A magnetic field effect measurement system and method for a variable temperature steady state transient electroluminescent device

Abstract

This invention relates to a magnetic field effect measurement system and method for a variable-temperature steady-state and transient electroluminescent device. The system includes an optoelectronic device measurement system comprising an electroexcitation measurement module, a sample module, a spectral module, and a time module. By replacing or removing the reflectors in the incident light path and the acquisition light path within the modules, the magnetic field effect of the variable-temperature steady-state and transient electroluminescence properties of the electroluminescent device under different magnetic field directions can be measured. The measurement method of this invention is simple in principle and easy to operate, and can measure multiple steady-state and transient optoelectronic properties of electroluminescent devices under various excitation modes, temperatures, and external magnetic field environments.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic testing technology, and particularly relates to a comprehensive testing system and measurement method for measuring the steady-state and transient electroluminescence properties and magnetic field effects of electroluminescent devices under varying temperature conditions. Background Technology

[0002] The light-emitting mechanism of electroluminescent devices is an important research topic in the field of optoelectronics, primarily focusing on the properties and physical processes related to the excited states within the device. The performance of optoelectronic devices, such as external quantum efficiency, the position and width of the emission peak, corresponds to the utilization efficiency and properties of excitons within them. Therefore, research on the light-emitting mechanism of optoelectronic devices is of great significance for understanding and developing optoelectronic materials.

[0003] Excited states in optoelectronic materials possess spin properties, and these spin properties play a crucial role in the radiative transitions of excitons. Based on their spin properties, they are classified into singlet and triplet states. According to the spin selection rule, only singlet excited states can be effectively utilized. In recent years, researchers have discovered that an applied magnetic field can influence the spin-related processes of excited states in electroluminescent devices. By controlling the ratio of singlet to triplet excited states, the efficiency and luminescence properties of the electroluminescent device can ultimately be affected, resulting in enhanced electroluminescence due to magnetic field effects.

[0004] Common research methods for optoelectronic devices mainly include measuring current characteristic curves, luminescence intensity characteristic curves and electroluminescence spectra, as well as measuring luminescence lifetime and decay processes. Therefore, it is necessary to measure and characterize the steady-state and transient electrical and electroluminescence properties of the devices. However, common commercial optoelectronic device measurement instruments often only have partial functions, and commercial optoelectronic detection equipment usually cannot integrate a stable and adjustable external electromagnetic field. In addition, commercial instruments are usually only suitable for millimeter-sized optoelectronic devices, and general commercial instruments cannot provide the testing conditions for the microscopic systems required for micro- and nano-sized devices.

[0005] Therefore, there is an urgent need to develop a testing method and instrument system for steady-state and transient optoelectronic devices with multiple sizes, variable temperatures, and integrated magnetic fields. Summary of the Invention

[0006] This invention aims to provide a magnetic field effect measurement system and method for variable-temperature steady-state and transient electroluminescent devices. It can measure the steady-state current characteristic curve, steady-state light emission characteristic curve, steady-state electroluminescence spectrum, transient current response, transient electroluminescence decay process and magnetic field effect of optoelectronic devices in a high-vacuum environment and a constant-temperature system with adjustable temperature from the critical temperature of liquid helium to room temperature.

[0007] To address the aforementioned technical problems, according to one aspect of the present invention, a magnetic field effect measurement system for achieving steady-state and transient photoelectric properties of optoelectronic devices under varying temperature conditions is provided. The magnetic field effect measurement system includes at least an electro-excitation measurement module, a sample module, a spectral module, and a time module. The electro-excitation measurement module controls and adjusts the electro-excitation output mode, and is connected to the sample module. The sample module switches the incident light path and controls the excitation mode for different magnetic field directions. The spectral module filters the incident light from the sample module, switches the light path for collecting the emission signal, and outputs measurement information corresponding to the optical path. The time module switches the optical path of the emission signal entering the spectral module and outputs transient emission information.

[0008] In one embodiment of the present invention, the electro-excitation measurement module includes at least a light source, a single-channel steady-state source meter, a dual-channel steady-state and transient source meter, a gigahertz signal generator, a gigahertz power amplifier, and a junction box. One output of the gigahertz signal generator is connected to the gigahertz power amplifier, and the other output is connected to the time module. The electro-excitation measurement module is connected to the devices in the sample module through the junction box.

[0009] In one embodiment of the present invention, the sample module includes at least a sample stage, a cryostat, an electromagnetic field, and a first reflector, a second reflector, and a third reflector for switching the incident light path. The first reflector is detachably installed in the sample module, and the device under test sample is fixed in the sample stage of the cryostat.

[0010] In one embodiment of the present invention, when the first reflector is disassembled, the incident light is reflected to the second reflector, thereby enabling the incident light to excite the device under test sample with a perpendicular magnetic field. When the first reflector is installed, the incident light is reflected to the third reflector, thereby enabling the incident light to excite the device under test sample with a parallel magnetic field.

