KR20210129568A - Simulation apparatus and method for OLED module - Google Patents

Abstract

The present invention relates to a simulation apparatus for an OLED module and a simulation method thereof and, more specifically, to a simulation apparatus for an OLED module, which supports calculation of a current generated when voltage is applied to an OLED module through numerical analysis based on parameter values specified by a user for materials forming the OLED module to support design of the OLED module, and a simulation method thereof. According to the present invention, by providing convenience for solving a Poisson equation and a continuity equation at once by using pdepe, which is a MATLAB built-in function, while providing a simulator in which a user can directly designate layers and parameter values for an OLED module to be designed, the method can reduce cost, simplify a simulation calculation process, and ensure easy accessibility for users in comparison with existing simulators. In addition, the method provides an effect of supporting design of a multi-layer OLED module capable of emitting light at a relatively low voltage with high accuracy to improve a low efficiency generated by increasing voltage. The method comprises a receiving step, an initial value calculation step, a function application step, a determination step, and a current density calculation step.

Description

Simulation apparatus and method for OLED module

The present invention relates to a simulation apparatus and method for an OLED module, and more specifically, a current generated when a voltage is applied to an OLED module through numerical analysis based on a parameter value specified by a user for a material constituting the OLED module. It relates to a simulation apparatus and method for an OLED module that supports the design of the OLED module by supporting the calculation.

OLED, which dominates the market share as a next-generation display, is widely used not only in large displays, but also in TVs and mobiles, and simulation programs for developing them are currently commercialized.

Among the various structures constituting OLED, multilayer OLED including bilayer (double-layer) OLED has been proven through many studies that it shows remarkable advantages in brightness, efficiency, and thickness that are superior to existing displays. Due to the heterojunction caused by the difference in energy bandgap between each material constituting the multilayer OLED, the recombination phenomenon occurs due to the movement of electrons and holes that occur when voltage is applied. Occurs. As a result of this phenomenon, excitons generated as a result fall to low energy, and what is generated is luminance.

Predicting the results before designing directly using a simulation program is a necessary pre-work in terms of time and cost efficiency for display production.

However, the reality is that the existing commercialized program is difficult to use for students or the general public unless it is used by a related company, as well as the cost of purchasing a license is expensive.

Korean Patent No. 10-0767732

The present invention provides a simulator for an OLED module by utilizing a matlab program, thereby providing a simulator that is relatively easy to use or access and does not have an expensive expenditure burden to use in terms of cost, as well as a simulator for designing an existing OLED module The purpose of this simulator is to improve the accuracy and efficiency of the OLED module design by supporting the user to designate or change the parameter values fixedly determined for each material in the simulator.

A simulation method of a simulation apparatus for an OLED module according to an embodiment of the present invention includes a receiving step of receiving parameters for each layer constituting an OLED module, and applying the parameters for each layer to preset drift diffusion equations and Poisson equations. The initial Fermi level and initial potential potential for each of the electrons and holes are calculated, and the initial Fermi level and the initial potential potential of the electrons and holes are substituted into the preset Maxwell-Boltzmann equation to obtain the initial values for the respective densities of electrons and holes. An initial value calculation step of calculating a value, and the initial value, the initial potential potential, and a preset voltage range in a preset function generated by applying the Poisson equation and the continuity equation to pdepe, a preset built-in function of the MATLAB program. A function application step of calculating respective densities and new potential potentials of new electrons and new holes by applying a selected voltage; and a determination step of calculating the pseudo Fermi level of each new hole and the mobility of each of the new electrons and new holes, and the selected voltage, the density of each of the new electrons and the new holes, the new potential potential, and the new electrons and the new holes It may include a current density calculation step of calculating the current density of each of the new electrons and the new holes based on the respective mobility.

As an example related to the present invention, the parameters for each layer constitute a first parameter for CuPc constituting a first layer among the plurality of layers, a second parameter for NPB constituting a second layer, and a third layer. It may be characterized in that it includes a third parameter for Alq3.

