JP7412802B2 - Spectroscopic measurement method - Google Patents

Description

The present invention relates to a spectroscopic measurement method for spectroscopically measuring the external quantum efficiency, absorption rate, and internal quantum efficiency of a luminescent material such as a phosphor.

In order to find out the luminous efficiency of a luminescent material such as a phosphor, evaluation of the quantum efficiency of output energy with respect to input energy is widely used. Among these, the quantum efficiency value of powdered phosphors used in light-emitting devices such as white light emitting diodes (white LEDs) is important, and international standardization of measurement methods is also underway. The absorption rate and quantum efficiency of a luminescent sample are calculated using the following equation using the measured value of the number of photons.

Absorption rate is the proportion of photons absorbed by the sample among the photons emitted by excitation light. Usually, the number of photons of excitation light is measured by irradiating the excitation light onto a standard white plate, etc., and the number of photons of scattered light (number of scattered photons) is measured by irradiating the excitation light onto the sample, and the formula is Find it using (1a).

Internal quantum efficiency is the proportion of absorbed photons that are converted into internal emission. Usually, the number of photons of excitation light is measured by irradiating the excitation light onto a standard white plate, etc., and the number of photons of scattered light (number of scattered photons) is measured by irradiating the excitation light onto the sample, and the formula is The absorption rate is determined using (1a), the number of photons of fluorescence emitted by the sample is measured, and the internal quantum efficiency is determined using equation (1b). Note that in calculating the number of scattered photons, it is necessary to divide the scattered light intensity by the diffuse reflectance of the standard white sample.

External quantum efficiency is the proportion of photons of excitation light that are converted into light emission. The absorption rate is determined by formula (1a), the internal quantum efficiency is determined by formula (1b), and the external quantum efficiency is determined by the product of the absorption rate and the internal quantum efficiency by formula (1c).

A common method for measuring quantum efficiency is a method using an integrating sphere (hereinafter referred to as the integrating sphere method; see, for example, Non-Patent Document 1), and calculations are performed by acquiring a spectrum as shown in FIG. 1. The method for measuring internal quantum efficiency has been standardized using this method (ISO20351/JIS R1697).
FIG. 1 is a diagram showing exemplary emission and scattering spectra.
FIG. 2 is a schematic diagram showing a spectrometer that performs the integrating sphere method.

The internal quantum efficiency is calculated as follows using the spectrometer 200 shown in FIG.
(1) A standard diffuser white plate (not shown) is installed on the bottom of the integrating sphere 210, and the excitation light from the light source 220 is irradiated onto the standard diffuser white plate, so that the excitation light is made uniform within the integrating sphere 210. The spectrum of the spectrum is measured by the spectroscopic means 230.
(2) By installing the fluorescent substance to be measured 240 on the bottom surface of the integrating sphere 210 and irradiating the fluorescent substance to be measured 240 with excitation light, a part of the excitation light is reflected and a part of the excitation light is reflected from the fluorescent substance. is absorbed and wavelength converted.
(3) The spectrum of the mixed light of the reflected excitation light (scattered light) and the wavelength-converted fluorescence is made uniform within the integrating sphere 210 and is measured by the spectroscopy means 230.
(4) Using the measured value of the number of photons, calculate the internal quantum efficiency using equation (1b).

Another method for measuring quantum efficiency has been developed (see, for example, Non-Patent Document 2). As shown in Figure 1 of Non-Patent Document 2, by moving the detector with respect to the incidence of monochromatic light with the phosphor to be measured placed horizontally, the fluorescence and scattering from the phosphor to be measured can be detected. Performs bending angle spectroscopic measurements of light. Quantum efficiency can be measured directly by spatially integrating the fluorescence and scattered light spectra and emission intensities at various angles. Although it has the advantage of being able to directly measure the absolute value of quantum efficiency, the equipment is expensive and the measurement takes a long time.

Quantum efficiency is a good indicator during the research and development stage of light-emitting materials to determine how much efficiency they have compared to conventional products, or how much improvement is possible in the future. Furthermore, at the stage of practical application, such as for white LED applications, it is often used to determine specifications for commercial transactions of luminescent materials and to control quality in each manufacturing process. Particularly in the latter case, extremely high precision is required for quantum efficiency measurements. It goes without saying that the measurement accuracy of the emission spectrum is most important for the accuracy of the quantum efficiency, but a particularly large source of uncertainty is the energy calibration accuracy over a wide wavelength range. In light-emitting materials such as phosphors, the wavelength of excitation light that inputs energy and the wavelength of fluorescent light that is output are significantly different.

In the case of a white LED, it is often excited at a wavelength of 405 nm or 450 nm and converted into fluorescence with a wide wavelength range of 500 to 800 nm. Optical systems and spectrophotometers that use commonly used integrating spheres use a combination of many optical components, so energy calibration over a wide wavelength range like the one above requires careful consideration. Changes and changes over time are also likely to cause uncertainty in measurement accuracy. It would be preferable if the uncertainty caused by this energy calibration could be reduced.

Toshiaki Okubo, Yasuo Nakagawa, Journal of the Illuminating Society of Japan No. 95 Completed No. 8A (2011) p431 Kousei Takahashi et al., 78th Japan Society of Applied Physics Autumn Academic Conference, Proceedings 7p-A414-7

An object of the present invention is to provide a spectroscopic measurement method for spectroscopically measuring the external quantum efficiency, absorption rate, and internal quantum efficiency of a luminescent material such as a phosphor, which reduces the influence of uncertainty due to energy calibration.

