JP2023005419A - Method and program for analyzing emission intensity attenuation measurement data, and emission intensity measurement device - Google Patents

Abstract

To provide an emission intensity attenuation measurement data analysis method which allows for accurately deriving quantum yields, emission ratios, etc. of multiple emission components such as an immediate fluorescence component and delayed fluorescence component of a delayed fluorescence material through simple steps.SOLUTION: A method of analyzing emission intensity attenuation measurement data involving multiple emission components is provided, the method comprising a fitting step using an exponentially modified Gaussian function.SELECTED DRAWING: None

Description

The present invention provides a method for analyzing measurement data of luminescence intensity decay containing a plurality of luminescence components, such as an immediate fluorescence component and a delayed fluorescence component of a delayed fluorescence material, a measurement data analysis program for luminescence intensity decay, and a luminescence intensity measurement device. Regarding.

A delayed fluorescence material is known as a luminescent material exhibiting high luminous efficiency. A delayed fluorescence material is a luminescent material that causes reverse intersystem crossing from an excited triplet state to an excited singlet state. It is said that high luminous efficiency can be obtained because both of the light emitted with the deactivation of the excited singlet state generated by the intercrossing is emitted. Among these lights, the light emitted through reverse intersystem crossing is called "delayed fluorescence" because it is observed later than the light due to direct excitation. The light is called "immediate fluorescence".
Here, when calculating the quantum yield, the luminescence ratio, etc. of the immediate fluorescence and the delayed fluorescence of the delayed fluorescence material, the emission intensity decay curve of the delayed fluorescence material is usually analyzed. Specifically, the time change of the emission intensity of the delayed fluorescence material is measured to obtain an emission intensity decay curve, and the emission quantum yield Φ _PF of the immediate fluorescence component and the delayed fluorescence component are calculated based on the fitting function applied to the decay curve. Calculate the quantum yield Φ _DF of Several proposals have been made for specific techniques for obtaining these quantum yields Φ _PF and Φ _DF (see Non-Patent Documents 1 and 2).

J. Am. Chem. Soc., 2014, 136, 18070. ChemRxiv, 14178113, 2021.

As described above, when calculating the quantum yields Φ _DF , Φ _PF , etc., first, the emission intensity decay curve of the delayed fluorescence material is analyzed. Here, the luminescence intensity decay curve has an initial luminescence intensity rising portion (immediate fluorescence increase region) and a luminescence intensity decaying portion. It was an object of analysis, and the rising portion of the luminescence intensity was not taken into consideration.
However, when the present inventors measured the luminescence intensity decay curve using various measuring devices, the pattern of the rising portion of the luminescence intensity differed depending on the measuring device. It was found that it affects the calculation results such as Here, the influence of the rising pattern can be avoided by measuring the device-dependent function (IRF) of the rising portion and using the exponential decay obtained by deconvolving the IRF and the emission intensity decay for analysis. Seem. However, it is not easy to correctly measure the IRF for the measurement sample, and the deconvolution calculation of the measured IRF and the emission intensity attenuation is extremely complicated and lacks practicality.

Therefore, in order to solve such problems of the prior art, the present inventors have developed an emission intensity attenuation method that can more accurately calculate the quantum yield, emission ratio, etc. of the immediate fluorescence component and the delayed fluorescence component in a simple process. The purpose of this study was to provide a method for analyzing measurement data.

As a result of intensive studies to solve the above problems, the present inventors have found that by fitting the measured luminescence intensity attenuation using an "exponentially modified Gaussian function", the IRF is affected. It has been found that the quantum yield, emission ratio, etc. of the immediate fluorescence component and the delayed fluorescence component can be calculated more accurately by a simple process, without the need for quantification. In addition, the inventors have also found that this can reduce the problem of different quantum yields and luminescence ratios calculated depending on the measurement device. The present invention has been proposed based on these findings, and specifically has the following configurations.

