Micro-led ac-dc comprehensive equivalent circuit model and component parameter extraction and fitting method

Abstract

The application discloses a Micro-LED AC-DC comprehensive equivalent circuit model and a component parameter fitting method thereof. The Micro-LED AC-DC comprehensive equivalent circuit model comprises an electric module and an electric-optical conversion module which are mutually decoupled; the electric module is used for representing DC IV, radio frequency impedance and S11 characteristics of the Micro-LED; the electric-optical conversion module is used for controlling light emission of a light-emitting area of the Micro-LED and representing S21 characteristics; the electric module comprises a dynamic active area resistor which is used for realizing fusion of a DC large signal and an AC small signal; the electric-optical conversion module is configured to be independently driven through a control signal of a controlled source; and the control signal of the controlled source comprises branch current flowing through the dynamic active area resistor in the electric module. The Micro-LED AC-DC comprehensive equivalent circuit model realizes unified modeling of the DC large signal characteristics and the AC small signal radio frequency characteristics, accurately represents the radio frequency impedance, the light-emitting area light emission characteristics, the S11 characteristics and the S21 characteristics of the Micro-LED in the same model, and improves modeling precision and circuit level simulation compatibility of the Micro-LED in a high-speed optical communication system.

Description

Technical Field

[0001] This invention relates to the field of micro light-emitting diodes, and in particular to a micro-LED AC / DC integrated equivalent circuit model and a method for extracting and fitting component parameters. Background Technology

[0002] With the development of 6G and the Internet of Things, visible light communication (VLC) and light fidelity technology (LiFi) have attracted much attention due to their advantages such as unlicensed spectrum, high transmission rate and no electromagnetic radiation. Micro-LED, due to its extremely small size (typically less than 100 micrometers), smaller RC time constant and shorter recombination carrier lifetime, has extremely high modulation bandwidth and has become the core light source of high-speed visible light communication systems.

[0003] In the development of high-speed optical communication systems, establishing an accurate Micro-LED equivalent circuit model (i.e., a compact model or SPICE model) is crucial for achieving efficient co-design of external driving circuits (such as modulators and driver chips) and Micro-LED chips. This is not only a bridge connecting the physical characteristics of devices with system-level circuit simulation, but also the foundation for evaluating the signal integrity of high-frequency radio frequency (RF) communication links and designing impedance matching networks. However, current Micro-LED optical communication models still have significant shortcomings in accuracy, versatility, and simulation compatibility.

[0004] In response to the shortcomings of current optical communication equivalent circuit models, such as the inability to naturally synthesize AC and DC signals, inaccurate fitting of S-parameters and phase under different injection characteristics, and complex parameter extraction processes, the industry urgently needs a Micro-LED integrated RF model that is highly accurate, fast, convenient, and can be directly placed in the circuit for simulation. Summary of the Invention

[0005] The present invention provides a Micro-LED AC / DC integrated equivalent circuit model and a method for extracting and fitting component parameters to solve at least one of the above-mentioned technical problems.

[0006] An embodiment of the present invention provides a Micro-LED AC / DC integrated equivalent circuit model comprising a decoupled electrical module and an electro-optical conversion module; the electrical module is used to characterize the DC IV electrical characteristics, RF impedance, and S11 characteristics of the Micro-LED, and the electro-optical conversion module is used to control the light emission of the light-emitting area of ​​the Micro-LED and characterize the S21 characteristics; the electrical module includes a dynamic active region resistor, which is used to realize the fusion of large DC signals and small AC signals; the electro-optical conversion module is configured to be independently driven by a control signal from a controlled source, the control signal of the controlled source including the branch current flowing through the dynamic active region resistor in the electrical module.

[0007] The aforementioned Micro-LED AC / DC integrated equivalent circuit model includes a decoupled electrical module and an electro-optical conversion module. The electro-optical conversion module is driven by the branch current flowing through the dynamic active region resistor. The dynamic active region resistor achieves unified modeling of DC large-signal characteristics and AC small-signal RF characteristics. It can accurately characterize the DC IV characteristics, RF impedance, and S11 characteristics of Micro-LED, as well as the emission of the light-emitting region of Micro-LED and characterize the S21 characteristics in the same model, thereby improving the modeling accuracy and circuit-level simulation compatibility of Micro-LED in high-speed optical communication systems.