As an example related to the present invention, the step of calculating the initial value is through the following formula

Calculating the initial potential potential Φ, an initial value n for the density of electrons, and an initial value p for the density of holes,

Φ is the potential potential, n is the density of electrons, p is the density of holes, q is the charge amount of electrons, ε is the dielectric constant, k is the Boltzmann constant, T is the device temperature, and E _fn is the electron Fermi level of, E _fp is the Fermi level of the hole, E _LUMO is the energy level of the lowest unoccupied molecular orbital, E _HOMO is the energy level of the highest occupied molecular orbital, the N _LUMO may be characterized in that the lowest level non-concentration of occupied molecular orbital, N _HOMO is the concentration, the N _a of the top level occupied molecular orbital is the acceptor (acceptor) concentration, the N _D is the donor (donor) concentration have.

As an example related to the present invention, the function application step is through the following setting function,

Calculate n, which is the density of new electrons, p, which is the density of new holes, and Φ, which is the new potential potential,

Wherein ε is a dielectric constant and said q is the electron charge, the V _T is the voltage, the N _A is the acceptor (Acceptor) concentration, the N _D is the donor (Donor) concentration, the μ _n is a, the μ movement of the electron _p is hole mobility, R is a recombination rate constant, and G is a recombination rate.

As an example related to the present invention, the determining step is through the following formula,

Calculating the pseudo Fermi level E _fn of the new electron, the pseudo Fermi level E _{fp of} the new hole, the mobility μ _n of the new electron, and the mobility μ _{p of the new hole,}

Φ is the new potential potential, n is the density of new electrons, p is the density of new holes, q is the charge amount of electrons, ε is the dielectric constant, k is the Boltzmann constant, T is the device temperature, E _LUMO is the energy level of the lowest unoccupied molecular orbital, E _HOMO is the energy level of the highest occupied molecular orbital, N _LUMO is the concentration of the lowest unoccupied molecular orbital, N _HOMO may be characterized as the concentration of the highest occupied molecular orbital.

As an example related to the present invention, the current density calculation step is through the following formula,

Calculate the current density J _n of the new electrons and the current density J _{p of the new holes,}

Wherein q is the charge amount of electrons, μ _n is the mobility of new electrons, μ _p is the mobility of new holes, and Φ is the new potential potential.

As an example related to the present invention, the function application step selects a voltage while sequentially increasing the voltage within the preset voltage range, and corresponds to the existing voltage selected before the selected voltage when the selected voltage is changed according to the voltage increase By applying the calculated density and potential potential of each electron and hole to the set function together with the new voltage selected according to the voltage increase instead of the initial value and the initial potential potential, respectively, corresponding to the new voltage, each electron and hole calculates the density and potential potential of the new electrons and new holes calculated in correspondence to the selected voltage for each of the plurality of different selected voltages and corresponds to the previous voltage selected before the selected voltage A specific voltage that is a selected voltage when the difference calculated by comparing the calculated density and potential potential of each electron and hole with the corresponding properties is less than or equal to a preset reference value and the new electron when the difference value is less than or equal to the reference value And it may be characterized in that each of the new hole density and the new electrostatic potential are applied to the determination step as optimum values.

A simulation apparatus for an OLED module according to an embodiment of the present invention includes a receiver for receiving parameters for each layer constituting the OLED module, and by applying the parameters for each layer to preset drift diffusion equations and Poisson equations, respectively, for electrons and holes Calculating the initial Fermi level and initial potential potential for , and substituting the initial Fermi level and initial potential potential of the electrons and holes into a preset Maxwell-Boltzmann equation to calculate an initial value for each density of electrons and holes By applying the initial value, the initial constant potential potential, and a voltage selected within the preset voltage range to the setting function generated by applying the Poisson equation and the continuity equation to the calculator and pdepe, which is a preset built-in function of the MATLAB program, a new A function application unit for calculating the respective densities and new potential potentials of electrons and new holes; A determination unit for calculating the Fermi level and the mobility of each of the new electrons and new holes, and the selected voltage, the density of each of the new electrons and the new holes, the new electrostatic potential potential, and the mobility of the new electrons and the new holes and a current density calculator for calculating current densities of each of the new electrons and the new holes.