[0011] In one embodiment of the present invention, the spectral module includes at least a switchable filter group, an adjustable attenuator group, four achromatic lenses, three mirrors for switching the light collection path of the sample emission from the device under test, a silicon photodiode, a grating spectrometer, and a fiber optic spectrometer. The grating spectrometer includes a first photomultiplier tube. The first achromatic lens, the switchable filter group, the adjustable attenuator group, the fourth mirror, the fifth mirror, the sixth mirror, and the silicon photodiode are sequentially arranged in the light collection path of the sample emission from the device under test. The fourth mirror, the fifth mirror, and the sixth mirror are all detachably mounted within the spectral module. The second achromatic lens, the third achromatic lens, and the fourth achromatic lens are respectively arranged in the reflected light paths of the fourth mirror, the fifth mirror, and the sixth mirror. The grating spectrometer and the fiber optic spectrometer are respectively fixed in the reflected light paths of the fourth mirror and the sixth mirror.

[0012] In one embodiment of the present invention, the first achromatic lens is used to collimate the light emission of the collimating device, the second, third and fourth achromatic lenses are used to focus the light emission signal, and the silicon photodiode is used to collect the light emission signal when the fourth, fifth and sixth reflectors are all disassembled.

[0013] In one embodiment of the present invention, the timing module includes at least a second photomultiplier tube and a single-photon counter. The second photomultiplier tube replaces the first photomultiplier tube of the grating spectrometer. After the second photomultiplier tube converts the emission signal into a current signal, the current signal is amplified by a high-frequency wideband amplifier unit and converted into a voltage signal. The voltage signal is read by an oscilloscope to obtain the transient emission response. The single-photon counter replaces the fiber optic spectrometer, converts the emission signal into a level signal, and uses a time-to-digital converter to obtain the transient electroluminescence information of the device under test sample.

[0014] In one embodiment of the present invention, the electro-excitation measurement module further includes a junction box, wherein the single-channel steady-state source meter, the dual-channel steady-state transient source meter, the gigahertz signal generator and the gigahertz power amplifier are connected to the devices in the sample module through the junction box, and the electro-excitation measurement module is used to realize real-time synchronous reading of electrical signals, light emission signals and magnetic field strength signals.

[0015] In one embodiment of the present invention, the temperature range of the low-temperature thermostat is 5 K to 300 K.

[0016] In one embodiment of the present invention, the electromagnetic field is integrated with a low-temperature thermostat.

[0017] In one embodiment of the present invention, the magnetic field strength of the electromagnetic field varies continuously within the range of -300 mT to 300 mT.

[0018] This invention also proposes a magnetic field effect measurement method using the aforementioned magnetic field effect measurement system for variable-temperature steady-state and transient electroluminescent devices. The measurement method includes: controlling the electro-excitation measurement module and switching the electro-excitation output mode; changing the equipment in the sample module, switching the incident optical path, and selecting the excitation mode of the device sample under test; changing the equipment in the spectral module, switching the outgoing optical path, changing the optical path, and outputting the imaging, steady-state electroluminescence spectrum, electroluminescence intensity, or electroluminescence transient lifetime test results of the device sample under test.

[0019] In one embodiment of the present invention, modifying the equipment within the sample module further includes: installing or removing the first reflector, switching the incident light path of the light source, and exciting the vertical magnetic field or parallel magnetic field of the sample of the device under test.

[0020] In one embodiment of the present invention, changing the equipment within the spectral module further includes: installing or removing the fourth, fifth, or sixth reflecting mirror respectively, and switching different optical paths.

[0021] The present invention has the following technical effects: 1. This invention integrates a variety of electro-excitation devices and measuring instruments, including a single-channel steady-state source meter, a dual-channel steady-state and transient source meter, a gigahertz signal generator, a gigahertz power amplifier, a cryostat, an electromagnet, a grating spectrometer, a photomultiplier tube, a scientific camera, a silicon photodetector, a transimpedance amplifier and digital multimeter, a fiber optic spectrometer, a single-photon counter and a time-to-digital converter (TDC). It can realize device imaging under varying temperature and magnetic field conditions in a vacuum environment, test steady-state electroluminescence spectra and intensities, and measure transient electroluminescence decay curves. It can comprehensively characterize the steady-state and transient photoelectric properties of optoelectronic devices.

[0022] 2. This invention can use a variety of electrical excitation devices. Compared with traditional commercial instruments, this invention can provide a variety of different electrical excitation modes, such as pulse excitation modes with adjustable pulse width and pulse interval. At the same time, by integrating electromagnets, the magnetic field effect of these devices under different excitation modes can be realized.