［３］ 各発光成分の発光割合を導出する、［１］または［２］に記載の方法。
［４］ 発光に関する速度定数を導出する、［１］～［３］のいずれか１項に記載の方法。
［５］ 前記複数の発光成分として、遅延蛍光材料からの即時蛍光成分と遅延蛍光成分を含む、［１］～［４］のいずれか１項に記載の方法。
［６］ 発光強度減衰の測定データを下記式（１１）でフィッティングする、［５］に記載の方法。

［７］ 前記即時蛍光成分の発光全体に対する発光割合（Ｓ_ＰＦ）を下記式（２０）で算出し、前記遅延蛍光成分の発光全体に対する発光割合（Ｓ_ＤＦ）を下記式（２１）で算出する、［６］に記載の方法。

［式（２０）および（２１）において、Ａ_１およびｋ_ｐは即時蛍光成分の傾きとピーク高さを制御している定数であり、Ａ_２およびｋ_ｄは遅延蛍光成分の傾きとピーク高さを制御している定数である。］
［８］ 前記複数の発光成分が３種以上の発光成分である、［１］～［５］のいずれか１項に記載の方法。
［９］ ［１］～［８］のいずれか１項に記載の方法を実行する、発光強度減衰の測定データ解析プログラム。
［１０］ 複数の発光成分を含む発光強度減衰を測定することができる測定部と、測定部にて得られた測定データを［１］～［８］のいずれか１項に記載の方法により解析する解析部を有する発光強度測定装置。 [1] A method of analyzing measured data of luminescence intensity decay containing a plurality of luminescence components, comprising the step of fitting with an exponentially modified Gaussian function.
[2] The method according to [1], wherein the exponentially modified Gaussian function is represented by the following formula (1).

[3] The method according to [1] or [2], wherein the emission ratio of each emission component is derived.
[4] The method according to any one of [1] to [3], wherein a rate constant for luminescence is derived.
[5] The method according to any one of [1] to [4], wherein the plurality of luminescent components include an immediate fluorescence component and a delayed fluorescence component from a delayed fluorescence material.
[6] The method according to [5], wherein the measured data of luminescence intensity attenuation is fitted by the following formula (11).

[7] Calculate the luminescence ratio (S _PF ) of the immediate fluorescence component to the total luminescence by the following formula (20), and calculate the luminescence ratio (S _DF ) of the delayed fluorescence component to the total luminescence by the following formula (21). , [6].

[In equations (20) and (21), A ₁ and k _p are constants controlling the slope and peak height of the immediate fluorescence component, and A ₂ and k _d are the slope and peak height of the delayed fluorescence component. is a constant that controls ]
[8] The method according to any one of [1] to [5], wherein the plurality of light-emitting components are three or more kinds of light-emitting components.
[9] A program for analyzing measurement data of luminescence intensity attenuation, which executes the method according to any one of [1] to [8].
[10] A measurement unit capable of measuring luminescence intensity attenuation containing a plurality of luminescence components, and analyzing the measurement data obtained by the measurement unit by the method according to any one of [1] to [8]. A luminescence intensity measurement device having an analysis unit that

According to the analysis method of the present invention, it is possible to more accurately calculate the quantum yields, luminescence ratios, and the like of a plurality of luminescence components in a simple process based on measurement data of luminescence intensity attenuation. Moreover, according to the analysis method of the present invention, it is possible to reduce the problem of different quantum yields and luminescence ratios calculated by measuring devices.

4 is a graph for explaining a Gaussian function as a device dependent function; 4 is a graph showing a luminescence intensity decay model including an immediate fluorescence component PF and a delayed fluorescence component DF. FIG. 3 is a graph showing an enlarged time scale of FIG. 2; FIG. FIG. 4 is a graph showing luminescence intensity decay data fitted with an exponential modified Gaussian function; FIG. 4 is a graph showing an analysis example of luminescence intensity decay data containing two types of luminescence components; 4 is a graph showing an analysis example of luminescence intensity decay data containing three types of luminescence components; 7 is a graph showing another analysis example of luminescence intensity decay data containing three types of luminescence components; 1 is a graph showing a conventional analysis example of luminescence intensity decay data containing two types of luminescence components;

The present invention will be described in detail below. Although the constituent elements described below may be described based on representative embodiments and specific examples, the present invention is not limited to such embodiments. In this specification, the numerical range represented by "-" means a range including the numerical values described before and after "-" as lower and upper limits.