[0008] In some embodiments, the electrical module further includes a series inductor, pad parasitic capacitance, substrate resistance, series resistance, and junction capacitance; The series inductance, the pad parasitic capacitance, and the substrate resistance are used to characterize the packaging and wiring parasitic effects of the Micro-LED. The series resistance, the junction capacitance, and the dynamic active region resistance are used to characterize the device physical characteristics of the Micro-LED. The dynamic active region resistance is connected in parallel with the junction capacitance.

[0009] In some implementations, the parameters of the dynamic active region resistance are obtained through measured electrical data of the Micro-LED.

[0010] In some embodiments, the electro-optic conversion module has multi-pole and zero-point dynamic response characteristics. The electro-optic conversion module includes an energy storage capacitor, an escape capacitor, a non-radiative recombination loss resistor, and an in-well transport loss branch. The in-well transport loss branch includes a first resistor and a first capacitor connected in parallel. The energy storage capacitor is used to control the carrier relaxation time, and the escape capacitor is used to control the photon escape time.

[0011] In some implementations, the branch current is used to characterize the effective current injected into the active region of the quantum well.

[0012] In some implementations, the Micro-LED AC / DC integrated equivalent circuit model integrates a multi-dimensional lookup table matrix. This multi-dimensional lookup table matrix is ​​used during circuit simulation to allow the Micro-LED AC / DC integrated equivalent circuit model to dynamically call electrical and optical component parameters corresponding to different conditions using a lookup table method.

[0013] The component parameter extraction and fitting method for a Micro-LED AC / DC integrated equivalent circuit model provided by the embodiments of the present invention includes: The measured electrical data of the Micro-LED under different test conditions are obtained, including DC characteristic data and AC small signal data; The DC characteristic data is processed to obtain the static differential resistance, and the physical optimization boundary of the dynamic active region resistance is determined based on the static differential resistance. Within the physical optimization boundary, the AC small-signal data is used as the objective function. The machine learning algorithm is used to iteratively optimize the component parameters in the Micro-LED AC / DC integrated equivalent circuit model and output the optimal component parameter matrix under different test conditions. The Micro-LED AC / DC equivalent circuit model is established based on the optimal component parameter matrix.

[0014] In some embodiments, the component parameter extraction and fitting method further includes; The established Micro-LED AC / DC integrated equivalent circuit model was verified by AC / DC fusion simulation.

[0015] In some implementations, the physical optimization boundary is ±5% of the value corresponding to the static differential resistor.

[0016] In some implementations, the AC small-signal data includes amplitude data and expanded phase data of parameter S11, and amplitude data and expanded phase data of parameter S21.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein: Figure 1 This is a theoretical structural diagram of the Micro-LED optical communication model according to an embodiment of the present invention; Figure 2 This is a circuit diagram of the Micro-LED AC / DC integrated equivalent circuit model according to an embodiment of the present invention; Figure 3 This is a solution diagram of the static differential resistance according to an embodiment of the present invention; Figure 4 and Figure 5 This is a flowchart illustrating the component parameter extraction and fitting method for the Micro-LED AC / DC integrated equivalent circuit model according to an embodiment of the present invention. Figures 6 to 8 This is a verification result diagram of the component parameter extraction and fitting method of the Micro-LED AC / DC integrated equivalent circuit model according to the embodiments of the present invention. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of the present invention, and should not be construed as limiting the embodiments of the present invention.

[0020] With the development of 6G and the Internet of Things, visible light communication (VLC) and light fidelity technology (LiFi) have attracted much attention due to their advantages such as unlicensed spectrum, high transmission rate and no electromagnetic radiation. Micro-LED, due to its extremely small size (typically less than 100 micrometers), smaller RC time constant and shorter recombination carrier lifetime, has extremely high modulation bandwidth and has become the core light source of high-speed visible light communication systems.

[0021] In the development of high-speed optical communication systems, establishing an accurate Micro-LED equivalent circuit model (i.e., a compact model or SPICE model) is crucial for achieving efficient co-design of external driving circuits (such as modulators and driver chips) and Micro-LED chips. This is not only a bridge connecting the physical characteristics of devices with system-level circuit simulation, but also the foundation for evaluating the signal integrity of high-frequency radio frequency (RF) communication links and designing impedance matching networks.