The present invention can not only provide a simulator in which a user can directly designate layers and parameter values for an OLED module as a design target, but also solve Poisson's equations and continuity equations at once using the MATLAB built-in function pdepe. While providing convenience, it is possible to reduce costs, simplify the simulation calculation process, and ensure easy user accessibility compared to existing simulators, and to improve the low efficiency caused by increasing the voltage. It has the effect of supporting the design of a multi-layer OLED module that can emit light with high accuracy.

1 and 2 are exemplary views of the basic structure and operation principle of an OLED.
3 is a flowchart of a simulation method of a simulation apparatus for an OLED module according to an embodiment of the present invention.
4 to 7 are graphs showing the Fermi level, the electron concentration, the hole concentration, the intrinsic semiconductor concentration, and the positive potential potential according to the applied voltage calculated according to an embodiment of the present invention.
8 to 23 are views showing numerical analysis results according to the operation of the simulation apparatus according to the embodiment of the present invention.
24 is a detailed configuration diagram of a simulation apparatus according to an embodiment of the present invention.

Hereinafter, a detailed operation configuration of a simulation device (hereinafter, a simulation device) for an OLED (Organic Light Emitting Diodes) module according to an embodiment of the present invention will be described with reference to the drawings.

Prior to the description, the basic structure and operation principle of an OLED module composed of multiple layers will be described with reference to FIG. 1 . Multilayer OLED is basically an ITO substrate and a hole transport layer (emissive layer), an electron It consists of an electron transport layer and a metal cathode.The layers of a multilayer OLED each have different highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) layers. The position of different LUMO/HOMO between adjacent organic interfaces can lower the voltage as free charge carriers pass through the transport layer, as well as the position of different LUMO/HOMO in the transport layer. It has a strong effect on the diffusion of excitons due to the recombination phenomenon caused by the barrier caused by the difference in energy level, and consequently has the advantages of low voltage and high efficiency.

FIG. 2 is an exemplary diagram of an operation principle of an OLED module composed of multiple layers, and as shown, the OLED module has an OLED structure composed of three layers.

This structure is a layer called HTL, EML, and ETL, respectively. HTL is a hole transfer layer, EML is an emitting layer, and ETL is an electron transfer layer. When voltage is applied, holes injected from the anode move to EML through HTL, and electrons injected from cathode also move to EML through ETL. When electrons and holes met in EML are located on the same molecule and are in a spatially close state, some of them recombine and the generated excitons fall to low energy, which is the luminance phenomenon. am.

In the configuration of the above-described OLED module, the substrate is a basic support for supporting the OLED, and most may be made of a material such as plastic, foil, or glass.

In addition, indium tin oxide (ITO) is a material generally used for the anode side. This material is transparent and has a high work function as a conductor, and it can be said that it is very suitable for use as an anode layer by increasing hole injection.

In addition, barium, calcium and aluminum, which have a smaller work function than the anode, are generally used as the cathode layer (cathode), which makes it easier to inject into the electons LUMO. In the present invention, the cathode layer is described by taking Lithium Fluoride (LiF) as an example.

In addition, the hole transport layer is a material typically used CuPc, the light emitting layer is a material mainly composed of organic plastic molecules, NPB (NPD) 1,4-bis (1-naphthylphenylamino) biphenyl can be used as the light emitting layer. have. In addition, Alq3 may be used as the electron transport layer.

The present invention provides a simulation apparatus that supports the design of the above-described OLED module, and the simulation apparatus of the present invention is cheaper than the existing simulation methods and guarantees user's ease of use and high accuracy, which will be described below. It will be described in detail.