[0023] 3. This invention uses a combination of a grating spectrometer and a photomultiplier tube, a single-photon counter and a TDC to measure transient electroluminescence and luminescence decay. Compared with traditional commercial instruments, it can obtain transient luminescence information with high spectral resolution at the sub-nanometer level, and also obtain transient luminescence information with high temporal resolution at the sub-nanosecond level. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the overall structure of the magnetic field effect measurement system for the variable-temperature steady-state and transient electroluminescent device of the present invention.

[0025] Figure 2 This is a test optical path diagram of a 3F6-2BT OLED device, a preferred example of the variable-temperature steady-state transient luminescence magnetic field effect measurement system of the present invention, as well as a variable-temperature steady-state luminescence measurement result diagram and an electroluminescence magnetic field effect result diagram of the device.

[0026] Figure 3 This is a test optical path diagram of a t-DABNAB OLED device, a preferred example of the variable-temperature steady-state transient luminescence magnetic field effect measurement system of the present invention, as well as transient response of electroluminescence and magnetic field effect results of electroluminescence in pulse mode.

[0027] Figure 4 This is a preferred example of the temperature-dependent steady-state transient luminescence magnetic field effect measurement system of the present invention, showing the test optical path diagram of a t-DABNAB OLED device, as well as the measurement of transient decay and magnetic field effect of temperature-dependent electroluminescence.

[0028] Figure reference numerals: 1-Single-channel steady-state source meter; 2-Dual-channel steady-state and transient source meter; 3-Gigahertz signal generator; 4-Gigahertz power amplifier; 5-Jack box; 6-Replaceable light source; 7-First reflector; 8-Second reflector; 9-Third reflector; 10-Electromagnetic field; 11-Liquid helium-free closed-loop vacuum cryostat; 12-Removable and replaceable printed circuit board sample stage for different samples; 13-First achromatic lens; 14-Switchable filter group; 15-Adjustable attenuator group; 16-The... 17-Five-18-Six-19-Second-Achromatic Lens; 20-Third-Achromatic Lens; 21-Fourth-Achromatic Lens; 22-Scientific Camera; 23-Raster Spectrometer; 24-First Photomultiplier Tube; 25-Silicon Photodiode; 26-Transimpedance Amplifier; 27-Digital Multimeter; 28-Fiber Optic Spectrometer; 29-Second-1 Photomultiplier Tube; 30-High-Frequency Wideband Amplifier Unit; 31-Oscilloscope; 32-Single-Photon Counter; 33-Time-to-Digital Signal Converter. Detailed Implementation

[0029] 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.

[0030] Example 1 like Figure 1As shown, this invention provides a magnetic field effect measurement system for a variable-temperature steady-state and transient electroluminescent device, comprising an electroexcitation measurement module, a sample module, a spectral module, and a time module. The electroexcitation measurement module controls and adjusts the electroexcitation output mode, and the electroexcitation measurement module is electrically connected to the sample module.

[0031] Specifically, the electro-excitation measurement module includes at least a single-channel steady-state source meter 1, a dual-channel steady-state transient source meter 2, a gigahertz signal generator 3, a gigahertz power amplifier 4, a junction box 5, and a light source 6.

[0032] Among them, the single-channel steady-state source meter 1 can manually or programmatically adjust the output mode to achieve the switching between constant voltage and constant current output modes. The output signal of the single-channel steady-state source meter 1 is connected to the device in the sample module through the junction box 5.

[0033] The multi-channel steady-state and transient source meter 2 can adjust the output mode manually or by program control, thereby achieving the switching between constant voltage and current output mode and pulse voltage and current output mode. The output signal of the multi-channel steady-state and transient source meter 2 is connected to the device in the sample module through the junction box 5.

[0034] The gigahertz signal generator 3 can adjust its output mode manually or programmatically to achieve microsecond-level pulse signals. The signal output from the gigahertz signal generator 3 is amplified by the gigahertz power amplifier 4 to obtain a pulse signal with unchanged time characteristics but higher power, which is then connected to the device in the sample module through the junction box 5. One output of the gigahertz signal generator 3 is connected to the gigahertz power amplifier 4, and the other output is connected to the timing module.

[0035] Junction box 5 enables electrical connection between the electro-excitation measurement module and the sample module. The light source 6 is a replaceable light source, preferably including an LED, a steady-state laser, a picosecond laser, a femtosecond laser, etc. Preferably, the output mode of all devices within the electro-excitation measurement module is controlled and adjusted via an external computer program.

