The inset shows the emission near-field images with pump intensities below (left), close to (middle) and above (right) the threshold. The scale bar is 20 μm. b is the variation of the light output intensity and spectral half-peak width with continuous pump intensity, and the pump spot diameter is 18 μm. The pump intensity reported in this work is the original intensity of the incident beam (without any correction for reflection and transmission losses). c is the spatiotemporal coherence of the continuous wave exciton laser. Above the threshold, the first-order coherence g is measured using a Michelson interferometer. 1 (τ). The red solid line represents the Gaussian fit to the data. The inset shows the Michelson interference pattern at zero delay. d is the value of the laser exceeding the threshold (3.2P th ). The straight line represents the dispersion relation of the exciton. The solid parabolic curve represents the dispersion relation of the cavity photon. The dotted line represents the dispersion curve of the lower polariton branch. Above the laser threshold, polaritons condense at the bottom of the lower branch to produce polariton laser. e is the occupation distribution curve of polaritons in various energy states when the pump intensity is lower than 0.8Pth, about 1.0Pth and higher than 2.0Pth, drawn on a semi-logarithmic scale. For each pump intensity, the zero point of the energy scale corresponds to the spatial plane wave vector k / / =0 ground state energy, the horizontal axis represents the relative k / / = 0. We assign the ground-state polariton occupied density of states to 1. The blue dashed line represents the Maxwell-Boltzmann distribution function at room temperature, which agrees well with the polariton occupied state distribution curve at threshold, confirming Bose-Einstein condensation. f is a comparison of the continuous-wave lasing thresholds of lasers based on different types of semiconductor materials. It can be seen that the perovskite polariton threshold we achieved is 27 times lower than that of traditional III-V semiconductors, reaching 1-2 orders of magnitude.

[0056] Figure 3 shows the evolution of polariton laser to photon laser in a single crystal perovskite microcavity. a is the emission intensity-pump flux curve of the single crystal perovskite microcavity. -2 and 12.4 μJ cm -2When corresponds to polariton laser and photon laser respectively. A 400nm fs laser (pulse width of 270fs, repetition frequency of 50kHz) is used to pump the microcavity sample. b is the FWHM and wavelength blue shift with the change of pump flux, showing significant changes at the two thresholds. The shaded area is the area near the threshold. c is the spontaneous emission spectrum, polariton laser and photon laser spectrum of single crystal perovskite. It can be found that the spectrum of polariton laser is blue-shifted compared with the photon laser. d is the polarization characteristics of spontaneous radiation, polariton laser and photon laser. It can be found that both exciton polariton laser and photon laser have obvious polarization characteristics, but the polarization degree of photon laser is stronger. e is the second-order coherence function g of polariton laser and photon laser 2 (0). The gray shaded area indicates the photon laser state. f, g, h, i show the angle-resolved emission spectra of the single crystal perovskite microcavity at different pump flow rates, where (f) P = 0.8Pth1, (g) P = 2Pth1, (h) P ~ Pth2, and (i) P = 1.6Pth2. Pth1 and Pth2 correspond to the polariton laser and photon laser thresholds, respectively. It can be seen that the energy distribution in the polariton laser mode is at the bottom of the polariton lower branch, while the energy distribution in the photon laser mode is at the bottom of the cavity mode, with a significant blue shift.

[0057] Figure 4 shows the effect of detuning energy on polariton lasing. Detuning energy refers to the energy difference (Δ) between the cavity mode and the exciton mode. Figures a, b, and c are the angle-resolved emission spectra of the single-crystal perovskite microcavity at Δ = -50, Δ = -35, and Δ = -18 meV, respectively. It can be seen that as the detuning energy (absolute value) decreases, the polaritons condense better. Figure d is the polariton occupation function at different detuning energies. Figure e is the emission intensity-pump flux characteristic at detuning energies Δ = -78, -50, -35, and -18 meV. It can be seen that the threshold decreases as the detuning energy (absolute value) decreases. Figure f is the relationship between the laser threshold and the detuning energy. For Δ < -60 meV and Δ > 0 meV (positive detuning energy), no continuous-wave polariton lasing was observed.

[0058] Example 2

[0059] This embodiment introduces a method for preparing a continuous-wave electrically pumped perovskite laser chip. The specific steps are as follows:

[0060] Step 1: 10 groups of SiO2 / TiO2 dielectric layers are sputtered sequentially on a quartz substrate. The thickness of the SiO2 layer is 91 nm and the thickness of the TiO2 layer is 55 nm, forming a DBR mirror with high reflectivity (>98%).