<Method for analyzing measurement data of luminescence intensity attenuation>
A method (analysis method) of the present invention is a method of analyzing measurement data of luminescence intensity attenuation containing a plurality of luminescence components, characterized by including a step of fitting using an exponentially modified Gaussian function. and
In the present invention, “luminescence intensity attenuation including multiple luminescence components” means luminescence intensity attenuation including a plurality of luminescence components with different attenuation patterns, in other words, luminescence intensity attenuation that can be decomposed into a plurality of luminescence components with different attenuation patterns. means Such luminescence intensity attenuation can be expressed as the sum of multiple luminescence components. Examples of different attenuation patterns of luminescence intensity include the case where the attenuation constant k when the attenuation pattern is applied to the exponential decay is different between the luminous components, and the case where the functional expressions that apply the attenuation patterns are different between the luminous components. can be done. The plurality of luminescence components included in the luminescence intensity attenuation may be of two types, or may be of three or more types. The two types of luminescence components include an immediate fluorescence component and a delayed fluorescence component emitted by the delayed fluorescence material. Here, the “delayed fluorescence material” is a light-emitting material that causes reverse intersystem crossing from an excited triplet state to an excited singlet state. In addition, the "immediate fluorescence component" is the fluorescence emitted upon deactivation of the excited singlet state generated by direct excitation, and the "delayed fluorescence component" is generated by reverse intersystem crossing from the excited triplet state. It is the fluorescence emitted with the deactivation of the excited singlet state.
In the present invention, in the "measurement data of luminescence intensity attenuation" containing a plurality of luminescence components, the intensity of light detected from the sample to be measured after being irradiated with pulsed excitation light is plotted with time on the horizontal axis and luminescence intensity on the vertical axis. time-resolved spectra can be used. In the following description, "measured data of luminescence intensity attenuation" may be simply referred to as "luminescence intensity attenuation data". The time-resolved spectrum measurement device is not particularly limited. Specific examples include a streak camera and a luminescence lifetime measuring device (for example, Hamamatsu Photonics: Quantauras Tau).
The “exponentially modified Gaussian function” used in the present invention is a function obtained by using the convolution integral of the exponential function represented by the following formula (3) and the Gaussian function represented by the following formula (4). be. In the following description, the "exponentially modified Gaussian function" in the present invention may be referred to as "exponentially modified Gaussian function". As the "exponentially modified Gaussian function", for example, a function represented by the following formula (1) can be used.

Here, the exponential function represented by Equation (3) is a function representing the exponential decay of the luminescence intensity, and the Gaussian function represented by Equation (4) approximates the device dependent function (IRF) as is a function that represents In this way, the "exponentially modified Gaussian function" used in the present invention is, so to speak, a device-dependent function approximation formula superimposed on the exponential decay. Therefore, by fitting the measurement data of the luminescence intensity decay using this function, the difference in the rise pattern (immediate fluorescence intensity increase area) for each measuring device is corrected, and accurate fitting parameters can be derived. Also, the Gaussian function is expressed by Equation (4), which is a relatively simple equation, and by using this as the device-dependent function, a separate step of measuring the device-dependent function can be eliminated. Therefore, according to the analysis method of the present invention, the quantum yields, luminescence ratios, and the like of a plurality of luminescence components can be calculated more accurately through simple steps. In addition, it is possible to reduce the problem of different quantum yields and luminescence ratios calculated by measuring devices.

As an example of deriving the "exponentially modified Gaussian function", the method of deriving Equation (1) will be described below.
As described above, Equation (1) is a function obtained by convolving the exponential function represented by Equation (3) and the Gaussian function represented by Equation (4). The convolution of these equations is represented by Equation (5) below.

The following formula (6) is derived by sequentially transforming the formula (5) as shown in the following formulas.