[0036] According to the present invention, the sample module switches the incident light path to control the excitation mode of different magnetic field directions. Specifically, the sample module includes at least the sample of the device to be measured, a first reflector 7, a second reflector 8, a third reflector 9, an electromagnetic field 10, a cryostat 11, and a sample stage 12. The first reflector 7, the second reflector 8, and the third reflector 9 are used to switch the incident light path. The cryostat 11 is preferably a liquid helium-free closed-loop vacuum cryostat with a temperature range of 5 K to 300 K. The magnetic field strength of the electromagnetic field 10 continuously varies from -300 mT to 300 mT, and the electromagnetic field 10 is integrated with the cryostat 11. Thus, the cryostat 11 can achieve continuous temperature variation within the range of 5-330 K and a continuously variable magnetic field of ±300 mT in a vacuum environment.

[0037] The sample stage 12 is preferably a detachable, replaceable printed circuit board sample stage for different samples, with the device under test (DUT) sample fixed in the sample stage 12. The sample stage 12 is a gold-plated ultra-thin printed circuit board, with one side connected to a spring-loaded terminal block inside the cryostat 11 and the other side connected to the electrode of the DUT sample. The sample stage 12 is hung and fixed on the sample holder of the cryostat 11. Preferably, the sample stage 12 is fixed to the sample holder of the cryostat 11 by three copper M2 screws.

[0038] The first reflecting mirror 7 is detachably installed inside the sample module and is used to switch the incident light path. When the first reflecting mirror 7 is removed, it is taken out of the incident light path of the light source 6. The incident light is reflected to the second reflecting mirror 8. The incident light is reflected by the second reflecting mirror 8 and enters through the front optical window of the low-temperature thermostat 11, that is, it is incident on the sample of the device under test along the direction of the perpendicular magnetic field, thus exciting the sample. This achieves the excitation of the sample of the device under test by the incident light perpendicular to the magnetic field.

[0039] When the first reflector 7 is installed, that is, the first reflector 7 is added to the incident light path of the light source 6 so that the incident light is incident on the third reflector 9, the incident light is reflected to the third reflector 9, and then reflected by the third reflector 9 and enters through the side optical window of the low temperature thermostat 11, that is, it is incident on the sample of the device under test along the direction of the parallel magnetic field, and excites the sample, thereby realizing the excitation of the sample of the device under test by the incident light parallel magnetic field.

[0040] The spectral module filters the incident light from the sample module, switches the light path for collecting the emission signal, and outputs the measurement information corresponding to the optical path. Specifically, the spectral module includes at least a first achromatic lens 13, a switchable filter group 14, an adjustable attenuator group 15, a fourth reflector 16, a fifth reflector 17, a sixth reflector 18, a second achromatic lens 19, a third achromatic lens 20, a fourth achromatic lens 21, a scientific camera 22, a grating spectrometer 23, a first photomultiplier tube 24, a silicon photodiode 25, a transimpedance amplifier 26, a digital multimeter 27, and a fiber optic spectrometer 28.

[0041] Among them, the first achromatic lens 13 is used to collimate the light emission of the collimating device, the fourth reflector 16, the fifth reflector 17 and the sixth reflector 18 are used to switch the light emission collection path of the sample of the device under test, and the second achromatic lens 19, the third achromatic lens 20 and the fourth achromatic lens 21 are used to focus the light emission signal.

[0042] The first achromatic lens 13, the switchable filter group 14, the adjustable attenuator group 15, the fourth reflector 16, the fifth reflector 17, the sixth reflector 18, and the silicon photodiode 25 are sequentially arranged in the light collection path of the sample emission.

[0043] The switchable filter group 14 is a filter group that can switch between different transmission wavelengths, and the adjustable attenuator group 15 is an attenuator group with adjustable attenuation level. The switchable filter group 14 can filter the incident light entering the sample module, filtering out excessively strong excitation light that affects the sample's emission signal, and can also collect signals of specific wavelengths emitted at multiple wavelengths. The adjustable attenuator group 15 reduces the intensity of the emission signal to be measured to protect the subsequent detector.

[0044] The fourth reflector 16, the fifth reflector 17, and the sixth reflector 18 are all detachably installed in the spectral module. The second achromatic lens 19, the third achromatic lens 20, and the fourth achromatic lens 21 are respectively set in the reflected light paths of the fourth reflector 16, the fifth reflector 17, and the sixth reflector 18. The grating spectrometer 23 and the fiber optic spectrometer 28 are respectively fixed in the reflected light paths of the fourth reflector 16 and the sixth reflector 18.

[0045] When the fourth reflecting mirror 16 is added to the optical path, the light emission signal is reflected by the fourth reflecting mirror 16, focused by the second achromatic lens 19, and enters the grating spectrometer 23 to obtain a single wavelength light emission signal. Subsequently, the first photomultiplier tube 24 converts the optical signal intensity into an electrical signal to obtain spectral information.

[0046] After the fourth reflecting mirror 16 is removed from the optical path, the light emission signal will continue to advance. After being reflected by the fifth reflecting mirror 17, it will be focused by the fourth achromatic lens 21 and enter the scientific imaging camera 22 for sample imaging.