In the spectroscopic measurement method according to the present invention, a standard material whose optical properties are valued is excited with excitation light from a light source, and a wavelength spectrum of light from the standard material caused by the excitation light is measured using a spectroscopic means. Exciting the target test substance with the excitation light from the light source, and using the spectroscopy means to acquire the wavelength spectrum of the measured light from the test substance caused by the excitation light. and a step of data analyzing the measured value of the test substance using the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance, and the data analysis step includes the step of analyzing the measured value of the test substance using the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance. a step of selecting at least one from the group consisting of external quantum efficiency, absorption rate, and internal quantum efficiency as the optical property to be determined, and selecting an optical property to be used from among the valued optical properties of the standard material. and a step of calculating the number of photons from each of the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance, the number of scattered photons of the standard substance and the test substance, and/or the number of scattered photons of the standard substance and the test substance. calculating the number of emitted photons of the test substance; using the valued optical properties of the selected standard substance and the calculated number of emitted photons and/or the number of scattered photons; calculating the selected optical properties of a substance, thereby solving the above problem.
In the selecting step, external quantum efficiency (η _ext-sam ) is selected as the optical property to be determined of the test substance, and external quantum efficiency (η _ext-ref ) is selected as the valued optical property of the standard substance. Alternatively, the step of selecting a combination of absorption rate (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ) and calculating the number of photons is based on the wavelength spectrum of the standard material. The steps of calculating the number of emitted photons (N _ref-em ) of the standard substance, calculating the number of emitted photons (N _sam-em ) of the test substance from the wavelength spectrum of the test substance, and calculating the optical properties , when the valued optical property of the standard material is external quantum efficiency, and when the valued optical property of the standard material is a combination of absorption rate and internal quantum efficiency, Equation (2) is executed to calculate the external quantum efficiency (η _ext-sam ) may be calculated.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)
In the selecting step, the absorbance (A _sam ) is selected as the optical property to be determined of the test substance, and the reflectance (R _sam ) or the absorption rate (A _ref ) is selected as the valued optical property of the standard substance. ) and calculating the number of photons includes calculating the number of scattered photons (N _ref-scatt ) of the standard substance from the wavelength spectrum of the standard substance, and calculating the number of scattered photons (N ref-scatt ) of the standard substance from the wavelength spectrum of the test substance. In the step of calculating the number of scattered photons (N _sam-scatt ) of the standard material and calculating the optical property, when the valued optical property of the standard material is reflectance, formula (4) is When the valued optical property is absorptance, formula (5) is executed to calculate the reflectance (R _sam ) of the test substance, and formula (6) is calculated using the reflectance of the test substance. may be executed to calculate the absorption rate (A _sam ) of the test substance.
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)
In the selecting step, the internal quantum efficiency (η _int-sam ) is selected as the desired optical property of the test substance, and the external quantum efficiency (η _ext-ref ) is selected as the valued optical property of the standard substance. Select a combination of absorption rate (A _ref ) or reflectance (R _ref ), or a combination of absorption rate (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ), and In the step of calculating the number of photons, the number of emitted photons (N _ref-em ) and the number of scattered photons (N _ref-scatt ) of the standard substance are calculated from the wavelength spectrum of the standard substance, and the number of photons emitted from the standard substance is calculated from the wavelength spectrum of the test substance. The step of calculating the number of emitted photons (N _sam-em ) and the number of scattered photons (N _sam-scatt ) of the test substance from Equation (1) is used when the value of the optical property of the standard material is a combination of absorption rate and internal quantum efficiency; When the optical property is a combination of reflectance and internal quantum efficiency, Equation (3) is executed to calculate the external quantum efficiency (η _ext-sam ) of the test substance, and the valued optical property of the standard substance is calculated. When the property is reflectance, Equation (4) is executed, and when the valued optical property of the standard substance is absorption, Equation (5) is executed to calculate the reflectance (R _{sam )} of the test substance. ), execute equation (6) using the reflectance of the test substance, calculate the absorption rate (A _sam ) of the test substance, and use the absorption rate (A _sam ) of the test substance to calculate equation (6). 7) to calculate the internal quantum efficiency (η _int-sam ) of the test substance.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)
η _int-sam = η _ext-sam /A _sam ...(7)
The light source may include a lamp selected from the group consisting of a mercury lamp, a deuterium lamp, a xenon lamp, and a halogen lamp, and a spectrometer for separating light from the selected lamp.
The spectroscopic means may acquire a wavelength spectrum in a wavelength range that includes the reflected wavelength of the excitation light and wavelengths converted by the standard substance and the test substance.
The standard substance and the test substance may be powdered phosphors.
The standard may be selected from the group consisting of β-sialon green phosphor, α-sialon orange phosphor, and CASN red phosphor.
An integrating sphere may be further used, and the standard substance and the test substance may be placed within the integrating sphere.

In the spectroscopic measurement method of the present invention, a test substance and a standard substance are each measured in the same spectrometer, and the measured values of the test substance are analyzed using the wavelength spectra obtained from each. As a result, optical properties such as quantum efficiency can be measured with high accuracy without using expensive equipment or using equipment that has not been energy calibrated. In detail, the number of photons measured in the excitation wavelength range and the number of photons measured in the emission wavelength range contribute to the calculation independently, so they are not affected by the difference in energy calibration between two separate wavelength ranges. Quantum efficiency can be obtained. Further, if the present invention is adopted, it is not necessary to measure excitation light, so the uncertainty caused by the white standard sample can be reduced and the measurement time can be shortened.

FIG. 3 is a diagram showing exemplary emission and scattering spectra. FIG. 1 is a schematic diagram showing a spectrometer that performs an integrating sphere method. 1 is a flowchart showing a spectroscopic measurement method of the present invention. It is a detailed flowchart of data analysis of step S320. It is a flowchart for calculating the external quantum efficiency of a test substance. It is a flowchart for calculating the absorption rate of a test substance. It is a flowchart for calculating the internal quantum efficiency of a test substance. FIG. 1 is a diagram schematically showing a spectrometer of the present invention. 9 is a schematic diagram showing an exemplary configuration of a data analysis device used in the spectrometer shown in FIG. 8. FIG. FIG. 2 is a schematic diagram showing an energy-calibrated oriented fluorescence spectrometry device. FIG. 3 is a diagram showing the scattering and emission spectra of sample A. FIG. 3 is a diagram showing the scattering and emission spectra of sample B. FIG. 3 is a diagram showing the scattering and emission spectra of sample C. 3 is a diagram showing a comparison between the optical properties of sample A obtained using sample B and sample C as standard substances according to Example 1, and the optical properties of sample A according to Comparative Example 1. FIG. 3 is a diagram showing a comparison between the optical properties of sample B obtained using sample A and sample C as standard substances according to example 2, and the optical properties of sample B according to comparative example 2. FIG. 3 is a diagram showing a comparison between the optical properties of sample C obtained using sample A and sample B as standard substances according to example 3 and the optical properties of sample C according to comparative example 3. FIG.

Embodiments of the present invention will be described below with reference to the drawings. Note that similar elements are given similar numbers and their explanations will be omitted.
(Embodiment 1)
In Embodiment 1, a spectroscopic measurement method of the present invention will be described.

The present inventors have been able to accurately measure optical properties such as quantum efficiency of the target test substance without using expensive equipment as shown in Non-Patent Document 2, or even using equipment that has not been energy calibrated. We have discovered an analytical method that can measure this. This will be explained with reference to the flowcharts shown in FIGS. 3 to 7.

FIG. 3 is a flowchart showing the spectroscopic measurement method of the present invention.

Step S310: A standard material whose optical properties have been valued is excited with excitation light from a light source, and a wavelength spectrum of light from the standard material caused by the excitation light (also simply called a spectrum) is determined using a spectroscopic means. get.
Step S320: The target test substance is excited with excitation light from the light source used in step S310, and the wavelength spectrum of the measured light from the test substance caused by the excitation light is determined using the spectroscopic means used in step S310. get.
Step S330: Using the wavelength spectrum of the standard substance obtained in step S310 and the wavelength spectrum of the test substance obtained in step S320, data analysis of the measured value of the test substance is performed. In this specification, "data analysis of measured values of a test substance" refers to the calculation of optical properties such as external quantum efficiency, internal quantum efficiency, absorption rate, etc. of a test substance using the wavelength spectrum of the test substance described above. intend.