3 is an operation flowchart of a simulation apparatus according to an embodiment of the present invention.

As shown, the simulation apparatus may receive parameters for each layer constituting the OLED module as a user input (S1).

In this case, the parameters for each layer are a first parameter for CuPc constituting a hole transport layer that is a first layer among the plurality of layers, a second parameter for NPB constituting a light emitting layer that is a second layer, and a third layer. A third parameter for Alq3 constituting the electron transport layer may be included.

In addition, the simulation apparatus calculates an initial Fermi level and an initial potential potential for each of electrons and holes by applying the parameters for each layer to a preset drift-diffusion equation and a Poisson equation. and (S2), and substituting the initial Fermi level and initial potential potential of the electron and hole into a preset Maxwell-Boltzmann equation to calculate an initial value for each density of the electron and hole. can be performed (S3).

In this case, the carrier movement of the OLED module may be calculated through the drift-diffusion equation and the Poisson equation according to Equation 1 below.

_where J n is the current density of electrons, J _p is the current density of holes, q is the charge amount of electrons, R is the recombination rate constant, n is the density of electrons, p is the density of holes, Φ is the potential potential, ε is It is the permittivity of organic matter. Here, the respective concentrations of electrons and holes of the OLED can be expressed as in Equation 2 below.

In this case, Φ is the potential potential, n is the density of electrons, p is the density of holes, q is the charge amount of electrons, ε is the dielectric constant, k is the Boltzmann constant, T is the device temperature, the E _fn is the Fermi level of the electron, E _fp is the Fermi level of the hole, E _LUMO is the energy level of the lowest unoccupied molecular orbital, E _HOMO is the energy of the highest occupied molecular orbital level, the N _LUMO is the lowest concentration level ratio, N _HOMO of occupied molecular orbital is the concentration, the N _a of the highest occupied molecular orbital level is an acceptor (acceptor) concentration N _D is the donor (donor) concentration.

Therefore, the simulation apparatus applies the layer-by-layer parameter to the drift-diffusion equation and Poisson equation according to Equation 1 and the Maxwell-Boltzmann equation according to Equation 2 in the initial value calculation step to apply the initial constant potential potential Φ, n, which is an initial value for the density of electrons, and p, which is an initial value for the density of holes, can be calculated.

Meanwhile, the structure of the OLED module can be seen from the graphs for LUMO, HOMO, and similar Fermi levels of electrons and holes of the OLED module when the applied voltage is 6V as shown in FIG. 4 . At this time, in ITO (Indium Tin Oxide) where the boundary condition is x=0, it is initially _{assumed that E fn} , E _fp change linearly.

Accordingly, E _fn and E _fp may be expressed as in Equation 3 below.

In this case, V _A may be an applied voltage, V _C may be a cathode voltage, L may be a light output, and x may be a spatial value.

In addition, as described above, graphs of Ec(LUMO), Ev(HOMO), E _fn (electron-like Fermi level), and E _fp (hole-like Fermi level) when the applied voltage is 0V may be shown as shown in FIG. 5 .

Also, as described above, _{graphs of the electron concentration n old} , the hole concentration p _old , and the intrinsic semiconductor concentration n _i when the applied voltage is 0V may be shown in FIG. 6 .

In addition, as described above, _{a graph of the positive potential potential Φ old} when the applied voltage is 0V may appear as shown in FIG. 7 .

In addition, the simulation device, the initial value and the initial constant potential potential and the preset voltage range to the set function generated by applying the Poisson equation and the continuity equation to pdepe, which is a built-in function of a preset matlab program. A function application step of calculating the density and new potential potential of each new electron and new hole by applying the selected voltage may be performed (S4).

In this case, the Poisson equation and the continuity equation can be expressed by Equation 4 below.