[0061] Step 2: Use thermal evaporation to periodically deposit gold columns on the DBR reflector through the designed mask. The diameter of the gold columns is 1 mm and the period is 1 mm.

[0062] Step 3: Spin-coat a layer of PMMA onto the DBR mirror to improve surface hydrophobicity. The PMMA solution concentration was 5 mg / ml, and the spin-coating speed was 3000 rpm. After spin-coating, heat on a hot plate at 120°C for 10 minutes to cure.

[0063] Step 4: Glue the top DBR reflector and the bottom DBR reflector prepared after step 3 face to face and fix them with clips to form a vertical microcavity structure.

[0064] Step 5: The perovskite precursor solution is prepared by dissolving FABr:MABr:PbBr2 with a molar ratio of 0.1:0.9:1 in a solution with a concentration of 1 mol L -1 The mixture was added into 1 mL of DMF and DMSO mixed solvent, wherein the ratio of DMF to DMSO was 4:1.

[0065] Step 6: Add 5 mg of molecular additive PVP to passivate defects.

[0066] Step 7: Inject the perovskite solution into the microcavity along the edge through a pipette. Using capillary force, the perovskite solution will diffuse evenly in the microcavity.

[0067] Step 8: Place the microcavity sample containing the perovskite solution on a hot stage and slowly increase the temperature from 30°C to 80°C, increasing by 2°C every hour. Continue heating for 24 hours after reaching 80°C. After the hot stage temperature gradually cools to room temperature, remove the microcavity device.

[0068] Step 9: Adhere a commercial GaN LED chip to the bottom of the microcavity device using epoxy resin.

[0069] Step 10: Use a DC current source to drive the GaN LED and collect the light beam emitted from the top of the microcavity device into a spectrometer to measure the spectrum. Place a long-pass filter (>500nm) in front of the spectrometer to filter the pump light source.

[0070] Figure 5 shows the fabrication and results of an electrically pumped laser chip. (a) Schematic diagram of an electrically injected perovskite laser chip, powered by a DC current source feeding a 450nm GaN LED. (b) The emission intensity and spectral half-maximum width (FWHM) of the perovskite polariton laser chip change with the GaN LED DC drive current. It can be seen that the emission intensity rises significantly near the current threshold. Simultaneously, the spectral FWHM drops sharply from 1.8nm to 0.8nm. These features confirm the generation of laser light. (c) Laser spectra of microcavities of varying lengths (adjusted by single crystal thickness). At a drive current of 60mA, tunable laser wavelengths from 545 to 557nm were achieved.

[0071] Example 3

[0072] This embodiment introduces a method for preparing a continuous-wave near-infrared perovskite polariton laser device. The specific steps are as follows:

[0073] Step 1: 10 groups of SiO2 / TiO2 dielectric layers are sputtered sequentially on a quartz substrate. The thickness of the SiO2 layer is 130nm and the thickness of the TiO2 layer is 78nm, forming a DBR reflector with high reflectivity (>98%) in the near-infrared region.

[0074] Step 2: Use thermal evaporation to periodically deposit gold columns on the DBR reflector through the designed mask. The diameter of the gold columns is 1 mm and the period is 1 mm.

[0075] Step 3: Spin-coat a layer of PMMA onto the DBR mirror to improve surface hydrophobicity. The PMMA solution concentration was 5 mg / ml, and the spin-coating speed was 3000 rpm. After spin-coating, heat on a hot plate at 120°C for 10 minutes to cure.

[0076] Step 4: Glue the top DBR reflector and the bottom DBR reflector prepared after step 3 face to face and fix them with clips to form a vertical microcavity structure.

[0077] Step 5: The perovskite precursor solution is prepared by dissolving FABr:MABr:PbBr2 with a molar ratio of 0.1:0.9:1 in a solution with a concentration of 1 mol L -1 The mixture was added into 1 mL of DMF and DMSO mixed solvent, wherein the ratio of DMF to DMSO was 4:1.

[0078] Step 6: Add 5 mg of molecular additive PVP to passivate defects.

[0079] Step 7: Inject the perovskite solution into the microcavity along the edge through a pipette. Using capillary force, the perovskite solution will diffuse evenly in the microcavity.

[0080] Step 8: Place the microcavity sample containing the perovskite solution on a hot stage and slowly increase the temperature from 30°C to 120°C, increasing by 3°C every hour. Continue heating for 24 hours after reaching 120°C. After the hot stage gradually cools to room temperature, remove the microcavity device. The perovskite polariton laser device is now fabricated.