By comparing and calculating the wavelength spectra obtained by measuring a standard substance and a test substance with the same measuring device (same light source and same spectroscopic means), the inventors of the present application can measure the standard material and the test substance using the device-specific wavelength. It has been found that variations in sensitivity can be reduced.

Explain in detail.
First, the standard material may have an optical property selected from the group consisting of external quantum efficiency, internal quantum efficiency, absorption rate, and reflectance. Such valuing of optical properties is performed by, for example, the apparatus shown in Non-Patent Document 2.

The standard is preferably a phosphor selected from the group consisting of beta sialon green phosphor, alpha sialon orange phosphor and CASN red phosphor. The β-sialon phosphor is, for example, the phosphor described in JP-A-2005-255895, the α-sialon orange phosphor is, for example, the phosphor described in JP-A-2005-8793, and the CASN red phosphor is, for example, , JP-A No. 2006-8721. If these phosphors are used, the above-mentioned optical properties are rated and can be measured with higher accuracy.

The standard substance and test substance used in the measurement are preferably powdered phosphors, but may also be pellets or sheets of solidified powder.

In step S310 and step S320, the wavelength spectrum acquired by the spectroscopic means includes the wavelength of excitation light converted by the sample (standard substance and test substance), and the wavelength of excitation light scattered and reflected by the sample. This is a wavelength spectrum in a wavelength range that includes the reflected wavelength of light. The comparison/calculation in step S330 is performed for each of the scattered/reflected scattered light of these wavelength spectra and the wavelength-converted fluorescence that is in a different wavelength range from the scattered light, so the measurement sensitivity due to wavelength is Variations can be reduced.

FIG. 4 is a detailed flowchart of the data analysis in step S320.

Step S410: Select at least one from the group consisting of external quantum efficiency, absorption rate, and internal quantum efficiency as the optical property to be determined for the test substance, and select the optical property to be used from the valued optical properties of the standard substance. select. For example, the external quantum efficiency may be selected as the optical property to be determined for the test substance, and the external quantum efficiency or a combination of absorption rate and internal quantum efficiency may be selected from among the valued optical properties of the standard substance. Absorptivity may be selected as the optical property to be determined for the test substance, and reflectance or absorption may be selected from among the valued optical properties of the standard substance.

Step S420: Calculate the number of photons from each of the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance. Specifically, the number of scattered photons of the standard substance and the test substance and/or the number of emitted photons of the standard substance and the test substance are calculated. The number of photons can be calculated as follows.

The number of scattered photons Ni at the i-th wavelength λi (when the spectrum is measured in 1 nm increments, the first wavelength number of the spectrum is 1, the middle is i, and the last is z) is the wavelength λi of the measured scattering spectrum. It is expressed by the following equation using the scattering intensity Wi at .
Ni=Wi×λi/(h×c)
Here, h is Planck's constant and c is the speed of light. The number N of photons for the entire wavelength can be obtained by summing all i (1st to z) photons, and is expressed by the following equation.
N=ΣWi×λi/(h×c)

Such calculation of the number of photons may be performed for each of the standard substance and the test substance. Furthermore, when calculating the emitted photons, it is sufficient to calculate the wavelengths of the respective emission spectra of the standard substance and the test substance.

The wavelength range for calculating the number of scattered photons/number of emitted photons may be manually selected by the user via an external input device (not shown), or may be selected using the intensity of the spectrum, etc. It may be set automatically.

Step S430: Using the valued optical properties of the standard material selected in step S410 and the number of emitted photons and/or the number of scattered photons calculated in step S420, the optical properties of the test substance selected in step S410 are determined. Calculate characteristics.

Steps S410 to S430 may be repeated. For example, the external quantum efficiency of the test substance may be determined in the first steps S410 to S430, and the absorption rate of the test substance may be determined in the second steps S410 to S430.

In FIG. 4, it has been explained that step S410 is performed first and then step S420 is performed, but the reverse may be possible. In this case, it is preferable to calculate both the number of scattered photons and the number of emitted photons.

In this way, the number of scattered photons measured in the excitation wavelength range in step S420 and the number of emitted photons measured in the emission wavelength range independently contribute to the calculation in step S430, so the energy between two separate wavelength ranges is It is not affected by calibration deviations. Therefore, by employing the method of the present invention, optical properties (external quantum efficiency, internal quantum efficiency, absorption rate, etc.) of a test substance can be determined with high accuracy.

Each optical property of the test substance to be determined will be explained in more detail.
(External quantum efficiency of test substance)
FIG. 5 is a flowchart for calculating the external quantum efficiency of a test substance.
Here again, calculation of the external quantum efficiency of the test substance is a specific flow of step S330, and is performed following step S320.

Step S510: In step S410 of FIG. 4, the external quantum efficiency (η _ext-sam ) is selected as the optical property to be determined for the test substance, and the external quantum efficiency (η ext-sam ) is selected as the valued optical property of the _standard substance. _ref ) or a combination of absorption (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ).

Step S520: Next, in step S420 of FIG. 4, the number of emitted photons (N _ref-em ) of the standard substance is calculated from the wavelength spectrum of the standard substance, and the number of emitted photons (N _sam- ) of the test substance is calculated from the wavelength spectrum of the test substance. _em ) is calculated. The number of emitted photons is calculated as described above.

Step S530: Next, in step S430 of FIG. 4, if the valued optical property of the standard material is the external quantum efficiency, equation (1) is used to calculate the absorption rate and the internal quantum efficiency. Equation (2) is executed in the case of a combination with quantum efficiency, and Equation (3) is executed when the valued optical property of the standard material is a combination of reflectance and internal quantum efficiency. Thereby, the external quantum efficiency (η _ext-sam ) of the test substance is calculated.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)

(absorption rate of test substance)
FIG. 6 is a flowchart for calculating the absorption rate of the test substance.
Here again, calculation of the absorption rate of the test substance is a specific flow of step S330, and is performed subsequent to step S320.

Step S610: In step S410 of FIG. 4, absorbance (A _sam ) is selected as the optical property to be determined for the test substance, and reflectance (R _sam ) or absorptance ( A _ref ).

Step S620: In step S420 of FIG. 4, the number of scattered photons of the standard substance (N _ref-scatt ) is calculated from the wavelength spectrum of the standard substance, and the number of scattered photons of the test substance (N _sam-scatt ) is calculated from the wavelength spectrum of the test substance. Calculate. The number of scattered photons is calculated as described above.