Next, variable conversion shown in the following formula (7) is performed.

By modifying the above equation (6) as shown in the following equation (8) and substituting Z shown in the equation (7), the following equation (9) is derived.

Also, the Gaussian complementary error function erfc(x) is defined by the following equation (10).

Substituting erfc(x) defined in equation (10) into equation (9) yields the function expressed in equation (1) as the “exponentially modified Gaussian function”.

For the definition of each symbol in Formula (1), the above description can be referred to.
In the analysis method of the present invention, it is preferable to analyze the measurement data of luminescence intensity attenuation by fitting using equation (1). Here, the fitting using the formula (1) can be performed by fitting the measurement data of the luminescence intensity attenuation with a fitting function including the function represented by the formula (1), for example. Fitting functions including the function represented by Equation (1) include, for example, the function represented by Equation (11) and fitting functions in modified examples. By using the fitting parameters A and k determined by such fitting, it is possible to derive the quantum yields and luminescence ratios of a plurality of luminescence components. In addition, since k corresponds to the decay constant of exponential decay, by deriving k, it is possible to evaluate the characteristics of the sample to be measured, such as the rate constant related to luminescence and the luminescence lifetime. FIG. 1 shows a graph of the Gaussian function (IRF) when σ in Equation (4) is 3.0×10 ⁻⁹ and μ is −3.0×10 ⁻⁹ . As a reference example, FIG. ^{1 shows} formula ( ¹ ) and A functional graph of equation (3) is also shown.

[Embodiment of analysis method]
Next, a specific procedure of the analysis method of the present invention will be described by taking as an example a case of analyzing luminescence intensity attenuation data containing two types of luminescence components and calculating the luminescence ratio and luminescence quantum yield of each luminescence component. do.

[1] Determination process of parameters σ and μ In this process, the luminous intensity decay data (IRF) of the excitation light is measured using a scattering medium as a standard sample, and the rising portion of the luminous intensity is fitted using equation (4). , parameters σ and μ. At this time, a plurality of Gaussian functions can be used to determine reference values of a plurality of parameters σ _n and μ _n . n is an identification value assigned to each Gaussian function used for fitting. By performing this step, it is possible to use an index for determining how many Gaussian functions to be used when performing fitting using a plurality of exponentially modified Gaussian functions. Note that this step is performed as necessary, and may or may not be performed.
In the analysis method of this embodiment, the values of σ and μ determined in this step can be used as the initial values of the fitting parameters of Equation (1) for analyzing the luminescence intensity attenuation data of the sample to be measured.

[2] Fitting step of luminescence intensity decay data In this step, the time-resolved luminescence spectrum (luminescence intensity decay data) measured for the sample to be measured is fitted using an exponentially modified Gaussian function such as Equation (1). to determine the fitting parameters. Here, the values of σ and μ determined in step [1] can be used as the initial values of the fitting parameters in equation (1).
The fitting using the exponentially modified Gaussian function can be performed by fitting the luminescence intensity attenuation data with a fitting function that is the sum of a plurality of luminescence components described by the exponentially modified Gaussian function. This fitting will be described below with reference to the emission intensity attenuation model shown in FIGS.
2 and 3 show an example of an emission intensity decay model of a delayed fluorescence material to be analyzed. Here, FIG. 3 is an enlarged view of the time scale of FIG. In the luminescence intensity decay model shown in FIGS. 2 and 3, the plot of "luminescence intensity decay (SUM)" corresponds to the luminescence intensity decay data to be analyzed. As shown in each figure, this luminescence intensity attenuation is decomposed into a luminescence component with a high decay rate (immediate fluorescence component PF) and a luminescence component with a low decay rate (delayed fluorescence component DF). For luminescence intensity attenuation data containing such two types of luminescence components, fitting can be performed using the following equation (11) as a fitting function.