[0081] Step 9: Place the device on an inverted microscope platform, focus a continuous laser with a wavelength of 532nm onto the gain medium layer of the device through a 100x lens, and place a wheel-type attenuation plate in front of the objective lens to adjust the excitation intensity.

[0082] Step 10: The light beam generated by the device passes through the microscope objective lens, then through a 4f system, and is introduced into the slit entrance of the imaging spectrometer to measure its angle-resolved spectrum.

[0083] Step 11: Place a polarizer in front of the imaging spectrometer, rotate the polarizer angle, and measure the polarization of the generated laser beam.

[0084] Step 12: The polariton laser device's light beam is split into two beams after passing through a beam splitter. The two beams are then directed into fiber-coupled single-photon detectors to measure the temporal and spatial coherence of the beams.

[0085] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any researchers and technicians familiar with the field, within the technical scope described in the present invention, who make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A continuous wave perovskite polariton laser comprising an optical microcavity, a spacer layer and a gain medium, characterized in that: The preparation method of the continuous wave perovskite polariton laser is as follows: Step 1: Preparation of optical microcavity A periodic metal column array is deposited on a DBR reflector, wherein the height of the metal column is 10 nm to 1 mm; another DBR reflector faces downward and is glued face to face with the DBR on which the metal column array is deposited, and a certain pressure is applied to press the DBR to form a vertical microcavity surface emitting laser VCSEL structure; Step 2: Preparation of perovskite materials A'X, AX, BX2 and molecular additives are dissolved in a solvent to obtain a perovskite precursor solution, and a perovskite material is prepared by a solution method, wherein A' is an organic amine ion, A is a monovalent cation, B is a divalent metal cation, and X is an anion; Step 3: Prepare perovskite laser The perovskite solution is injected into the optical microcavity and placed on a hot stage for slow heating and crystallization, so that the perovskite single crystal is grown in situ to obtain a continuous wave perovskite polariton laser. The continuous wave perovskite polariton laser operates in a continuous wave pumping mode, based on the polariton condensation emission, and the laser threshold is as low as 0.4 W cm -2 ; The gain medium is a perovskite material, which is evenly distributed in the microcavity.

2. The continuous wave perovskite polariton laser according to claim 1, characterized in that: The composition of the perovskite material is A'2A n-1 B n X 3n+1 or ABX3, n is a positive integer; A' is phenethylamine PEA + , butylamine BA + , ethylamine EA + A cesium ion Cs + , methylamine ion MA + , formamidinium ion FA + , ethylamine ion EA + , guanidine ion GA + 、Isopropylamine ion IPA + One or more combinations thereof; B is lead ion Pb 2+ 、Sn 2+ 、Ge 2+ 、Indium ion In 2+ 、Bi ion 2+ One or more combinations of; X is a chloride ion Cl - 、Br - 、Iodide ion I - A combination of one or more of .

3. The continuous wave perovskite polariton laser according to claim 1, characterized in that: On quartz, sapphire or flexible substrate PET, a multi-layer dielectric layer of silicon dioxide SiO2 / titanium dioxide TiO2 is deposited by sputtering or electron beam evaporation to form a distributed Bragg reflector DBR with high reflectivity; the thickness of each dielectric film is λ / 4n, where λ is the central wavelength of the gain medium light emission and n is the refractive index of the dielectric layer material.

4. The continuous wave perovskite polariton laser according to claim 1, characterized in that: The solvent is any one or more mixtures of DMF, DMSO, GBL, and DMA; the molecular additive is any one or more mixtures of polymers, small molecules, and oxides.

5. The continuous wave perovskite polariton laser according to claim 4, characterized in that: The polymers are polymethyl methacrylate PMMA, polyethylene glycol PEG, polyethylene oxide PEO, polyvinyl pyrrolidone PVP, the small molecules are potassium bromide KBr, potassium thiocyanate KSCN, guanidine thiocyanate GASCN, and the oxides are NiOx, ZnO, and SnO2.

6. A continuous wave perovskite polariton laser chip, comprising a laser, an electrically driven light source and a power supply, characterized in that: The laser is a continuous wave perovskite polariton laser as described in any one of claims 1 to 5; the micro-optical cavity of the continuous wave perovskite polariton laser is fixed on an electrically driven light source; the electrically driven light source serves as a pump for the laser micro-optical cavity; the power supply is connected to the electrically driven light source to drive the electrically driven light source to emit light.

7. The continuous wave perovskite polariton laser chip according to claim 6, characterized in that: The micro-optical cavity is fixed on the electrically driven light source by bonding, gluing, welding, coating or photolithography, and the electrically driven light source serves as a pump for the micro-optical cavity.

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