Step S630: In step S430 of FIG. 4, if the valued optical property of the standard material is reflectance, use equation (4); if the valued optical property of the standard material is absorptance, Equation (5) is executed to calculate the reflectance (R _sam ) of the test substance. Next, equation (6) is executed using the reflectance. Thereby, the absorption rate (A _sam ) of the test substance is calculated.
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)

(Internal quantum efficiency of test substance)
FIG. 7 is a flowchart for calculating the internal quantum efficiency of a test substance.
Here, too, calculation of the internal quantum efficiency of the test substance is a specific flow of step S330, and is performed following step S320.

Step 710: In step S410 of FIG. 4, the internal quantum efficiency (η _int-sam ) is selected as the optical property to be determined for the test substance, and the external quantum efficiency (η _ext -sam ) is selected as the valued optical property of the standard substance. _ref ) and absorption rate (A _ref ) or reflectance (R _ref ), or combination of absorption rate (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ). do.

Step S720: In step S420 of FIG. 4, the number of emitted photons (N _ref-em ) and the number of scattered photons (N _ref-scatt ) of the standard substance are calculated from the wavelength spectrum of the standard substance, and the number of photons of the test substance is calculated from the wavelength spectrum of the test substance. The number of emitted photons (N _sam-em ) and the number of scattered photons (N _sam-scatt ) are calculated.

Step S730: Calculate the external quantum efficiency and absorption rate of the test substance, and calculate the internal quantum efficiency of the test substance from these calculation results.

Specifically, in step S430 of FIG. 4, if the valued optical property of the standard material is the external quantum efficiency, equation (1) is used; Equation (2) is executed in the case of a combination with efficiency, and Equation (3) is executed when the valued optical properties of the standard material are a combination of reflectance and internal quantum efficiency. Thereby, the external quantum efficiency (η _ext-sam ) of the test substance is calculated.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)

When the valued optical property of the standard material is reflectance, formula (4) is executed, and when the valued optical property of the standard material is absorptance, formula (5) is executed, and the test substance The reflectance (R _sam ) of is calculated. Next, equation (6) is executed using the reflectance. Thereby, the absorption rate (A _sam ) of the test substance is calculated.
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)

Finally, equation (7) is executed using the absorption rate (A _sam ) of the test substance. In this way, the internal quantum efficiency (η _int-sam ) of the test substance is calculated.
η _int-sam = η _ext-sam /A _sam ...(7)

Note that in step S730, the absorption rate (A _sam ) of the test substance may be calculated first, and then the external quantum efficiency (η _ext-sam ) of the test substance may be calculated.

In addition, the calculation of the internal quantum efficiency of the test substance shown in Figure 7 can be obtained by formula (7) if the external quantum efficiency and absorption rate of the test substance have been calculated. The calculation of the external quantum efficiency and the absorption rate of the test substance shown in FIG. 6 may be performed, and the results may be applied to equation (7).

(Embodiment 2)
In Embodiment 2, a spectrometer that implements the spectrometry method described in Embodiment 1 will be described.

FIG. 8 is a diagram schematically showing a spectrometer of the present invention.

The spectrometer 800 includes a light source 830 that irradiates a sample 810 with excitation light 820, a spectrometer 860 that acquires wavelength spectra of light 840 and 850 emitted from the sample 810 by the irradiated excitation light 820, and a spectrometer 860 that acquires wavelength spectra of light 840 and 850 emitted by the sample 810. and a data analysis device 870 that performs data analysis on the wavelength spectrum obtained. The spectrometer 800 can irradiate a sample 810 such as a phosphor with excitation light 820 and measure and evaluate the optical properties of the sample 810 using a photoluminescence method.

The light source 830 is not particularly limited as long as it can irradiate the sample 810 and excite the sample 810, but preferably the light source 830 is selected from the group consisting of a mercury lamp, a deuterium lamp, a xenon lamp, and a halogen lamp. It may also include one selected lamp and a spectrometer that spectrally separates the light from the lamp. This allows the excitation light 820 to have a single wavelength.

The spectroscopic device 860 is a spectroscopic means that acquires the wavelength spectrum of the lights 840 and 850 emitted by the sample 810 by irradiation with the excitation light 820. In detail, the spectrometer 860 uses wavelengths in a wavelength range including the wavelength of light 840 obtained by wavelength-converting the excitation light 820 by the sample 810, and the reflection wavelength of light 850 obtained by scattering and reflecting the excitation light 820 by the sample 810. Obtain a spectrum.

The optical spectrometer 860 includes, for example, a multi-channel spectrometer (not shown) that separates the light 840 and 850 emitted by the sample 810 into wavelength components and detects the wavelength components, and a wavelength spectrum separated by the multi-channel spectrometer. It may also include a spectral data generation section (not shown) that generates data.

The generated wavelength spectrum data is configured to be output to a data analysis device 870.

The data analysis device 870 is a data analysis means that performs data analysis on the wavelength spectrum acquired by the spectrometer 860. The data analysis device 870 generates light from the standard material caused by the excitation light 820 acquired by the spectrometer 860 when a standard material whose optical properties are valued as the sample 810 is excited with the excitation light from the light source 830. and the wavelength spectrum of the light to be measured from the test substance caused by the excitation light 820 acquired by the spectrometer 860 when the test substance as the sample 810 is excited with the excitation light 820 from the light source 830. data analysis of the measured values of the test substance. With such a configuration, the inventors of the present application can accurately measure optical properties such as quantum efficiency without using expensive equipment or using equipment that has not been energy calibrated. Specific data analysis by the data analysis device 870 will be described later.

Although FIG. 8 shows a spectrometer 800 in which a sample 810 is disposed within an integrating sphere 880, the present invention is not limited thereto. If the integrating sphere 880 is used, the optical characteristics can be measured with higher precision, but the sample 810 may simply be placed in the cell without using the integrating sphere. In the present invention, optical characteristics can be measured with high precision even with a device that has not been energy calibrated. It is sufficient if the analysis device 870 is provided.

The sample 810 is preferably a powdered phosphor, but may also be a pellet or sheet of solidified powder. Further, the standard material as the sample 810 may have an optical characteristic selected from the group consisting of external quantum efficiency, internal quantum efficiency, absorption rate, and reflectance. A specific standard substance is a phosphor selected from the group consisting of β-sialon green phosphor, α-sialon orange phosphor, and CASN red phosphor, as described above. If these phosphors are used, the above-mentioned optical properties are rated and can be measured with higher accuracy.

FIG. 9 is a schematic diagram showing an exemplary configuration of a data analysis device used in the spectrometer shown in FIG. 8.

The data analysis device 870 essentially includes a selection section 910, a photon number calculation section 920, and an optical property calculation section 930, but in FIG. 9, the configuration further includes a data input section 940 and a data output section 950. shows.