[0022] However, current Micro-LED optical communication models still have significant shortcomings in terms of accuracy, versatility, and simulation compatibility. First, existing models typically separate the DC large-signal characteristics from the AC small-signal RF characteristics. During simulation, diode models are often used in DC mode, and then manually replaced with fixed resistors in AC communication mode. This fails to perfectly integrate AC and DC behavior within the same circuit simulation model, resulting in an inability to realistically and consistently reflect the dynamic operating state of the device under the superposition of complex large-signal driving and small-signal modulation. Second, traditional equivalent circuit models lack sufficient fitting accuracy for high-frequency RF parameters (especially S11 and S21). They often only focus on single-pole attenuation of the amplitude-frequency characteristics, failing to accurately characterize and fit phase change characteristics at high frequencies. They also struggle to reflect the recombination of carriers injected into the active region and the recombination behavior of multiple poles / zeros, such as relaxation times with different lifetimes (e.g., trap energy storage and photon escape). Finally, as the complexity of the RF equivalent model increases, multidimensional physical parameters (such as package parasitic parameters and intrinsic junction capacitance, quantum well resistance, etc.) are severely coupled. The traditional parameter extraction process is too cumbersome, resulting in difficulty in parameter fitting, long time consumption, and easy deviation from the real physical boundary conditions, making it difficult to call in the real circuit simulation process.

[0023] In response to the shortcomings of current optical communication equivalent circuit models, such as the inability to naturally synthesize AC and DC signals, inaccurate fitting of S-parameters and phase under different injection characteristics, and complex parameter extraction processes, the industry urgently needs a Micro-LED integrated RF model that is highly accurate, fast, convenient, and can be directly placed in the circuit for simulation.

[0024] Therefore, please combine Figures 1 to 3 The present invention provides a Micro-LED AC / DC integrated equivalent circuit model comprising a decoupled electrical module and an electro-optical conversion module. The electrical module is used to characterize the radio frequency impedance and S11 characteristics of the Micro-LED, and the electro-optical conversion module is used to control the light emission of the light-emitting area of ​​the Micro-LED and characterize the S21 characteristics. The electrical module includes a dynamic active region resistor, which is used to realize the fusion of large DC signals and small AC signals. The electro-optical conversion module is configured to be independently driven by a control signal from a controlled source, and the control signal from the controlled source includes the branch current flowing through the dynamic active region resistor in the electrical module.

[0025] The aforementioned Micro-LED AC / DC integrated equivalent circuit model includes a decoupled electrical module and an electro-optical conversion module. The electro-optical conversion module is driven by the branch current flowing through the dynamic active region resistor. The dynamic active region resistor achieves unified modeling of DC large-signal characteristics and AC small-signal RF characteristics. It can accurately characterize the RF impedance and S11 characteristics of Micro-LED and the emission and S21 characteristics of Micro-LED in the same model, thereby improving the modeling accuracy and circuit-level simulation compatibility of Micro-LED in high-speed optical communication systems.

[0026] Specifically, in conjunction with the actual physical structure of Micro-LEDs (such as...) Figure 1 The theoretical structure diagram of the Micro-LED optical communication model shown is illustrated, along with the analysis of the carrier recombination luminescence mechanism, establishing a theoretical structure as follows: Figure 2 The Micro-LED AC / DC integrated equivalent circuit model is shown. The Micro-LED AC / DC integrated equivalent circuit model is divided into two parts: the electrical module (EE module) and the electro-optical conversion module (EO module).

[0027] The electrical module characterizes the DC IV electrical characteristics, RF impedance, and S11 characteristics of Micro-LEDs. It describes the electrical response behavior of electrical signals injected into the Micro-LED from an external circuit, including the Micro-LED's DC current-voltage (IV) characteristics, equivalent impedance at different frequencies, and input signal reflection, thus reflecting the electrical matching characteristics of the Micro-LED's input. The electro-optic conversion module controls the emission of light from the Micro-LED's light-emitting region and characterizes the S21 characteristics. It generates a corresponding light emission response based on the current injected into the active region and participating in recombination, describing the transmission process and frequency response characteristics of the input electrical signal after electro-optic conversion to form an optical output signal. In other words, the electrical module primarily reflects the electrical behavior of electrical signals entering the Micro-LED, while the electro-optic conversion module reflects the transmission behavior of the electrical signal being converted into an optical signal inside the Micro-LED.