[0047] After the fourth reflector 16 and the fifth reflector 17 are removed from the optical path, the light emission signal will continue to advance. After being reflected by the sixth reflector 18, it will be focused by the third achromatic lens 20 and enter the fiber optic spectrometer 28. After the light signal is captured and measured by the fiber optic spectrometer 28, the emission spectrum is obtained.

[0048] When there are no reflectors in the light path, that is, when the fourth reflector 16, the fifth reflector 17 and the sixth reflector 18 are removed from the light path, the light emission signal will directly enter the silicon photodiode 25. The silicon photodiode 25 converts the light emission signal into a current signal, which is then amplified by the transimpedance current amplifier 26 and converted into a voltage signal, which is measured and recorded by the digital multimeter 27.

[0049] The timing module switches the optical path of the emission signal entering the spectral module and outputs transient emission information. Specifically, the timing module includes at least a second photomultiplier tube 29, a high-bandwidth amplifier unit 30, an oscilloscope 31, a single-photon counter 32, and a time-to-digital converter 33. The second photomultiplier tube 29 is a high-speed response photomultiplier tube. The emission signal entering the grating spectrometer 23 can be converted into a current signal by replacing the first photomultiplier tube 24 after the grating spectrometer 23 with the high-speed response second photomultiplier tube 29. The current signal is then amplified by the high-bandwidth amplifier unit 30 and converted into a voltage signal. The oscilloscope 31 measures the voltage signal to obtain the transient emission response of the device under test. The oscilloscope 31 can also measure the transient current response of the device by connecting it in series with the device circuit.

[0050] The emission signal entering the fiber optic spectrometer 28 can be transferred to a single-photon counter 32 by replacing the fiber. This counter measures the transient emission signal and converts it into a level signal. The level signal is then input to a time-to-digital converter 33. The synchronous output signal of the gigahertz signal generator 3 in the electro-excitation measurement module is also input to the time-to-digital converter 33 as a trigger signal. The time-to-digital converter 33 performs counting processing on the level signal to ultimately obtain the transient emission information.

[0051] Example 2: Measurement Method of Magnetic Field Effect of Temperature-Variable Steady-State and Transient Electroluminescent Devices The magnetic field effect measurement method of the present invention includes: The electrical excitation measurement module is controlled to switch the electrical excitation output mode. Preferably, the device excitation method is selected through software-controlled devices within the electrical excitation measurement module.

[0052] The equipment within the sample module is modified, the incident light path is switched, and the excitation method of the device under test sample is selected. Preferably, the first reflecting mirror 7 is installed or removed, the incident light path of the light source 6 is switched, and the vertical magnetic field or parallel magnetic field of the device under test sample is excited.

[0053] By changing the equipment within the spectral module, switching the output optical path, and altering the optical path, the test results of imaging, steady-state electroluminescence spectrum, electroluminescence intensity, or electroluminescence transient lifetime of the device under test sample are output. Preferably, the fourth reflector 16, the fifth reflector 17, or the sixth reflector 18 are installed or removed respectively to switch between different optical paths.

[0054] Example 3: Measurement of temperature-dependent steady-state electroluminescence and magnetic field effects of sample devices.

[0055] (1) Fix the sample device to the printed circuit board sample stage 12 with low-temperature resistant varnish, place the sample stage 12 into the constant temperature low-temperature instrument 11, and tighten the screws to fix the sample stage. Install the activated carbon box for adsorbing volatile gases attached to the sample chamber, cover the sample chamber and fix it with screws, and open the valve connecting the sample chamber to the vacuum pump attached to the low-temperature constant temperature instrument 11.

[0056] (2) The equipment is controlled by the corresponding computer control software. First, the vacuum pump attached to the low-temperature thermostat 11 is turned on to evacuate the sample chamber to a vacuum. When the vacuum degree reaches 10 -4 After maintaining the mBar temperature for one hour, turn on the matching helium compressor and the water chiller of the helium compressor to start cooling. After about 3 hours, the sample chamber temperature drops to the default set temperature of 5 K and remains stable.

[0057] (3) The sample device was electrically excited by the single-channel steady-state source table 1 in constant current mode using software control. First, the fourth reflector 16 was removed and the fifth reflector 17 was installed so that the light beam emitted by the device entered the scientific camera 22. The scientific camera 22 was used to image the device, and the optical path was adjusted so that the image was located in the center of the camera to meet the needs of subsequent experiments.

[0058] (4) Remove the fourth reflector 16, the fifth reflector 17, and the sixth reflector 18. The light beam emitted by the device enters the silicon photodiode 25. The light intensity of the device is obtained by reading the digital multimeter 27 through the software on the external computer. At this time, the wavelength range of the reading spectrum is adjusted by adjusting the switchable filter group 14 and the adjustable attenuation group 15, and the light intensity is adjusted to a suitable value to meet the requirements of subsequent spectral testing.