The selection unit 910 selects at least one optical property to be determined of the test substance from the group consisting of external quantum efficiency, absorption rate, and internal quantum efficiency, and selects the optical property to be used from among the valued optical properties of the standard substance. This is a selection means for selecting characteristics. The desired optical properties of the test substance may be selected by a user or the like via an external input device (not shown), or may be selected in the order of external quantum efficiency, absorption rate, and internal quantum efficiency by predetermined settings. May be selected.

As will be described later, when the optical properties to be determined for the test substance are selected manually or by settings, the corresponding valued optical properties are specified. This may be performed automatically using an algorithm, or may be performed manually using an external input device (not shown). Further, the valued optical properties of the standard material may be stored in a memory or the like in advance and read out according to the settings of the selection section 910, or may be manually input using an external input device. Good too.

The photon calculation unit 920 is a photon number calculation unit that calculates the number of photons from each of the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance acquired by the spectrometer 860. Specifically, the number of photons is calculated by calculating the number of scattered photons of the standard substance and the test substance, and/or the number of emitted photons of the standard substance and the test substance.

The photon calculation unit 920 receives wavelength spectrum data from a data input unit 940 that inputs wavelength spectrum data acquired by the spectrometer 800, and calculates the number of photons.

For example, when calculating the number of scattered photons of a standard substance, the photon calculation unit 920 executes the following.

The number of scattered photons Ni at the i-th wavelength λi (when the spectrum is measured in 1 nm increments, the first wavelength number of the spectrum is 1, the middle is i, and the last is z) is the wavelength λi of the measured scattering spectrum. It is expressed by the following equation using the scattering intensity Wi at .
Ni=Wi×λi/(h×c)
Here, h is Planck's constant and c is the speed of light. The number N of photons for the entire wavelength can be obtained by summing all i (1st to z) photons, and is expressed by the following equation.
N=ΣWi×λi/(h×c)

Such calculation of the number of photons may be performed for each of the standard substance and the test substance. Furthermore, when calculating the emitted photons, it is sufficient to calculate the wavelengths of the respective emission spectra of the standard substance and the test substance.

Note that the wavelength range for calculating the number of scattered photons/number of emitted photons may be manually selected by a user or the like via an external input device (not shown), or may be selected by the photon number calculation means. It may be configured to be automatically set depending on the type of photon number.

The optical property calculating unit 930 is an optical property calculating unit 930 that calculates the selected optical property of the test substance using the valued optical property of the selected standard substance and the calculated number of emitted photons and/or number of scattered photons. It is a characteristic calculation means.

The data indicating the optical properties of the test substance calculated in this manner may be displayed on an external display device 960 via the data output unit 950, or may be output by a printing device or the like.

The selection unit 910, photon number calculation unit 920, and optical property calculation unit 930 of the data analysis device 870 are realized by, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), or the like.

Each optical property of the test substance to be determined will be explained in more detail.

(External quantum efficiency of test substance)
The selection unit 910 selects the external quantum efficiency (η _ext-sam ) as the optical property to be determined for the test substance, and selects the external quantum efficiency (η _ext-ref ) as the valued optical property of the standard substance, or Select a combination of absorption (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ).

Next, the photon number calculation means 920 calculates the number of emitted photons (N _{ref-em ) of the standard substance from the wavelength spectrum of the standard substance acquired by the spectroscopy means 860, and calculates the number of emitted photons (N ref-em} ) of the test substance from the wavelength spectrum of the test substance. N _sam-em ) is calculated. The number of emitted photons is calculated as described above.

Next, the optical property calculating means 930 uses equation (1) when the valued optical property of the standard material is the external quantum efficiency, and calculates the calculated optical property of the standard material by using the equation (1) as the absorption rate and the internal quantum efficiency. If the optical properties of the reference material are a combination of reflectance and internal quantum efficiency, then equation (3) is executed. Thereby, the external quantum efficiency (η _ext-sam ) of the test substance is calculated.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)

(absorption rate of test substance)
The selection unit 910 selects the absorption rate (A _sam ) as the optical property to be determined for the test substance, and selects the reflectance (R _sam ) or the absorption rate (A _ref ) as the valued optical property of the standard substance. do.

Next, the photon number calculation unit 920 calculates the number of scattered photons of the standard substance (N _ref-scatt ) from the wavelength spectrum of the standard substance, and calculates the number of scattered photons of the test substance (N _sam-scatt ) from the wavelength spectrum of the test substance. calculate. The number of scattered photons is calculated as described above.

Next, the optical property calculation unit 930 uses equation (4) when the valued optical property of the standard material is reflectance, and uses equation (4) when the valued optical property of the standard material is absorptance. (5) is executed to calculate the reflectance (R _sam ) of the test substance. Next, equation (6) is executed using the reflectance. Thereby, the absorption rate (A _sam ) of the test substance is calculated.
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)

(Internal quantum efficiency of test substance)
The selection unit 910 selects the internal quantum efficiency (η _int-sam ) as the optical property to be determined for the test substance, and selects the external quantum efficiency (η _ext-ref ) and absorption rate as the valued optical properties of the standard substance. (A _ref ) or reflectance (R _ref ), or a combination of absorption (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ).

Next, the photon number calculation unit 920 calculates the number of emitted photons (N _ref-em ) and the number of scattered photons (N _ref-scatt ) of the standard substance from the wavelength spectrum of the standard substance, and calculates the number of photons of the test substance from the wavelength spectrum of the test substance. The number of emitted photons (N _sam-em ) and the number of scattered photons (N _sam-scatt ) are calculated.

Next, the optical property calculation unit 930 calculates the external quantum efficiency and absorption rate of the test substance, and calculates the internal quantum efficiency of the test substance from these calculation results.

In detail, equation (1) is used when the valued optical property of the standard material is the external quantum efficiency, and when the valued optical property of the standard material is a combination of absorption rate and internal quantum efficiency. executes equation (2), and when the valued optical property of the standard material is a combination of reflectance and internal quantum efficiency, executes equation (3). Thereby, the external quantum efficiency (η _ext-sam ) of the test substance is calculated.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)

When the valued optical property of the standard material is reflectance, formula (4) is executed, and when the valued optical property of the standard material is absorptance, formula (5) is executed, and the test substance The reflectance (R _sam ) of is calculated. Next, equation (6) is executed using the reflectance. Thereby, the absorption rate (A _sam ) of the test substance is calculated.
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)

Finally, equation (7) is executed using the absorption rate (A _sam ) of the test substance. In this way, the internal quantum efficiency (η _int-sam ) of the test substance is calculated.
η _int-sam = η _ext-sam /A _sam ...(7)

Here, the optical property calculation unit 930 may first calculate the absorption rate (A _sam ) of the test substance, and then calculate the external quantum efficiency (η _ext-sam ) of the test substance, and the order does not matter. .