[0028] The electrical module includes a dynamic active region resistor, Rrec, whose equivalent resistance varies with the operating point of the Micro-LED. Under DC large-signal conditions, Rrec exhibits the large-signal nonlinear volt-ampere (IV) characteristic of a standard diode, used to determine the true DC operating state. Under AC small-signal conditions, Rrec is equivalent to a differential resistance obtained by differentiating the IV characteristic, used to describe the incremental response characteristics during high-frequency modulation. Therefore, Rrec can simultaneously characterize both DC conduction behavior and AC RF response, achieving unified modeling of DC large-signal characteristics and AC small-signal characteristics, i.e., realizing the fusion of AC and DC behavior.

[0029] The electro-optic conversion module is independently driven by a control signal from a controlled source. This means that the luminescence response of the electro-optic conversion module is determined by the control signal from the controlled source. The control signal includes the branch current Irec flowing through the dynamic active region resistor in the module. This current corresponds to the current component that is actually injected into the active region of the Micro-LED and participates in carrier recombination. Micro-LED luminescence originates from the radiative recombination process of carriers in the active region. Using Irec as the control signal from the controlled source allows the electro-optic conversion module to accurately reflect the physical mechanism of current-driven luminescence.

[0030] It should be noted that the decoupling of the electrical module and the electro-optical conversion module in this embodiment refers to their separation at the functional and modeling levels. The electrical module reflects the purely electrical behavior of the Micro-LED and describes the impedance characteristics of carrier injection into the Micro-LED; the electro-optical conversion module reflects the light emission process of the Micro-LED and is responsible for characterizing the light output response under electrical signal control. This invention extracts the branch current flowing through the dynamic active region resistor from the electrical module as a control signal to drive the controlled source of the electro-optical conversion module, making the light emission response determined by Irec. The electrical module is responsible for generating Irec, and the electro-optical conversion module responds to Irec without influencing the electrical module in the opposite direction, thereby achieving functional separation between electrical modeling and light emission modeling. In this embodiment of the invention, the electrical and light emission parts have clear boundaries and their parameters are not mixed, thus achieving mutual decoupling between the electrical module and the electro-optical conversion module.

[0031] In some implementations, please refer to Figure 1 and Figure 2 The electrical module also includes series inductors, pad parasitic capacitance, substrate resistance, series resistance, and junction capacitance; Series inductance, pad parasitic capacitance, and substrate resistance are used to characterize the packaging and wiring parasitic effects of Micro-LEDs. Series resistance, junction capacitance, and dynamic active region resistance are used to characterize the device physical characteristics of Micro-LEDs. The dynamic active region resistance is connected in parallel with the junction capacitance.

[0032] Specifically, in Figure 1 In the diagram, the central stacked structure corresponds to the multiple quantum well (MQW) active region of a Micro-LED, which is the core location for carrier injection and radiative recombination. Electrically equivalently, the MQW region consists of the junction capacitance Cj and the dynamic active region resistance Rrec.

[0033] Outside the active region, the device current path includes a series resistor Rs, which characterizes the ohmic loss effects of the electrode contacts, the current spreading layer, and the semiconductor material itself. Simultaneously, due to the presence of the Micro-LED chip, substrate, and pad structure, the device forms a parasitic coupling path to ground, which can be equivalently represented as a parallel branch consisting of the pad parasitic capacitance Cp and the substrate resistance Rsub, used to describe the substrate leakage path and high-frequency parasitic coupling effects.

[0034] During actual testing and driving, current is injected into the device through the P electrode and connected to the external driving circuit via the bonding wires. Since the bonding wires and package traces inevitably introduce electromagnetic energy storage effects, this part can be equivalent to a series inductance Ls, used to characterize the parasitic inductance effect generated by the package interconnect structure under high-frequency conditions.

[0035] exist Figure 2In the diagram, the series inductance Ls characterizes the parasitic inductance effect generated by the package leads and interconnect traces under high-frequency conditions. This parasitic inductance affects the input impedance of the Micro-LED as the frequency increases. The pad parasitic capacitance Cp characterizes the parasitic coupling capacitance formed between the chip pads and external electrodes. The substrate resistance Rsub describes the energy loss and resistance effect caused by the diffusion and transport of current in the substrate material. In summary, the series inductance, pad parasitic capacitance, and substrate resistance mainly reflect the external parasitic parameters introduced into the Micro-LED's packaging and interconnect structure, thus enabling the electrical module to truly reflect the actual input characteristics of the Micro-LED under RF conditions.