[0059] (5) Connect the SMA interface fiber to the fiber optic spectrometer 28 and install the sixth reflecting mirror 18. The light emitted by the sample device is collimated by the first achromatic lens 13, reflected by the sixth reflecting mirror 18, and then focused by the third achromatic lens 20. The light beam enters the spectrometer. At this time, the output voltage can be changed by controlling the single-channel steady-state source table 1 through software. The current-voltage characteristic curve of the device and the relationship between the electroluminescence spectrum and the device voltage are measured.

[0060] (6) The sixth reflector 18 is removed. At this time, the light beam emitted by the device enters the silicon photodiode 25, and the light signal is converted into a current signal. The current signal is amplified by the transimpedance amplifier 26 and converted into a voltage signal. Then, the voltage signal is read by the digital multimeter 27 to represent the light intensity of the device. Subsequently, the electromagnetic field 10 is controlled by software to perform a magnetic field sweep operation between -300 mT and 300 mT, and the relationship between the magnetic field and the light intensity, as well as the relationship between the magnetic field and the device current, is read by the software to obtain the magnetic field effect of the device's electroluminescence and the magnetic field effect of the current. The above test can obtain the steady-state spectrum of the device's electroluminescence and the magnetic field effect of electroluminescence and the magnetic field effect of the current at 5 K. The accuracy of the experimental results can also be improved by averaging the results of multiple tests.

[0061] (7) After the above test is completed, the electromagnetic field 10 is first controlled by the program to return the magnetic field to zero, and the single-channel source meter 1 also stops outputting. Finally, the constant temperature low temperature instrument 11 is controlled to change the temperature. When the temperature rises to the set value, the above steps are repeated to obtain the above data at different temperatures.

[0062] (8) After all tests are completed, turn off the helium compressor and water chiller attached to the constant temperature low temperature instrument, wait for 5 hours, and allow the temperature to rise naturally or turn on the thermocouple of the constant temperature low temperature instrument to heat up so that the sample chamber returns to room temperature.

[0063] (9) After the sample chamber of the constant temperature low temperature instrument returns to room temperature, open the vacuum valve of the sample chamber to break the vacuum state, open the sample chamber cover, loosen the screws that fix the sample stage, remove the device sample, then put the sample chamber cover back on and fix it with screws, use the software to shut down all instruments, then close the software, and finally turn off the power of all devices to complete all the required tests.

[0064] The test optical path diagram, as well as the temperature-dependent steady-state luminescence measurement results and the electroluminescence magnetic field effect results of the device, are shown below. Figure 2 As shown.

[0065] Example 4: Transient response of electroluminescence of sample device and measurement of magnetic field effect of electroluminescence in pulse mode.

[0066] (1) Fix the sample device to the printed circuit board sample stage 12 with low-temperature resistant adhesive, and place it in the constant temperature low-temperature instrument 11. Tighten the screws to fix the sample stage. Install the activated carbon box of the sample chamber, cover the sample chamber and fix it with screws. Open the valve connecting the sample chamber to the vacuum pump.

[0067] (2) The equipment is controlled by the corresponding computer control software. First, the vacuum pump attached to the low-temperature thermostat 11 is turned on to evacuate the sample chamber to a vacuum level of 10. -4 After mBar is completed, you can start testing.

[0068] (3) The device is electrically excited in pulse mode by using the dual-channel steady-state transient source table 2 controlled by software. The pulse width, duty cycle and pulse intensity can be adjusted according to experimental requirements. Then, the fourth reflector 16 is removed and the fifth reflector 17 is installed. The device is imaged by the scientific camera 22. The optical path is adjusted so that the image of the sample device is located at the center of the camera.

[0069] (4) Install the fourth reflecting mirror 16 and use the second achromatic lens 19 to focus the light beam emitted by the device. Then, the focused beam enters the grating spectrometer 23. At this time, the slit can be manually adjusted. Then, the software controls the grating spectrometer 23 and the first photomultiplier tube 24 to work together to read the emission spectrum of the device. At this time, the position of the grating in the grating spectrometer 23 can be controlled by the software to select the wavelength range of the component to be measured in the emission signal. After the wavelength range of the emission signal is selected, the first photomultiplier tube 24 is removed and the fast-response second photomultiplier tube 29 is installed to convert the light signal into a current signal. Then, a high-frequency wideband amplifier unit 30 is connected to the output terminal of the second photomultiplier tube 29 to amplify the current signal and convert it into a voltage signal. The voltage signal is read using an oscilloscope 31 to obtain the transient electroluminescence response of the device.