In this case, V _T is voltage, μ _n is electron mobility, μ _p is hole mobility, R is a recombination rate constant, and G is a recombination rate.

In addition, the built-in function pdepe of the MATLAB program is shown in Equation 5 below.

The pdepe holds when t ₀ ≤ _{t ≤ t 1} and a ≤ x ≤ b, t is time, and intervals a and b for x must be finite. m is 0, 1, or 2, which means slab symmetry, cylinder symmetry, and sphere symmetry, respectively.

는 플럭스항을 의미하며,

는 소스항을 의미한다.In addition, in Equation 5

is the flux term,

is the source term.

By applying the Poisson equation and the continuity equation according to Equation 4 to the pdepe according to Equation 5, a setting function as shown in Equation 6 below may be preset in the simulation apparatus.

The simulation device applies a voltage selected within a preset voltage range by applying the initial potential potential, an initial value for electron density, and an initial value for hole density to Equation 6, which is the setting function. It is possible to calculate n, which is the density of new electrons, p, which is the density of new holes, and Φ, which is the new potential potential.

In the above configuration, m is 0, and c in the pdepe built-in function means a diagonal element of a square matrix. Therefore, when it is converted into an expression for substituting into the simulation code, Equation 7 is shown below.

In addition, the conversion equation for the flux term is as Equation 8 below.

In addition, the conversion equation for the source term is as shown in Equation 9 below.

In the above equation, x is a space value, t is a time value, and u ₁ , u ₂ , and u ₃ are variables, respectively.

On the other hand, the simulation device, using the density of each of the new electrons and the new holes, the new potential potential, and the selected voltage, the pseudo Fermi level of each of the new electrons and the new holes and the mobility of each of the new electrons and the new holes A determination step of calculating ? may be performed (S9).

In this case, the simulation device calculates the pseudo-Fermi level E _fn of the new electrons, the pseudo Fermi level E _{fp of} the new holes, the mobility μ _n of the new electrons, and the mobility μ _{p of the new holes through Equation 10 below.} can be calculated.

In this case, in Equation 10, Φ is the new potential potential, n is the density of new electrons, p is the density of new holes, q is the charge amount of electrons, ε is the dielectric constant, and k is the Boltzmann constant , where T is the device temperature, E _LUMO is the energy level of the lowest unoccupied molecular orbital, E _HOMO is the energy level of the highest occupied molecular orbital, and N _LUMO is the lowest level The concentration of unoccupied molecular orbitals, N _HOMO, is the concentration of the highest occupied molecular orbital.

In addition, the simulation device, based on the selected voltage, the density of each of the new electrons and the new holes, the new electrostatic potential potential, and the respective mobility of the new electrons and the new holes, the current density of each of the new electrons and the new holes A current density calculation step of calculating ? may be performed (S10).

In this case, the simulation apparatus may _{calculate the current density J n} of the new electrons and the current density J _p of the new holes through Equation 11 below.

In this case, in Equation 11, q is the charge amount of electrons, μ _n is the mobility of new electrons, μ _p is the mobility of new holes, and Φ is the new potential potential.

Meanwhile, in the above configuration, the simulation device selects a voltage while sequentially (sequentially) increasing the voltage within the preset voltage range (S7, S8), and when the selected voltage is changed according to the voltage increase, the selected voltage The new voltage by applying the density and the potential potential of each electron and hole calculated in response to the previously selected existing voltage to the setting function together with the new voltage selected according to the voltage increase instead of the initial value and the initial potential potential, respectively The density and potential potential of each of electrons and holes are calculated in correspondence with the selected voltages, and the density and new potential potential of each of the new electrons and holes calculated in response to the selected voltage for each of the plurality of different selected voltages are applied to the selected voltage. When the respective densities and potential potentials of electrons and holes calculated in response to the previous voltage previously selected are compared with the corresponding properties (S5), and the difference value calculated according to this (by comparison) is less than or equal to a preset reference value (reference value) When the specific voltage, which is the selected voltage (when converges to below the reference value), and the difference value are below the reference value (when converges below the reference value), the density of each of the new electrons and the new hole and the new potential potential are set to the optimum values, respectively and can be applied to the determination step (S6).