[0036] Series resistance Rs, junction capacitance Cj, and dynamic active region resistance Rrec are used to characterize the physical properties of Micro-LED devices. Specifically, series resistance Rs reflects ohmic losses in the electrode contacts, current spread layer, and semiconductor material; junction capacitance Cj describes the charge storage effect in the depletion region of the PN junction under varying bias conditions; and dynamic active region resistance Rrec characterizes the conductivity characteristics corresponding to the carrier recombination process in the active region and reflects the dynamic response behavior under different injection conditions as the operating point changes.

[0037] Furthermore, it should be noted that in actual Micro-LED devices, the current transport path typically includes both contact resistance and bulk resistance, which are connected in series in the current direction and exhibit a uniform voltage drop characteristic. Therefore, in this embodiment, the contact resistance and bulk resistance are equivalently combined and uniformly modeled as a series resistance Rs to reduce parameter redundancy and improve the stability of parameter extraction, while maintaining consistency with actual electrical behavior.

[0038] Similarly, the PN junction region contains both depletion layer capacitance and diffusion capacitance. These two types of capacitance are spatially continuous and jointly participate in the charge storage process, exhibiting an equivalent total capacitance response under small-signal radio frequency conditions. Therefore, this embodiment equivalently combines the depletion layer capacitance and diffusion capacitance, uniformly representing them as junction capacitance Cj, thereby simplifying the structure without changing the physical meaning of the Micro-LED device.

[0039] In some implementations, please refer to Figure 3 The parameters of the dynamic active region resistance are obtained through measured electrical data from Micro-LEDs.

[0040] Specifically, the parameters of the dynamic active region resistance are determined using measured electrical data from the Micro-LED, which can improve the consistency between the integrated AC / DC equivalent circuit model of the Micro-LED and the physical characteristics of the actual device. In one embodiment, the measured electrical data of the Micro-LED includes DC characteristic data, which is the current-voltage (IV) characteristic curve measured by the Micro-LED device.

[0041] In some implementations, please refer to Figure 2 The electro-optic conversion module has multi-pole and zero-point dynamic response characteristics. The electro-optic conversion module includes an energy storage capacitor, an escape capacitor, a non-radiative recombination loss resistor, and an in-well transport loss branch. The in-well transport loss branch includes a first resistor and a first capacitor connected in parallel. The energy storage capacitor is used to control the carrier relaxation time, and the escape capacitor is used to control the photon escape time.

[0042] Specifically, the energy storage capacitor C1 can characterize the storage effect of charge carriers in the active region of the quantum well. When current is injected, the charge carriers accumulate in the active region and participate in radiative recombination after undergoing a certain relaxation process. Therefore, the energy storage capacitor can simulate the time delay generated during the establishment and release of charge carriers, that is, control the relaxation time of charge carriers.

[0043] The escape capacitance C2 can characterize the dynamic process of photons propagating outward from the active region after being generated inside the Micro-LED and eventually escaping from the Micro-LED. Since there is an escape time from photon generation to output, this process can be equivalent to energy storage and release behavior with a time constant. By setting the escape capacitance to model the photon escape process, the delay characteristics in the light output response can be reflected.

[0044] The nonradiative recombination loss resistance R2 can describe the energy loss generated by charge carriers through nonradiative paths during recombination.

[0045] The transport loss branch inside the quantum well includes a first resistor R1 and a first capacitor Ct. The branch composed of R1 and Ct is used to simulate the energy loss and dynamic delay effect generated during the movement of charge carriers inside the quantum well.

[0046] The multi-pole network composed of energy storage capacitor C1, escape capacitor C2, and non-radiative composite loss resistor R2 overcomes the limitations of traditional single-pole low-pass models on the dynamic behavior of Micro-LEDs. This allows the model to accurately reproduce the amplitude-frequency convexity characteristics and pole decay behavior in the high-frequency region, thereby improving the model's fitting accuracy. Simultaneously, a zero-point control capacitor Ct is introduced to compensate for the phase advance and response enhancement effects of high-bandwidth Micro-LEDs in the ultra-high frequency range, achieving effective modeling of high-frequency zero-point characteristics and further improving the model's fitting accuracy.