Calculation of the internal quantum efficiency of the test substance can be obtained by formula (7) if the external quantum efficiency and absorption rate of the test substance have been calculated. When the internal quantum efficiency is selected as the optical property to be determined, the data analysis device 870 further includes a determination unit (not shown) that determines whether the external quantum efficiency and/or absorption rate of the test substance have already been calculated. You may be prepared.

If the determination unit determines that the external quantum efficiency and absorption rate have been calculated, the optical property calculation unit 930 calculates the external quantum efficiency and absorption rate of the test substance stored in a memory etc. (not shown). Using this, equation (7) is executed.

If the determination unit determines that the external quantum efficiency has been calculated, the optical property calculation unit 930 of the data analysis device 870 calculates the absorption rate of the test substance described above, and stores the calculated absorption rate and memory, etc. Equation (7) is executed using the external quantum efficiency of the test substance stored in (not shown).

Similarly, when the determination unit determines that the absorption rate has been calculated, the optical property calculation unit 9300 of the data analysis device 87 calculates the external quantum efficiency of the test substance as described above, and and the absorption rate of the test substance stored in a memory or the like (not shown), formula (7) is executed.

The processing corresponding to the spectroscopic measurement method executed in the data analysis device 870 shown in FIGS. 8 and 9 is performed by a spectrometry program that causes a computer to perform data analysis on the wavelength spectrum acquired by the spectrometer 860, which is a spectroscopy means. realizable. That is, a spectroscopic measurement program that realizes each function of the selection section 910, photon number calculation section 920, and optical characteristic calculation section 930 related to the data analysis device 870 may be created and installed in a personal computer or the like. Furthermore, a computer-readable recording medium in which a spectrometry program is stored can also be provided. Recording media may include magnetic media such as hard disks and flexible disks, optical media such as CD-ROMs and DVD-ROMs, magneto-optical media such as floppy disks, or specially arranged to execute or store program instructions. This includes, for example, hardware devices such as RAM, ROM, and semiconductor nonvolatile memory. Moreover, the spectrometry program of the present invention may be distributed via a network without using a recording medium.

Next, the present invention will be described in detail using specific examples, but it should be noted that the present invention is not limited to these examples.

[Pricing]
First, the standard phosphor (standard material) was valued. Emission spectra of three powdered phosphor samples are measured using the optical system shown in FIG.

FIG. 10 is a schematic diagram showing an energy-calibrated oriented fluorescence spectrometer.

As standard phosphors, β-sialon green phosphor (referred to as sample A) manufactured with reference to JP-A No. 2005-255895 and α-sialon orange phosphor (referred to as sample B) manufactured with reference to JP-A-2005-8793 were used. A CaAlSiN ₃ (CASN) red phosphor (referred to as sample C) manufactured with reference to JP-A No. 2006-8721 (referred to as Sample C) was used.
Sample A = β-sialon green phosphor Sample B = α-sialon orange phosphor Sample C = CASN red phosphor

As shown in Non-Patent Document 2, a standard phosphor is irradiated with a 405 nm Xe lamp, the spectra of fluorescence and scattered light are measured while moving a multichannel spectrometer from 0° to 180°, and the emission intensity is measured. was spatially integrated and the absolute value was assigned. The assigned absolute values are shown in Table 1.

[Example 1]
In Example 1, sample A was used as the test substance, sample B and sample C were used as standard substances, and the method of the present invention was used to determine the external quantum efficiency, absorption rate, and internal Quantum efficiency was calculated.

A spectroscopic measurement device equipped with a light source, a spectroscopic device, and a data analysis device shown in FIG. 8 was used. Each sample was placed within an integrating sphere that was not energy calibrated. The light from the light source was separated into wavelengths of 405 nm, and this was used as excitation light. The spectrometer was equipped with a multichannel spectrometer. Note that since the excitation light is perpendicularly incident on the sample, the Fresnel reflection component of the glass cover placed on the top surface of the sample leaks from the excitation light port, so the influence is small. The data analysis device is equipped with a spectrometry program that can perform the processing steps described with reference to FIGS. 3 to 7.

Using the spectrometer shown in FIG. 8, wavelength spectra (scattering and emission spectra) of samples A to C were obtained (steps S310 and S320 in FIG. 3). The results are shown in FIGS. 11 to 13. Next, the measured values of sample A were analyzed using the wavelength spectrum of sample A and the wavelength spectrum of sample B or sample C (step S330 in FIG. 3).

FIG. 11 is a diagram showing the scattering and emission spectra of Sample A.
FIG. 12 is a diagram showing the scattering and emission spectra of Sample B.
FIG. 13 is a diagram showing the scattering and emission spectra of Sample C.

In Figures 11 to 13, the solid lines indicate the scattering and emission spectra, and the dotted lines indicate the scattering spectra of excitation light using a standard white plate (Spectralon grade, manufactured by Labsphere) whose reflectance is valued for the excitation wavelength. be.

In Example 1, in the data analysis (step S330 in FIG. 3), the number of scattered photons and the number of emitted photons in the wavelength spectra of samples A to C are calculated in advance (step S420 in FIG. 4), and then As the optical properties to be determined, external quantum efficiency, absorption rate, and internal quantum efficiency were sequentially selected (step S410 in FIG. 4).

The number of scattered photons (N) and the number of emitted photons (N) were calculated from the light intensity (W) of the scattering and emission spectra using the following formula.
W=N・h・c/λ
h is Planck's constant, c is the speed of light, and λ is the wavelength. In calculating the number of scattered photons, λ was set to 385 nm to 425 nm, and in calculating the emission spectrum, λ was set to 480 nm to 800 nm. Table 2 shows the number of scattered photons and the number of emitted photons of Samples A to C thus obtained.