[0070] (5) After completing the transient electroluminescence response test of the device, the electromagnetic field 10 is controlled by software to perform a magnetic field sweep operation between -300 mT and 300 mT. The magnetic field strength and the voltage signal on the oscilloscope 31 are read by the software to obtain the relationship between the device's luminescence intensity and the magnetic field. Alternatively, the magnetic field strength of the electromagnetic field can be fixed, and multiple pulses can be performed using the dual-channel steady-state transient source table 2 to measure the average intensity of the device's luminescence under multiple pulses, thereby improving the accuracy of the experimental results. Then, the electromagnetic field strength is changed and the above operation is repeated to obtain the magnetic field effect of the device's electroluminescence in pulse mode.

[0071] (6) After completing all tests, use the software to shut down all equipment, as well as the helium compressor and water chiller attached to the constant temperature cryostat, and wait for 5 hours for the sample chamber to return to room temperature naturally.

[0072] (7) After the sample chamber of the constant temperature low temperature instrument returns to room temperature, open the vacuum valve of the sample chamber to break the vacuum state, open the sample chamber cover, loosen the screws that fix the sample stage, remove the device sample, then put the sample chamber cover back on and fix it with screws, use the software to shut down all instruments, then close the software, and finally turn off the power of all devices to complete all required tests.

[0073] The test optical path diagram, the transient response of electroluminescence, and the magnetic field effect results of electroluminescence in pulsed mode are shown in the figure below. Figure 3 As shown Example 5: Measurement of transient decay and magnetic field effect of temperature-dependent electroluminescence of sample device.

[0074] (1) Fix the sample device to be tested onto the printed circuit board sample stage 12 with low temperature resistant tape, and place it into the constant temperature low temperature instrument 11. Tighten the screws to fix the sample stage. Then, cover the sample chamber with the lid and fix it with screws. Open the valve connecting the sample chamber to the vacuum pump.

[0075] (2) The equipment is controlled by the corresponding computer control software. The vacuum system of the low-temperature thermostat 11 is turned on to evacuate the sample chamber to a vacuum. When the vacuum degree reaches 10... -4 After maintaining the temperature at mBar for one hour, the matching helium compressor and water chiller are turned on to begin cooling. The test can only begin after the sample chamber has cooled to 5 K and remained stable.

[0076] (3) Use software to control the gigahertz signal generator 3 to generate the pulse signal required for the experiment, and connect its output to the gigahertz power amplifier 4 to amplify the square wave signal. Then send the amplified signal to the device through the junction box 5.

[0077] (4) Install the fifth reflector 17, use the fourth achromatic lens to focus the light beam emitted by the device, and use a scientific camera to image the device. Adjust the optical path so that the device is imaged in the center of the camera.

[0078] (5) Disassemble the fifth reflector 17, install the sixth reflector 18, use the third achromatic lens 20 to focus the light emitted by the device into the optical fiber, connect the other end of the optical fiber to the single photon counter 32, and convert the photon signal into a level signal; at the same time, connect the synchronization signal of the electrical pulse generated by the gigahertz signal generator 3 to the time digital signal converter 33 to record the electrical pulse, connect the output signal of the single photon counter 32 to the time digital signal converter 33 to count the photons, and use a computer to perform time-correlated photon counting to obtain the transient decay data of the electroluminescence of the device.

[0079] (6) After completing the transient decay test of the electroluminescence of the device, a magnetic field of 300 mT was generated by controlling the electromagnetic field 10 with software. The above test process was then repeated to obtain the transient decay data of the electroluminescence of the device at 300 mT. Subsequently, the electromagnetic field 10 was controlled to generate a magnetic field of -300 mT, and the above test process was repeated to obtain the transient decay data of the electroluminescence of the device at -300 mT. The two results were averaged and compared with the transient decay data of the electroluminescence of the device when there was no external magnetic field to obtain the magnetic field effect of the transient decay process of the electroluminescence of the device.

[0080] (7) After completing the above test, turn off the output of the gigahertz signal generator 3, use the program to control the constant temperature low temperature instrument to raise the temperature, and repeat the above process after reaching the predetermined temperature to obtain the transient decay data of the device’s temperature-dependent electroluminescence.

[0081] (8) After completing all tests, use the software to shut down all equipment, as well as the helium compressor and water chiller attached to the constant temperature cryostat, and wait for 5 hours for the sample chamber to return to room temperature naturally.

[0082] (9) After the sample chamber of the cryostat returns to room temperature, open the vacuum valve of the sample chamber to break the vacuum, open the sample chamber cover, loosen the screws securing the sample stage, remove the device sample, then close the sample chamber cover again and secure it with screws. Use the software to shut down all instruments, then close the software, and finally turn off the power to all devices to complete all required tests. Test the optical path diagram, and measure the transient decay and magnetic field effect of temperature-dependent electroluminescence as follows: Figure 4 As shown.