[0047] In some implementations, please refer to Figure 1 and Figure 2 The branch current is used to characterize the effective current injected into the active region of the quantum well.

[0048] Specifically, branch current is used to characterize the effective current injected into the active region of the quantum well. Branch current refers to the current component separated from the total injected current in the equivalent circuit that actually flows through the active region and participates in the carrier recombination process. Since the light emission behavior in Micro-LEDs is determined by the carriers entering the quantum well and undergoing recombination, and there is still current shunted through parasitic paths in Micro-LED devices, the total input current cannot accurately reflect the true light emission driving capability. By extracting the branch current flowing through the dynamic active region resistance, the effective injected current participating in radiative recombination can be effectively characterized, enabling the electro-optic conversion process to be modeled based on the actual recombination current, thus improving the physical accuracy of the model and the consistency of the simulation.

[0049] In some implementations, the Micro-LED AC / DC integrated equivalent circuit model integrates a multi-dimensional lookup table matrix. This multi-dimensional lookup table matrix is ​​used during circuit simulation to allow the Micro-LED AC / DC integrated equivalent circuit model to dynamically call the electrical and optical component parameters corresponding to different conditions through a lookup table method.

[0050] The above implementation method makes the Micro-LED AC / DC integrated equivalent circuit model more universal, compatible and valuable for secondary development.

[0051] Specifically, the multidimensional lookup table (LUT) is used to store the electrical and optical component parameters of Micro-LEDs under different conditions. By testing or extracting parameters of Micro-LEDs under different conditions, the correspondence between electrical and optical component parameters as they change under different conditions is pre-established and recorded in the form of a multidimensional data table.

[0052] The integrated AC / DC equivalent circuit model of a Micro-LED can automatically index a multi-dimensional lookup table matrix based on different simulation conditions, thereby retrieving parameter values ​​that match those conditions and dynamically updating the component parameters in the electrical and electro-optical conversion modules. Optionally, the conditions include, but are not limited to, the size of the Micro-LED, its emission wavelength, injection current density, and temperature.

[0053] It should be noted that, Figure 2In the equivalent circuit model of Micro-LED AC / DC, a standard impedance Z0 is included. The standard impedance Z0 is an inherent configuration parameter of the optical communication test equipment. In circuit simulation environments, conventional simulation software (such as Cadence) usually uses an ideal voltage source as the excitation source and does not include the standard impedance condition by default. Therefore, by setting Z0, the simulation results can equivalently reproduce the characteristics reflected by the device during actual testing under ideal excitation conditions.

[0054] Please see Figure 4 and Figure 5 The component parameter extraction and fitting method for a Micro-LED AC / DC integrated equivalent circuit model provided by the embodiments of the present invention includes: Obtain measured electrical data of Micro-LED under different test conditions. The measured electrical data includes DC characteristic data and AC small signal data. The DC characteristic data is processed to obtain the static differential resistance, and the physical optimization boundary of the dynamic active region resistance is determined based on the static differential resistance. Within the physical optimization boundary, AC small-signal data is used as the objective function. Machine learning algorithms are used to iteratively optimize the component parameters in the Micro-LED AC / DC integrated equivalent circuit model and output the optimal component parameter matrix under different test conditions. A comprehensive AC / DC equivalent circuit model for Micro-LEDs is established based on the optimal component parameter matrix.

[0055] Specifically, electrical tests are performed on Micro-LED devices under different test conditions to obtain their DC characteristic data and AC small-signal data. The DC characteristic data is processed, such as by differentiation, to calculate the static differential resistance. Based on the static differential resistance, the range of values ​​for the dynamic active region resistance is determined, thereby determining the physical optimization boundary.

[0056] Under physical optimization boundary constraints, AC small-signal test data is used as the objective function for fitting. A machine learning algorithm iteratively optimizes the electrical and optical component parameters in the Micro-LED AC / DC integrated equivalent circuit model, outputting the optimal component parameter matrix under different test conditions. The machine learning algorithm may include at least one of differential evolution algorithm and local fine-tuning algorithm.

[0057] Next, a Micro-LED AC / DC integrated equivalent circuit model is established based on the optimal component parameter matrix, so that the Micro-LED AC / DC integrated equivalent circuit model can accurately characterize the physical characteristics of Micro-LED under different conditions by parameter calling.