That is, the density of each of the new electrons and the new holes used when the simulation device performs the determining step is a loop that performs the comparison while sequentially increasing the voltage within the voltage range in the function application step. Density (density-related optimal value) for each electron and hole calculated corresponding to the specific voltage (threshold voltage) obtained in the repeating process, and the selected voltage used in the determining step is the specific voltage (voltage-related optimal value) ), and the new potential potential used in the determination step is the constant potential potential (optimal value related to the constant potential potential) calculated in the step of applying the function corresponding to the specific voltage.

Through this, the simulation device calculates the optimal value at the threshold voltage so that the multi-layer OLED module at the lowest voltage that can emit light through the determination step and the current density calculation step can be designed with high accuracy. Support.

8 to 23 are views showing numerical analysis results according to the operation of the simulation apparatus as described above.

Fig. 8(a) is a graph showing the positive potential potential Φ when the applied voltage is 0V, and Fig. 8(b) is a graph showing the positive potential potential Φ when the applied voltage is 0V.

9 is a graph illustrating an electric field when an applied voltage is 0V, and FIG. 10 is a graph illustrating an electric field when an applied voltage is 5V.

11 is a graph showing the concentration of electrons and holes when the applied voltage is 0V, FIG. 12 is a graph showing the concentrations of electrons and holes when the applied voltage is 3V, and FIG. 13 is the electron and hole concentrations when the applied voltage is 5V. It is a graph showing the concentration.

14 is a graph showing an energy band diagram when an applied voltage is 0V, FIG. 15 is a graph showing an energy band diagram when an applied voltage is 3V, and FIG. 16 is a graph showing an energy band diagram when an applied voltage is 5V. .

17 is a graph showing a current density corresponding to an applied voltage of a multi-layer OLED module.

18 is a graph showing current densities corresponding to applied voltages at 40 nm, 50 nm, and 60 nm of an electron blocking layer (EBL).

19 is a graph showing current densities corresponding to applied voltages at electron blocking layer (EBL) 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm and 80 nm.

20 is a graph showing a recombination rate according to a device length when an electron blocking layer (EBL) is 40 nm, 50 nm, or 60 nm.

21 is a graph showing the current density in each EBL (electron blocking layer) when a constant voltage is applied.

22 is a graph showing luminance output corresponding to an applied voltage at 40 nm, 50 nm, and 60 nm of an electron blocking layer (EBL).

23 is a graph illustrating a luminance output corresponding to a current density when an electron blocking layer (EBL) is 40 nm.

As described above, the simulation device obtains an electrostatic potential (electrostatic potential) obtained by analyzing the Poisson equation by a numerical method, and then uses it to interpret the continuity equation by a numerical analytical method. Calculate electron density and hole density.

In addition, the simulation apparatus is configured to again calculate electron quasi-Fermi-level ( _{E fn ) and hole quasi-Fermi-level (E fp} ) values, which are quasi-Fermi-levels of electrons and holes from the calculated values. , and then substituting them into the equations to obtain electron density and hole density again to obtain new electron density, hole density, and potential potential. With these values, if the difference with the values of electron density, hole density, and electrostatic potential just before iteration of the loop ^{converges to 10 -5} or less, numerically, these values are the final result. do.

At the same time, the threshold voltage can be obtained by continuously increasing the voltage.

As described above, the present invention can provide a simulator in which a user can directly designate a layer and parameter values for an OLED module as a design target, and Poisson Equation and Continuity Equation using the MATLAB built-in function pdepe function. While providing the convenience of solving the problem of It can support the design of a multi-layer OLED module that can emit light with high accuracy.

24 is a block diagram of a simulation apparatus according to an embodiment of the present invention.