When the luminescence intensity decay data containing two luminescence components is fitted by Equation (11), the values of A ₁ , k _p , A ₂ , and k _d as fitting parameters are determined. For example, in the emission intensity attenuation model shown in FIGS. 2 and 3, A ₁ , k _p , A ₂ , and k _d are determined to the following values by fitting plots of emission intensity attenuation using equation (11).
μ: -3 × 10 ^-9
σ: 3×10 ⁻⁹
A1: ₁₀₀₀₀
k _p : 9×10 ⁷
_A2 : 200
_kd : 4×10 ⁶

[3] Step of calculating the emission ratio and quantum yield of a plurality of luminescent components In this step, using the values of the fitting parameters A ₁ , k _p , A ₂ , k _d determined in the above step [2], By calculating the emission ratio of the fluorescence component PF and the delayed fluorescence component DF and calculating the product of the emission ratio and the emission quantum yield Φ _PLQY of the sample to be measured, the quantum yield Φ _PF of the immediate fluorescence component PF and the delayed fluorescence Calculate the quantum yield Φ _DF of the component DF.
A calculation formula for calculating the emission ratio using A ₁ , k _p , A ₂ and k _d and a calculation formula for calculating the quantum yields Φ _PF and Φ _DF will be described below.

In the delayed fluorescence material, a delayed fluorescence component DF is generated as the immediate fluorescence component PF decays. When such luminescence intensity decay is represented by an exponentially modified Gaussian function, the immediate fluorescence component PF is described as shown in Equation (12) below, and the delayed fluorescence component DF is described as shown in Equation (13) below.

Therefore, the luminescence intensity attenuation as the sum (SUM) of the immediate fluorescence component PF and the delayed fluorescence component DF is expressed by the following formula (14), which is the sum of the formulas (12) and (13).

On the premise of the quantum yield by the cumulative distribution function , first, for reference, the calculation of the quantum yields Φ _PF and Φ _DF using the cumulative distribution function of the Gaussian function will be described.
A general exponential modified Gaussian function is represented by the following formula (S1).

A cumulative distribution function CDF for this exponentially modified Gaussian function is represented by the following equation (S2).

Apply the CDF (x, λ) represented by formula (S2) to the immediate fluorescence component PF (corresponding term in formula (12)) and the delayed fluorescence component DF (corresponding term in formula (13)) in formula (14) , the following equation (S3) representing the cumulative distribution function φ _PF of the immediate fluorescence component PF and the following equation (S4) representing the cumulative distribution function φ _DF of the delayed fluorescence component DF are obtained.

Here, the ratio of the cumulative distribution functions φ _PF and φ _DF to the sum of the cumulative distribution functions (φ _PF +φ _DF ) corresponds to the light emission ratio of each light emission component PF and DF. Therefore, by calculating the product of their emission ratio and the emission quantum yield Φ _PLQY of the measurement target, the quantum yield Φ PF of the immediate fluorescence component _PF and the quantum yield Φ _DF of the delayed fluorescence component DF are calculated. be. Below, as a reference example of calculation, the quantum yields Φ _PF and Φ _DF are calculated by calculation using the cumulative distribution functions Φ _PF and Φ _DF for the emission intensity decay data (measured values) of the delayed fluorescence material shown in FIG. The results are shown.

Calculation of quantum yields Φ _PF , Φ _DF using fitting parameters A ₁ , k _p , A ₂ , k _d Next, quantum yields Φ _PF , Φ using fitting parameters A ₁ , k _p , A ₂ , k _d Calculation of _DF will be described.
First, in order to simplify the explanation, the above equation (14) is rewritten as the following equation (15) for simplification.

In Equation (15), the first term corresponds to Equation (12) representing the immediate fluorescence component PF, and the second term corresponds to Equation (13) representing the delayed fluorescence component DF. The ratios to the total area correspond to the emission ratios S _PF and S _DF of the respective emission components PF and DF. If the area integral of the first term is expressed as a ratio to the total area, the formula (16) is obtained, and if the area integral of the second term is expressed as a ratio to the total area, the formula (18) is obtained. By transforming each formula, the following formulas (17) and (19) are derived.