[0058] It should be noted that the above explanation of the implementation method and beneficial effects of the Micro-LED AC / DC integrated equivalent circuit model also applies to the component parameter extraction and fitting method of the Micro-LED AC / DC integrated equivalent circuit model in this implementation method. To avoid redundancy, it will not be elaborated in detail here.

[0059] Optionally, test conditions include, but are not limited to, the size of the Micro-LED, the emission wavelength, the injection current density, and the temperature.

[0060] It should be noted that in some examples, the DC characteristic data is a complete coverage up to 2000 A / cm. 2 The IV (current-voltage) characteristic curve of the current density is used to define the operating range of the device and to derive its derivative; the AC small-signal data consists of wideband S11 (return loss) and S21 (forward propagation) parameters measured using a vector network analyzer (VNA). To construct an accurate and universally applicable integrated AC / DC equivalent circuit model for Micro-LEDs, the test data should cover at least three sets of different bias current densities (e.g., 50 A / cm²). 2 100A / cm 2 2000A / cm 2 ).

[0061] In some implementations, please refer to Figures 4 to 8 The methods for extracting and fitting component parameters also include; The established Micro-LED AC / DC integrated equivalent circuit model was verified by AC / DC fusion simulation.

[0062] Specifically, a Micro-LED AC / DC integrated equivalent circuit model, incorporating a multi-dimensional lookup table matrix, is imported into the simulation software. In DC simulation mode, the dynamic active region resistor Rrec is configured to activate the large-signal equivalent model while simultaneously disabling the AC response path of the electro-optic conversion module, thereby achieving simulation verification of the Micro-LED's DC operating characteristics. In AC simulation mode, the model, based on the current operating point, retrieves the corresponding AC small-signal Rrec resistance value from the multi-dimensional lookup table matrix and simultaneously activates the controlled-source-driven electro-optic conversion module to characterize the carrier dynamic recombination behavior and photoelectric modulation response, thus achieving... Figure 6 The automatic seamless switching between DC and AC was verified.

[0063] Please combine Figure 7 and Figure 8 Simulation results show that the Micro-LED AC / DC integrated equivalent circuit model established in this invention has a high degree of consistency with the measured electrical data. For example... Figure 7As shown, in the high-frequency phase fitting of the reflection parameter S11 and the transmission parameter S21, the goodness-of-fit R² of this model is greater than 0.99, significantly reducing the phase distortion problem that occurs in the high-frequency region of the traditional equivalent model. Furthermore, as... Figure 8 As shown, under different current density injection conditions ranging from 50 A / cm² to 2000 A / cm², the goodness of fit R² of the decay curve of the S21 parameter of this model is greater than 0.92, indicating that this model is not limited by a single bias condition and can maintain stable modeling accuracy over a wide operating range.

[0064] Optionally, the simulation software includes, but is not limited to, simulation platforms that support standard SPICE netlists, such as Ngspice, HSPICE, ADS (Advanced Design System), or Cadence.

[0065] In some implementations, the physical optimization boundary is ±5% of the value corresponding to the static differential resistor.

[0066] Specifically, since the dynamic active region resistance Rrec essentially reflects the recombination behavior of charge carriers, its value should be subject to the physical constraints of the actual device. Therefore, the value of the static differential resistance is used as the central reference value, and a physical optimization boundary is set within ±5% of it. This ensures that the machine learning or iterative optimization process always proceeds within the range that conforms to the actual physical laws of the device, thereby reducing the occurrence of mathematically fitted but physically meaningless results and improving the physical credibility of the model.

[0067] In some cases, the physical optimization boundary is -5%, -4%, -3%, -2%, -1%, 0%, 1%, 2%, 3%, 4%, 5% of the value corresponding to the static differential resistor, or other values ​​that are greater than or equal to -5% and less than or equal to 5%.

[0068] In some implementations, the AC small-signal data includes amplitude data and expanded phase data of parameter S11, and amplitude data and expanded phase data of parameter S21.

[0069] Specifically, the amplitude data of parameter S11 reflects the change in reflection intensity of the input signal at different frequencies, while its expanded phase data is used to describe the phase delay and frequency-dependent dynamic response behavior generated during the propagation of the signal inside the Micro-LED; the amplitude data of parameter S21 reflects the attenuation characteristics of electro-optic transmission gain with frequency, while its expanded phase data is used to reflect the time delay and multi-time constant coupling effect during the electro-optic conversion process.