(Calculation of external quantum efficiency)
The external quantum efficiency (η _ext-sam ) is selected as the optical property to be determined for sample A, which is the test substance, and the external quantum efficiency (η _ext-ref ) was selected (step S510 in FIG. 5). The number of emitted photons (N _sam-em /N _ref-em ) of samples A to sample C calculated previously (step S520 in FIG. 5) and the external quantum efficiency of samples B and sample C shown in Table 1 are calculated using the equation (1 ) to calculate the external quantum efficiency of sample A (step S530 in FIG. 5).
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)

(Calculation of absorption rate)
Absorption rate (A _sam ) was selected as the optical property to be determined for sample A, which is the test substance, and reflectance (R _ref ) was selected as the valued optical property of sample B and sample C, which are standard substances (Fig. 6, step S610). The number of scattered photons (N _sam-scatt /N _ref-scatt ) of samples A to sample C calculated previously (step S620 in FIG. 6) and the absorption rates of samples B and sample C shown in Table 1 are calculated using equation (5). was applied to calculate the reflectance (R _ref ) of sample A. Next, the reflectance of sample A was applied to equation (6) to calculate the absorbance of sample A (step S630 in FIG. 6).
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)

(Calculation of internal quantum efficiency)
The internal quantum efficiency (η _int-sam ) is selected as the optical property to be determined for sample A, which is the test substance, and the external quantum efficiency (η _{ext-ref )} is selected as the valued optical property of sample B and sample C, which are the standard substances. ) and the absorption rate (A _ref ) were selected (step S710 in FIG. 7). In Table 1, the number of scattered photons (N _sam-scatt /N _ref-scatt ) and the number of emitted photons (N _sam-em /N _ref-em ) (step S720 in FIG. 7) calculated previously for samples A to sample C are calculated. Using the external quantum efficiency and absorption rate of sample B and sample C shown in the table, the external quantum efficiency (η _ext-sam ) and absorption rate (A _sam ) was calculated. Next, the external quantum efficiency and absorption rate of sample A were applied to equation (7) to calculate the internal quantum efficiency of sample A (step S730 in FIG. 7).

η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)
η _int-sam = η _ext-sam /A _sam ...(7)

Table 3 and FIG. 14 show the external quantum efficiency, absorption rate, and internal quantum efficiency values of sample A obtained in this way using sample B and sample C as standard substances, respectively.
[Comparative example 1]
In Comparative Example 1, Sample A was used as the test substance, and the external quantum efficiency, absorption rate, and internal quantum efficiency of Sample A were calculated using conventional methods (Equations (1a) to (1c)). The measurement conditions were the same as in Example 1 using the spectrometer shown in FIG. However, the data analysis device 870 was not used, and a conventional method was used. Here again, the value obtained by dividing the scattering intensity of the excitation light by the diffuse reflectance of the standard white sample was used.

The number of scattered photons of sample A and the number of emitted photons of sample A used in equations (1a) to (1c) are the same as Table 2, and the number of photons of excitation light is 3.35×10 ² (1/hc )Met. The values of external quantum efficiency, absorption rate, and internal quantum efficiency of sample A obtained are shown in Table 3 and FIG. 14.

[Example 2]
In Example 2, sample B was used as the test substance, sample A and sample C were used as standard substances, and the method of the present invention was used to determine the external quantum efficiency, absorption rate, and internal Quantum efficiency was calculated. The external quantum efficiency, absorption rate, and internal quantum efficiency of Sample B were calculated in the same manner as in Example 1, except that Sample B was used as the test substance and Samples A and C were used as the standard substances. The calculated results are shown in Table 4 and FIG. 15.

[Comparative example 2]
In Comparative Example 2, Sample B was used as the test substance, and the external quantum efficiency, absorption rate, and internal quantum efficiency of Sample B were determined in the same manner as Comparative Example 1 using conventional methods (Equations (1a) to (1c)). Efficiency was calculated. The values of external quantum efficiency, absorption rate, and internal quantum efficiency of sample B obtained are shown in Table 4 and FIG. 15.

[Example 3]
In Example 3, sample C was used as the test substance, sample A and sample B were used as standard substances, and the method of the present invention was used to determine the external quantum efficiency, absorption rate, and internal Quantum efficiency was calculated. The external quantum efficiency, absorption rate, and internal quantum efficiency of Sample B were calculated in the same manner as in Example 1, except that Sample C was used as the test substance and Sample A and Sample B were used as the standard substances. The calculated results are shown in Table 5 and FIG. 16.

[Comparative example 3]
In Comparative Example 3, Sample C was used as the test substance, and the external quantum efficiency, absorption rate, and internal quantum Efficiency was calculated. The values of external quantum efficiency, absorption rate, and internal quantum efficiency of the obtained sample C are shown in Table 5 and FIG. 16.

The results of Examples 1 to 3 and Comparative Examples 1 to 3 will be summarized and explained.
In addition to the results of Examples and Comparative Examples, Tables 3 to 5 also show the absolute values (absolute measured values) of Samples A to C shown in Table 1.

FIG. 14 is a diagram showing a comparison between the optical properties of Sample A obtained using Sample B and Sample C as standard substances according to Example 1, and the optical properties of Sample A according to Comparative Example 1.
FIG. 15 is a diagram showing a comparison between the optical properties of Sample B obtained using Sample A and Sample C as standard substances according to Example 2, and the optical properties of Sample B according to Comparative Example 2.
FIG. 16 is a diagram showing a comparison between the optical properties of Sample C obtained using Sample A and Sample B as standard substances according to Example 3, and the optical properties of Sample C according to Comparative Example 3.

14 to 16 are bar graphs of Tables 3 to 5. From Tables 3 to 5 and Figures 14 to 16, the external quantum efficiency and internal quantum efficiency calculated using the conventional method of equations (1a) to (1c) are 100% for any sample. It was beyond. This is because the energy calibration of the spectrometer used was insufficient and the energy sensitivity in the fluorescence wavelength band was higher than in the wavelength band including excitation light.

On the other hand, in Examples 1 to 3, in which the spectroscopic measurement method of the present invention was carried out using the spectrometer of the present invention, the standard value of each phosphor (i.e., the absolute measurement values) were obtained. It has been shown that by employing the present invention, reliable external quantum efficiency, internal quantum efficiency, and absorption rate can be obtained even if a measurement system with insufficient energy calibration is used.

This is because the number of scattered photons measured in the excitation wavelength range and the number of emitted photons measured in the emission wavelength range independently contribute to the calculation. That is, while equation (1b) includes the number of scattered photons and the number of emitted photons at the same time, in the present invention, equations (1) to (3) include the number of emitted photons, and equations (4) to Since it is separated from the number of scattered photons in Equation (6), it is possible to reduce the influence of deviation in energy calibration between two separate wavelength ranges.

In the spectrometer and spectrometer method of the present invention, quantum efficiency and the like are calculated by separating the number of scattered photons and the number of emitted photons, but it is effective to use a standard material whose optical properties have been valued. A detailed comparison of the measurement data reveals that the closer the emission wavelength ranges of the test substance and standard substance are, the smaller the deviation from the absolute measured value. This is largely affected by energy calibration errors within the emission wavelength band. For this reason, it is desirable to use a sample with an emission wavelength band close to that of the test substance as the standard substance.

In this example, a spectrum using an integrating sphere was used, but as mentioned above, the present invention is not limited to this, and similar results can be obtained from a spectrum using a commonly used spectrophotometer. It goes without saying that quantum efficiency can be derived using this method.

In addition, in this example, the internal quantum efficiency was calculated according to the steps in FIG. 7, but using the external quantum efficiency already calculated according to the steps in FIG. 5 and the absorption rate calculated according to the steps in FIG. 7) may be executed.