Since M and N in equations (17) and (19) are derived from Gaussian functions, the following equations (20) and (21) are obtained by removing them from the equations and using only exponential decay components. Here, SPF represented by Equation (20) corresponds to the emission ratio of the immediate fluorescence component _PF , and SDF represented by Equation (21) corresponds to the emission ratio of the delayed fluorescence component _DF . Therefore, by substituting the values of A ₁ , k _p , A ₂ , and k _d determined in step [2] into each formula and calculating, the emission ratios S _PF and S _DF of each of the emission components PF and DF are calculated. be done.

Further, as shown in the following formulas (22) and (23), the quantum yield Φ _PF is expressed as the product of the formula (20) representing the emission rate S _PF and the emission quantum yield Φ _PLQY , and the quantum yield Φ _DF is expressed as the product of Eq. (21) representing the emission fraction S _PF and the quantum yield Φ _PLQY . Therefore, the quantum yield Φ _PF is calculated by calculating the product of the value of the emission ratio S _PF obtained by the calculation of formula (20) and the measured value of the emission quantum yield Φ _PLQY of the measurement object, and the formula ( Quantum yield Φ _DF is calculated by multiplying the value of luminescence ratio S _DF obtained in the calculation of 21) and the measured value of luminescence quantum yield Φ _PLQY of the object to be measured.

For example, if the equations (22) and (23) are calculated with Φ _PLQY =1 for the emission intensity attenuation model shown in FIGS. 2 and 3, the quantum yields Φ _PF and Φ _DF are calculated as follows.
Quantum yield Φ _PF : 0.645
Quantum yield Φ _DF : 0.355

Further, the results of calculating the quantum yields Φ _PF and Φ _DF by calculating the equations (22) and (23) for the measurement data (actually measured values) of the emission intensity attenuation of the delayed luminescent material shown in FIG. 4 are shown below. .

Thus, the quantum yields Φ _PF and Φ _DF calculated by the equations (22) and (23) completely match the quantum yields Φ _PF and Φ _DF obtained from the cumulative distribution function of the Gaussian function. . From this, it was confirmed that the emission ratio and the quantum yield can be calculated by using the values of the fitting parameters A ₁ , k _p , A ₂ , and k _d of the exponentially modified Gaussian function.
Also, from this, the exponential function Iexpfit(t) after deconvoluting the Gaussian function from Equation (15) is represented by the following Equation (24), and the common term of Equation (24) is calculated. It was confirmed to be represented by the following formula (25) obtained.

[Modification]
In the above embodiment, the device-dependent function is represented by one type of Gaussian function, and the exponential modified Gaussian function obtained by convolving the Gaussian function and the exponential function is used as the fitting function for analysis. The fitting function used in the analysis method of the present invention may include two or more exponential modified Gaussian functions. Here, "two or more exponentially modified Gaussian functions" means that when the device dependent function (IRF) is represented by two or more Gaussian functions, each of the two or more Gaussian functions is an exponential function. It means two or more exponential modified Gaussian functions transformed by convolution.
A method of analyzing emission intensity decay using two or more exponentially modified Gaussian functions is described below. In the following description, the Gaussian function representing the device-dependent function may be referred to as "Gaussian function (IRF)".

(Analysis of two-component damping system)
An example of a fitting function for analyzing luminescence decay measurement data containing two luminescence components, including an exponentially modified Gaussian function transformed from three Gaussian functions representing the IRF, is shown below.

式において、Ｒはガウス関数の相対強度であり、μはガウス曲線のピーク位置であり、σはガウス曲線の幅である。Ａおよびｋは指数関数的減衰の傾きとピーク高さを制御している定数である。各記号の下付き添え字（例えば１、２、３、ｎ、ｍ）は、ガウス関数毎または指数関数毎に割り振られた識別値である。これらの記号の定義は、以下の各式においても同じである。

where R is the relative strength of the Gaussian function, μ is the peak position of the Gaussian curve, and σ is the width of the Gaussian curve. A and k are constants controlling the slope and peak height of the exponential decay. The subscripts of each symbol (eg, 1, 2, 3, n, m) are identifying values assigned to each Gaussian or exponential function. The definitions of these symbols are the same in each of the following formulas.