As shown, the simulation apparatus 100 according to an embodiment of the present invention includes a receiver 110 that receives parameters for each layer constituting an OLED module, and a preset drift diffusion equation and a Poisson equation for the parameters for each layer. to calculate the initial Fermi level and initial potential potential for each electron and hole by applying to The calculation unit 120 for calculating the initial value of , and the initial value and the initial potential potential and the preset The function application unit 130 for calculating the respective densities and new potential potentials of new electrons and new holes by applying a voltage selected within the voltage range, and the respective densities of the new electrons and new holes, the new potential potential and the selected The determination unit 140 for calculating the pseudo Fermi level of each of the new electrons and the new holes and the mobility of each of the new electrons and the new holes by using the voltage, and the selected voltage and the density and newness of each of the new electrons and the new holes It may be configured to include a current density calculator 150 for calculating the current density of each of the new electrons and the new holes based on the potential potential and the respective mobility of the new electrons and the new holes.

At this time, the receiving unit 110 , the calculating unit 120 , the function applying unit 130 , the determining unit 140 , and the current density calculating unit 150 are configured in the simulation apparatus 100 , and the simulation apparatus 100 . It may be composed of a component included in a control unit configured in the simulation apparatus 100 that performs an overall control function of .

In addition, the control unit can execute various functions described in the present invention by using the programs and data stored in the storage unit configured in the simulation device 100, and the control unit includes RAM, ROM, CPU, GPU, and a bus. RAM, ROM, CPU, GPU, etc. can be connected to each other through a bus.

In addition, the simulation apparatus 100 may further include various components such as a communication unit for interface and communication with an external device, and a user input unit for receiving a user input.

Those of ordinary skill in the art to which the present invention pertains may modify and modify the above-described contents without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: simulation device 110: receiver
120: calculation unit 130: function application unit
140: determination unit 150: current density calculation unit

Claims (8)

In the simulation method of a simulation device for an OLED module,
A receiving step of receiving parameters for each layer constituting the OLED module;
By applying the parameters for each layer to preset drift diffusion equations and Poisson equations, the initial Fermi level and initial potential potential for each electron and hole are calculated, and the initial Fermi level and initial potential potential of the electron and hole are calculated in advance. an initial value calculation step of calculating an initial value for each density of electrons and holes by substituting the set Maxwell-Boltzmann equation;
New electrons and new holes by applying the initial value, the initial constant potential potential, and a voltage selected within the preset voltage range to the set function generated by applying the Poisson's equation and the continuity equation to pdepe, which is the built-in function of the preset MATLAB program a function application step of calculating each density and a new potential potential;
a determining step of calculating a pseudo Fermi level of each of the new electrons and new holes and a mobility of each of the new electrons and new holes using the density of each of the new electrons and the new holes, the new potential potential, and the selected voltage; and
Current density calculation step of calculating the current density of each of the new electrons and the new holes based on the selected voltage, the density of each of the new electrons and the new holes, the new potential potential, and the mobility of each of the new electrons and the new holes ;
A simulation method for an OLED module comprising a.
The method according to claim 1,
The parameters for each layer include a first parameter for CuPc constituting the first layer among the plurality of layers, a second parameter for NPB constituting the second layer, and a third parameter for Alq3 constituting the third layer. A simulation method for an OLED module comprising:
The method according to claim 1,
The initial value calculation step is
through the formula

Calculating the initial potential potential Φ, an initial value n for the density of electrons, and an initial value p for the density of holes,
Φ is the potential potential, n is the density of electrons, p is the density of holes, q is the charge amount of electrons, ε is the dielectric constant, k is the Boltzmann constant, T is the device temperature, and E _fn is the electron Fermi level of, E _fp is the Fermi level of the hole, E _LUMO is the energy level of the lowest unoccupied molecular orbital, E _HOMO is the energy level of the highest occupied molecular orbital, the N _LUMO is the concentration of the lowest level unoccupied molecular orbital, N _HOMO is the concentration, the N _a of the top level occupied molecular orbital is the acceptor (acceptor) concentration, the N _D is OLED, characterized in that the donor (donor) concentration Simulation method for module.
The method according to claim 1,
The function application step is
Through the following setting function,