INDUSTRIAL APPLICATION This invention can be utilized as a spectrometry apparatus, a spectrometry method, and a spectrometry measurement program which can be used suitably for evaluation of luminescent materials, such as a phosphor.

800 Spectrometer 810 Sample 820 Excitation light 830 Light source 840, 850 Light 860 Spectrometer 870 Data analysis device 910 Selection section 920 Photon number calculation section 930 Optical property calculation section 940 Data input section 950 Data output section 960 Display device

Claims (9)

Exciting a standard material whose optical properties have been valued with excitation light from a light source, and using a spectroscopic means to obtain a wavelength spectrum of light from the standard material caused by the excitation light;
Exciting the target test substance with the excitation light from the light source and using the spectroscopic means to obtain a wavelength spectrum of the measured light from the test substance caused by the excitation light;
Data analyzing the measured value of the test substance using the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance,
The step of analyzing the data includes:
Select at least one from the group consisting of external quantum efficiency, absorption rate, and internal quantum efficiency as the optical property to be determined for the test substance, and select the optical property to be used from among the optical properties valued for the standard substance. Steps to select and
a step of calculating the number of photons from each of the wavelength spectrum of the standard substance and the wavelength spectrum of the test substance, the step of calculating the number of photons scattered by the standard substance and the test substance, and/or the number of photons scattered by the standard substance and the test substance; a step of calculating the number of emitted photons of the substance;
calculating the selected optical property of the test substance using the valued optical property of the selected standard substance and the calculated number of emitted photons and/or number of scattered photons; Further comprising a spectroscopic measurement method. The step of selecting includes:
External quantum efficiency (η _ext-sam ) is selected as the optical property to be determined for the test substance, and external quantum efficiency (η _ext-ref ) or absorption rate ( A _ref ) or a combination of reflectance (R _ref ) and internal quantum efficiency (η _int-ref );
The step of calculating the number of photons includes:
Calculating the number of emitted photons (N _ref-em ) of the standard substance from the wavelength spectrum of the standard substance,
Calculating the number of emitted photons (N _sam-em ) of the test substance from the wavelength spectrum of the test substance,
The step of calculating the optical properties includes:
If the valued optical property of the standard material is external quantum efficiency, use equation (1); if the valued optical property of the standard material is a combination of absorption rate and internal quantum efficiency, use equation (1). (2), and when the valued optical property of the standard substance is a combination of reflectance and internal quantum efficiency, Equation (3) is executed, and the external quantum efficiency (η _ext-sam ) of the test substance is calculated. The spectroscopic measurement method according to claim 1, wherein the spectroscopic measurement method calculates .
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3) The step of selecting includes:
Selecting absorptance (A _sam ) as the optical property to be determined for the test substance, and selecting reflectance (R _sam ) or absorptance (A _ref ) as the valued optical property of the standard substance,
The step of calculating the number of photons includes:
Calculating the number of scattered photons (N _ref-scatt ) of the standard material from the wavelength spectrum of the standard material,
Calculating the number of scattered photons (N _sam-scatt ) of the test substance from the wavelength spectrum of the test substance,
The step of calculating the optical properties includes:
If the valued optical property of the standard material is reflectance, formula (4) is executed, and if the valued optical property of the standard material is absorption rate, formula (5) is executed, Calculating the reflectance (R _sam ) of the test substance,
The spectroscopic measurement method according to claim 1, wherein equation (6) is executed using the reflectance of the test substance to calculate the absorption rate (A _sam ) of the test substance.
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6) The step of selecting includes:
The internal quantum efficiency (η _int-sam ) is selected as the optical property to be determined for the test substance, and the external quantum efficiency (η _ext-ref ) and absorption rate (A _ref ) are selected as the valued optical properties of the standard substance. or a combination with reflectance (R _ref ), or a combination of absorption (A _ref ) or reflectance (R _ref ) and internal quantum efficiency (η _int-ref ),
The step of calculating the number of photons includes:
Calculating the number of emitted photons (N _ref-em ) and the number of scattered photons (N _ref-scatt ) of the standard substance from the wavelength spectrum of the standard substance,
Calculating the number of emitted photons (N _sam-em ) and the number of scattered photons (N _sam-scatt ) of the test substance from the wavelength spectrum of the test substance,
The step of calculating the optical properties includes:
If the valued optical property of the standard material is external quantum efficiency, use equation (1); if the valued optical property of the standard material is a combination of absorption rate and internal quantum efficiency, use equation (1). (2), and when the valued optical property of the standard substance is a combination of reflectance and internal quantum efficiency, Equation (3) is executed, and the external quantum efficiency (η _ext-sam ) of the test substance is calculated. Calculate,
If the valued optical property of the standard material is reflectance, formula (4) is executed, and if the valued optical property of the standard material is absorption rate, formula (5) is executed, Calculating the reflectance (R _sam ) of the test substance,
Execute equation (6) using the reflectance of the test substance to calculate the absorption rate (A _sam ) of the test substance,
The spectroscopic measurement method according to claim 1, wherein the internal quantum efficiency (η _int-sam ) of the test substance is calculated by executing equation (7) using the absorption rate (A _sam ) of the test substance.
η _ext-sam = η _ext-ref × (N _sam-em /N _ref-em )...(1)
η _ext-sam = A _ref × η _int-ref × (N _sam-em /N _ref-em ) (2)
η _ext-sam = (1-R _ref )×η _int-ref × (N _sam-em /N _ref-em )...(3)
R _sam = R _ref × (N _sam-scatt /N _ref-scatt ) (4)
R _sam = (1-A _ref )×(N _sam-scatt /N _ref-scat ) (5)
A _sam = 1-R _sam ... (6)
η _int-sam = η _ext-sam /A _sam ...(7) Claims 1 to 4, wherein the light source includes a lamp selected from the group consisting of a mercury lamp, a deuterium lamp, a xenon lamp, and a halogen lamp, and a spectrometer that spectrally specifies light from the selected lamp. The spectroscopic measurement method according to any one of. The spectroscopic measurement method according to any one of claims 1 to 5, wherein the spectroscopic means acquires a wavelength spectrum in a wavelength range that includes the reflected wavelength of the excitation light and wavelengths converted by the standard substance and the test substance. The spectroscopic measurement method according to any one of claims 1 to 6, wherein the standard substance and the test substance are powdered phosphors. The spectroscopic measurement method according to any one of claims 1 to 7, wherein the standard substance is selected from the group consisting of β-sialon green phosphor, α-sialon orange phosphor, and CASN red phosphor. The spectroscopic measurement method according to any one of claims 1 to 8, further comprising using an integrating sphere, and disposing the standard substance and the test substance within the integrating sphere.