The exponential function Iexpfit(t) of the attenuation curve obtained by deconvolving the Gaussian function from this fitting function is shown below.

_{In this example} , the _quanta Yields Φ _PF , Φ _DF can be calculated.

For the measurement data (actually measured values) of the _{luminescence intensity attenuation} shown in _FIG . The results of calculating the quantum yields Φ _PF and Φ _DF by substituting the values into the equations (22) and (23) are shown below.

Quantum yield Φ _PF : 0.726512793
Quantum yield Φ _DF : 0.073487207

From this calculation result, when using the exponentially modified Gaussian function converted from three types of Gaussian functions (IRF) for fitting, more accurate calculation results can be obtained. It can be seen that there is no significant difference in the calculation results compared to the case of using an exponentially modified Gaussian function with one type of Gaussian function as the device-dependent function. On the other hand, it has been found that the method works effectively and can provide a more correct fit when exhibiting complex device dependent functions, such as those represented by more Gaussian functions as shown in FIG.

(Analysis of multi-component damping system)
Further, the measurement data of luminescence intensity attenuation analyzed by the analysis method of the present invention is not limited to data containing two types of luminescence components, and may contain three or more types of luminescence components (multi-component decay system). . An example of a fitting function for analyzing luminescence decay measurement data containing three or more luminescence components, including an exponentially modified Gaussian function transformed from three Gaussian functions representing the IRF, is shown below.

A general formula for this fitting function is expressed as follows.

Here, since _Rn represents the relative strength of each Gaussian function, setting at least one to 1 facilitates calculation. In particular, when R ₁ =1 and n=1 is selected, the calculation becomes less complicated.
The general expression of the exponential function of the attenuation curve obtained by deconvolving the Gaussian function from this fitting function is shown below.

Calculation of Emission Rate and Quantum Yield of Multi-Component Attenuation System Next, the calculation of the emission rate and quantum yield of a multi-component attenuation system will be described.
An example of the exponential expression of the decay curve obtained by deconvolving the Gaussian function from the fitting function of the exponentially modified Gaussian function of the multi-component system is shown below. This exponential formula shows the case where each luminescence component attenuates independently without being affected by the attenuation of other luminescence components.

Here, the emission ratio of each emission component is represented by the following formula (26).

The fitting parameter values corresponding to A _m , _km , A _z , and k _z in Equation (26) are substituted to calculate the emission ratio of each emission component, and the emission ratio and the emission quantum yield Φ of the sample to be measured are calculated. By calculating the product of PLQY, the quantum yield _Φm of each emission component can be calculated.

Further, another example of the exponential expression of the attenuation curve obtained by deconvolving the Gaussian function from the fitting function of the exponentially modified Gaussian function of the multicomponent system is shown below. This exponential formula has decay constants such that decay of the first emission component produces a second emission component, decay of the second emission component produces a third emission component, and so on. It represents the case where a luminescence component with a small attenuation constant is generated due to the attenuation of a large luminescence component.

_Sm is represented by the following formula, where _Sm is the light emission ratio of each light emission component.

When the ratio of light emission of each light emitting component is represented by a general formula, the following formula (27) is obtained.

By substituting the fitting parameter values corresponding to A _z , km , km ₋₁ , and _{k z} in Equation (27), the emission ratio of each emission component is calculated, and the emission ratio and the emission quantum yield of the sample to be measured are calculated. By calculating the product of the rates Φ PLQY, the quantum yield _Φm of each emission component can be calculated.

<Measurement data analysis program for luminescence intensity attenuation>
Next, the program of the present invention will be explained.
The program of the present invention is a measurement data analysis program of luminescence intensity attenuation that executes the analysis method of the present invention.
For details of the analysis method of the present invention, the description in the above section <Method for analyzing measurement data of luminescence intensity attenuation> can be referred to. For an example of the steps constituting the program, the description in the above [Embodiment of analysis method] column can be referred to.