Calculate n, which is the density of new electrons, p, which is the density of new holes, and Φ, which is the new potential potential,
Wherein ε is a dielectric constant and said q is the electron charge, the V _T is the voltage, the N _A is the acceptor (Acceptor) concentration, the N _D is the donor (Donor) concentration, the μ _n is a, the μ movement of the electron _p is hole mobility, R is a recombination rate constant, and G is a recombination rate.
The method according to claim 1,
The determining step is
Through the following formula,

Calculating the pseudo Fermi level E _fn of the new electron, the pseudo Fermi level E _{fp of} the new hole, the mobility μ _n of the new electron, and the mobility μ _{p of the new hole,}
Φ is the new potential potential, n is the density of new electrons, p is the density of new holes, q is the charge amount of electrons, ε is the dielectric constant, k is the Boltzmann constant, T is the device temperature, E _LUMO is the energy level of the lowest unoccupied molecular orbital, E _HOMO is the energy level of the highest occupied molecular orbital, N _LUMO is the concentration of the lowest unoccupied molecular orbital, N _HOMO is a simulation method for an OLED module, characterized in that it is the concentration of the highest occupied molecular orbital.
The method according to claim 1,
The current density calculation step,
Through the following formula,

Calculate the current density J _n of the new electrons and the current density J _{p of the new holes,}
Wherein q is the charge amount of electrons, μ _n is the mobility of new electrons, μ _p is the mobility of new holes, and Φ is the new electrostatic potential potential.
The method according to claim 1,
The function application step is
The voltage is selected while sequentially increasing the voltage within the preset voltage range, and when the selected voltage is changed according to the increase in voltage, the density and potential potential of each of electrons and holes calculated in response to the existing voltage selected before the selected voltage are obtained. Instead of the initial value and the initial potential potential, respectively, the density and the potential potential of each of electrons and holes are calculated in response to the new voltage by applying to the set function together with the new voltage selected according to the increase in voltage, and a plurality of different The density and potential potential of each of the electrons and holes calculated in response to the previous voltage selected before the selection voltage and the density and potential potential of each of the new electrons and new holes calculated in response to the selected voltage for each selected voltage A specific voltage that is a selected voltage when the difference calculated by comparing the corresponding properties is less than or equal to a preset reference value, and the density of each of the new electrons and new holes and the new potential potential when the difference is less than or equal to the reference value, respectively A simulation method for an OLED module, characterized in that the optimum value is applied to the determination step.
a receiver for receiving parameters for each layer constituting the OLED module;
By applying the parameters for each layer to preset drift diffusion equations and Poisson equations, the initial Fermi level and initial potential potential for each electron and hole are calculated, and the initial Fermi level and initial potential potential of the electron and hole are calculated in advance. a calculator for calculating initial values for respective densities of electrons and holes by substituting the set Maxwell-Boltzmann equation;
New electrons and new holes by applying the initial value, the initial constant potential potential, and a voltage selected within the preset voltage range to the set function generated by applying the Poisson's equation and the continuity equation to pdepe, which is the built-in function of the preset MATLAB program a function application unit that calculates each density and a new potential potential;
a determination unit for calculating the pseudo Fermi level of each of the new electrons and the new holes and the mobility of each of the new electrons and the new holes by using the respective densities of the new electrons and the new holes, the new potential potential, and the selected voltage; and
A current density calculator for calculating the current density of each of the new electrons and the new holes based on the selected voltage, the density of each of the new electrons and the new holes, the new potential potential, and the mobility of each of the new electrons and the new holes ;
A simulation device for an OLED module comprising a.

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