[0070] By simultaneously introducing amplitude data and expanded phase data as the fitting target for AC small signals, the model can not only accurately fit the amplitude-frequency characteristics of the frequency response, but also accurately characterize the phase change law under high-frequency conditions, thereby improving the characterization accuracy of the Micro-LED AC / DC integrated equivalent circuit model for actual radio frequency optical communication behavior.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more steps for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0073] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, combinations, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A Micro-LED AC / DC integrated equivalent circuit model, characterized in that, The device includes a decoupled electrical module and an electro-optical conversion module. The electrical module is used to characterize the DC IV electrical characteristics, RF impedance, and S11 characteristics of the Micro-LED. The electro-optical conversion module is used to control the light emission of the light-emitting area of ​​the Micro-LED and characterize the S21 characteristics. The electrical module includes a dynamic active region resistor, which is used to achieve the fusion of large DC signals and small AC signals. The electro-optical conversion module is configured to be independently driven by a control signal from a controlled source. The control signal from the controlled source includes the branch current flowing through the dynamic active region resistor in the electrical module.

2. The Micro-LED AC / DC equivalent circuit model according to claim 1, characterized in that, The electrical module also includes a series inductor, pad parasitic capacitance, substrate resistance, series resistance, and junction capacitance; The series inductance, the pad parasitic capacitance, and the substrate resistance are used to characterize the packaging and wiring parasitic effects of the Micro-LED. The series resistance, the junction capacitance, and the dynamic active region resistance are used to characterize the device physical characteristics of the Micro-LED. The dynamic active region resistance is connected in parallel with the junction capacitance.

3. The Micro-LED AC / DC equivalent circuit model according to claim 1, characterized in that, The parameters of the dynamic active region resistance are obtained through measured electrical data of the Micro-LED.

4. The Micro-LED AC / DC equivalent circuit model according to claim 1, characterized in that, The electro-optic conversion module has multi-pole and zero-point dynamic response characteristics. The electro-optic conversion module includes an energy storage capacitor, an escape capacitor, a non-radiative recombination loss resistor, and an in-well transport loss branch. The in-well transport loss branch includes a first resistor and a first capacitor connected in parallel. The energy storage capacitor is used to control the carrier relaxation time, and the escape capacitor is used to control the photon escape time.

5. The Micro-LED AC / DC equivalent circuit model according to claim 1, characterized in that, The branch current is used to characterize the effective current injected into the active region of the quantum well.

6. The Micro-LED AC / DC equivalent circuit model according to claim 1, characterized in that, The Micro-LED AC / DC integrated equivalent circuit model integrates a multi-dimensional lookup table matrix. This multi-dimensional lookup table matrix is ​​used during circuit simulation to allow the Micro-LED AC / DC integrated equivalent circuit model to dynamically call the electrical and optical component parameters corresponding to different conditions through a lookup table method.

7. A method for extracting and fitting component parameters of a Micro-LED AC / DC integrated equivalent circuit model, characterized in that, include: The measured electrical data of the Micro-LED under different test conditions are obtained, including DC characteristic data and AC small signal data; The DC characteristic data is processed to obtain the static differential resistance, and the physical optimization boundary of the dynamic active region resistance is determined based on the static differential resistance. Within the physical optimization boundary, the AC small-signal data is used as the objective function. The machine learning algorithm is used to iteratively optimize the component parameters in the Micro-LED AC / DC integrated equivalent circuit model and output the optimal component parameter matrix under different test conditions. The Micro-LED AC / DC equivalent circuit model is established based on the optimal component parameter matrix.

8. The component parameter extraction and fitting method according to claim 7, characterized in that, The component parameter extraction and fitting method also includes; The established Micro-LED AC / DC integrated equivalent circuit model was verified by AC / DC fusion simulation.

9. The component parameter extraction and fitting method according to claim 7, characterized in that, The physical optimization boundary is ±5% of the value of the static differential resistor.

10. The component parameter extraction and fitting method according to claim 7, characterized in that, The AC small-signal data includes the amplitude data and expanded phase data of parameter S11, and the amplitude data and expanded phase data of parameter S21.

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