<Luminescence intensity measuring device>
The luminescence intensity measuring device of the present invention has a measurement unit capable of measuring luminescence intensity attenuation including a plurality of luminescence components, and an analysis unit that analyzes the measurement data obtained by the measurement unit by the analysis method of the present invention. It is.
For details of the analysis method of the present invention, the description in the above section <Method for analyzing measurement data of luminescence intensity attenuation> can be referred to.
The measurement unit may be any device that can measure the time-resolved spectrum of luminescence, and for example, a commercially available luminescence lifetime measurement device (eg, Hamamatsu Photonics: Quantauras Tau) or a streak camera can be appropriately selected and used.

EXAMPLES The characteristics of the present invention will be described more specifically below with reference to examples and comparative examples. Measurement data to be analyzed, calculation formulas and procedures used for analysis, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the specific examples shown below.

FIG. 5 shows the results of analyzing the measured data of luminescence intensity attenuation containing two kinds of luminescence components using an exponentially modified Gaussian function. 6 and 7 show the results of analysis using the modified Gaussian function.
The quantum yield Φ _PF obtained from the measurement data of the streak camera according to the conventional method was significantly different from the quantum yield Φ _PF obtained by analyzing the measurement data of Quantaurus Tau (Fig. 8). Therefore, the quantum yield Φ _PF obtained by analyzing the streak camera measurement data was close to the quantum yield Φ _PF obtained by analyzing the Quantaurus Tau measurement data. Also, in the fitting method, the conventional method can be fitted with two exponential functions with certainty, whereas the fitting according to the present invention clearly includes three exponential function decays. In addition, when the decay rate constant k is analyzed in detail, the analysis result kd1 of the streak camera data measured in a vacuum and the analysis result kd2 of the Quantaurus Tau data measured under an inert gas stream show similar values. Since the attenuation component corresponding to kd2 was not found in the analysis results of the Tau data, it was found that the Quantaurus Tau data were actually affected by residual oxygen. As described above, according to the analysis method of the present invention, detailed analysis can be performed using data of luminescence attenuation measurement obtained from different devices.

According to the analysis method of the present invention, the quantum yield, emission ratio, etc. of a plurality of luminescence components, such as the immediate fluorescence component and the delayed fluorescence component of the delayed fluorescence material, can be more accurately calculated in a simple process. . Therefore, the analysis method of the present invention can be effectively used for research and development of luminescent materials that emit a plurality of luminescent components, and has high industrial applicability.

Claims (10)

A method for analyzing measured data of luminescence intensity decay containing a plurality of luminescence components, comprising:
A method comprising fitting with an exponentially modified Gaussian function. 2. The method of claim 1, wherein the exponentially modified Gaussian function is represented by equation (1) below.

3. A method according to claim 1 or 2, wherein the luminescence fraction of each luminescence component is derived. A method according to any one of claims 1 to 3, wherein a rate constant for luminescence is derived. 5. The method according to any one of claims 1 to 4, wherein the plurality of luminescent components include an immediate fluorescence component and a delayed fluorescence component from a delayed fluorescence material. 6. The method according to claim 5, wherein the measured data of luminescence intensity attenuation is fitted by the following formula (11).

The emission ratio (S _PF ) of the delayed fluorescence component to the total emission of the immediate fluorescence component of the delayed luminescence material is calculated by the following formula (20), and the emission ratio (S _DF ) of the delayed fluorescence component to the total emission is calculated by the following formula (21). 7. The method of claim 6, wherein

[In equations (20) and (21), A ₁ and k _p are constants controlling the slope and peak height of the immediate fluorescence component, and A ₂ and k _d are the slope and peak height of the delayed fluorescence component. is a constant that controls ] 6. The method of any one of claims 1-5, wherein the plurality of luminescent moieties is three or more luminescent moieties. A measurement data analysis program for luminescence intensity attenuation, which executes the method according to any one of claims 1 to 8. It has a measurement unit capable of measuring luminescence intensity attenuation including a plurality of luminescence components, and an analysis unit that analyzes the measurement data obtained by the measurement unit by the method according to any one of claims 1 to 8. Luminescence intensity measurement device.

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