[0083] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnetic field effect measurement system for a variable-temperature steady-state and transient electroluminescent device, characterized in that, The magnetic field effect measurement system includes at least an electro-excitation measurement module, a sample module, a spectral module, and a time module; The electro-excitation measurement module controls and adjusts the electro-excitation output mode, and the electro-excitation measurement module is connected to the sample module. The sample module includes at least a sample stage, a cryostat, an electromagnetic field, and a first, second, and third reflecting mirror for switching the incident light path. The first reflecting mirror is detachably installed inside the sample module, and the device under test sample is fixed in the sample stage of the cryostat. When the first reflector is disassembled, the incident light is reflected to the second reflector, so that the incident light is perpendicular to the magnetic field and excites the device under test sample. When the first reflector is installed, the incident light is reflected to the third reflector, so that the incident light is parallel to the magnetic field and excites the device under test sample. The spectral module filters the incident light from the sample module, switches the light path for collecting the emission signal, and outputs measurement information corresponding to the optical path. The measurement information includes the output of the imaging, steady-state electroluminescence spectrum, electroluminescence intensity, or electroluminescence transient lifetime test results of the device under test sample. The time module switches the optical path of the emission signal entering the spectral module and outputs transient emission information; The temperature range of the sample module is 5 K to 300 K, and the magnetic field strength varies continuously from -300 mT to 300 mT.

2. The magnetic field effect measurement system according to claim 1, characterized in that, The electro-excitation measurement module includes at least a light source, a single-channel steady-state source meter, a dual-channel steady-state and transient source meter, a gigahertz signal generator, a gigahertz power amplifier, and a junction box. One output of the gigahertz signal generator is connected to the gigahertz power amplifier, and the other output is connected to the time module. The electro-excitation measurement module is connected to the devices in the sample module through the junction box.

3. The magnetic field effect measurement system according to claim 1, characterized in that, The electromagnetic field is integrated with a low-temperature thermostat, the temperature range of which is 5 K to 300 K, and the magnetic field strength of the electromagnetic field continuously varies from -300 mT to 300 mT.

4. The magnetic field effect measurement system according to claim 1, characterized in that, The spectral module includes at least a switchable filter group, an adjustable attenuator group, four achromatic lenses, three mirrors for switching the light collection path of the sample emission from the device under test, a silicon photodiode, a grating spectrometer, and a fiber optic spectrometer. The grating spectrometer includes a first photomultiplier tube. The first achromatic lens, the switchable filter group, the adjustable attenuator group, the fourth mirror, the fifth mirror, the sixth mirror, and the silicon photodiode are sequentially arranged in the light collection path of the sample emission from the device under test. The fourth, fifth, and sixth mirrors are detachably mounted within the spectral module. The second, third, and fourth achromatic lenses are respectively arranged in the reflected light paths of the fourth, fifth, and sixth mirrors. The grating spectrometer and the fiber optic spectrometer are respectively fixed in the reflected light paths of the fourth and sixth mirrors.

5. The magnetic field effect measurement system according to claim 4, characterized in that, The first achromatic lens is used to collimate the light emitted by the collimating device, the second, third and fourth achromatic lenses are used to focus the light emitted signal, and the silicon photodiode is used to collect the light emitted signal when the fourth, fifth and sixth reflectors are all removed.

6. The magnetic field effect measurement system according to claim 4, characterized in that, The timing module includes at least a second photomultiplier tube and a single-photon counter. The second photomultiplier tube replaces the first photomultiplier tube of the grating spectrometer. After the second photomultiplier tube converts the emission signal into a current signal, the current signal is amplified by a high-frequency wideband amplifier unit and converted into a voltage signal. The voltage signal is then read by an oscilloscope to obtain the transient emission response. The single-photon counter replaces the fiber optic spectrometer, converts the emission signal into a level signal, and uses a time-to-digital converter to obtain the transient electroluminescence information of the device under test sample.

7. A method for measuring the magnetic field effect using a magnetic field effect measurement system for a variable-temperature steady-state and transient electroluminescent device according to any one of claims 1-6, characterized in that, The method for measuring magnetic field effects includes at least the following: Control the electro-excitation measurement module to switch the electro-excitation output mode; The equipment within the sample module is modified, the incident optical path is switched, and the excitation mode of the sample of the device under test is selected; By changing the equipment within the spectral module, switching the output optical path, and altering the optical path, the test results of imaging, steady-state electroluminescence spectrum, electroluminescence intensity, or electroluminescence transient lifetime of the device under test sample are output. The modification of the equipment within the sample module further includes installing or removing the first reflector.

8. The magnetic field effect measurement method according to claim 7, characterized in that, Modifying the equipment within the spectral module further includes: installing or removing the fourth, fifth, or sixth reflecting mirror respectively, and switching between different optical paths.

Images