CN202101838U - LED internal quantum efficiency measuring device - Google Patents

Abstract

An LED internal quantum efficiency measuring device comprises an excited beam, a reference beam, a light collector, a photometer and a temperature control unit, wherein the temperature control unit controls temperature of the light collector and an LED, the excited beam excites the LED to emit light, a reference beam with stable light output is projected on the inner wall of the light collector, the light collector collects the reference beam and the emitted LED light, and a sampling joint of the photometer is arranged on the wall surface of the light collector to respectively measure emitting light power of the LED and output power of the reference beam under high temperature and low temperature conditions, thus being capable of obtaining the internal quantum efficiency of the LED. The device is suitable for measuring various types of extension materials, LED chips and LED devices.

Description

A kind of measurement mechanism of LED internal quantum efficiency

[technical field]

The utility model relates to the quantum efficiency field of measurement, is specifically related to a kind of measurement mechanism of LED internal quantum efficiency.

[background technology]

Improving light efficiency is one of focus of LED industry development, and the LED material of selecting high internal quantum efficiency is the first step of making the high light efficiency LED light fixture.Measure the internal quantum efficiency of LED material and LED and can also can use the electroluminescence method with photoluminescence method, the two is equivalence basically.The principle of measuring the LED internal quantum efficiency with photoluminescence method is summarized as follows: when energy injects active layer greater than the photon of energy gap, can produce hole-electron pair freely.Hole and electron pair radiation recombination release energy, and send photon.But not all both hole and electron (charge carrier) can both produce photon to compound, and the efficient that the hole-electron pair radiation recombination produces photon is called internal quantum efficiency.Internal quantum efficiency is the inherent characteristic of LED, the difference of material, and internal quantum efficiency is also different.The LED of commaterial, internal quantum efficiency is also inequality under the different temperature.LED under the high temperature (for low temperature); Because multiphonon process (lattice vibration) absorbs energy and Auger effect (thereby the energy of compound release is transitted to higher energy state by other charge carrier absorption); Produce non-radiation recombination, make the efficient of radiation recombination reduce.Under low temperature condition (like 100K or lower), lattice vibration and Auger effect weaken significantly, and non-radiation recombination is suppressed.Internal quantum efficiency was similar to and reached 100% this moment.Because internal quantum efficiency has dependence to temperature, we can adopt relative method to measure the internal quantum efficiency of LED at high temperature:

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\left(\mathrm{HT}\right)}}{P_{\left(\mathrm{LT}\right)}}...\left(1\right)$

Wherein, η _IQEBe internal quantum efficiency, P _(HT)Be LED output power at high temperature, P _(LT)Be LED output power at low temperatures.

Measurement mechanism commonly used at present is: the laser instrument that adopts shorter wavelength is as excitation source; Adopt object lens or prism or integrating sphere to collect emergent light; Measure the luminous power that goes out of LED under two kinds of conditions of high low temperature respectively, the two is compared and obtains relative internal quantum efficiency.Wherein, what adopt the collection of object lens or prism collection emergent light only is the luminous flux of certain solid angle scope, and very high for the mechanical stability and the beam alignment requirement of device, because the defective of beam dump may be brought than mistake to finally measuring.And with the test macro of integrating sphere as gathering-device, its refrigerating method commonly used is in integrating sphere, to be blown into nitrogen to obtain low temperature, and stability is not high on the one hand for the low temperature that the method obtained, and the integrating sphere content is prone to tangible phenomenon uneven in temperature on the other hand.What is more important in addition, because can the bigger difference variation of experience in the measuring process, the optical property of surveying instrument or other utility appliance itself is acted upon by temperature changes and also bigger variation can takes place, thereby causes the change of big measured value.Prior art can not make a distinction reading variation that is brought by measuring equipment under the high/low temperature condition and actual LED internal quantum efficiency variation.

[utility model content]

Deficiency to above-mentioned technology; The utility model aims to provide a kind of error that loss brings of both can having avoided collecting; Acquisition low temperature that again can be stable can be proofreaied and correct because the LED internal quantum efficiency test macro of the excessive caused apparatus measures error of temperature contrast simultaneously.

For achieving the above object, the utility model has adopted following technical proposal:

A kind of measurement mechanism of LED internal quantum efficiency comprises excitation beam, loads sample cell, light collector and the photometer of tested LED, it is characterized in that; Also comprise temperature conditioning unit; The reference beam that light output is stable, described sample cell is arranged on the wall opening of light collector, and the temperature of sample cell is controlled by temperature conditioning unit; Excitation beam gets into light collector and shines on the tested LED in the sample cell from the light inlet of light collector; Reference beam is radiated on the inwall of light collector through light inlet or other light inlets of being located on the light collector, on the wall of light collector, detection window is set, and the sampling port of photometer is installed on the detection window.

In the utility model, the light-measuring integrating sphere that adopts good leak tightness is as light collector, collects the light signal in the 2 π solid angle scopes of sending from LED.Integrating sphere is a reasonable light collector in the optical radiation measurement field, has the degree of stability height, and directional dependence is little, need not to aim at, and collects and loses advantages such as little.The stable reference beam of light output is set in the utility model to be radiated on the coating of integrating sphere inwall; Because under high temperature and low temperature; The light output of reference beam can not change, therefore, if under high temperature and cryogenic conditions; The reading of photometer has changed, and must be that state owing to measurement mechanism itself has taken place to change under high and low temperature environment and causes.Based on this principle, under two kinds of conditions of higher low temperature, the reading of photometer witness mark light beam calculates calibration factor, the error that the caused surveying instrument state variation of the adjustable temperature difference is brought.

The utility model can be through following technical scheme to further qualification and perfect:

The measurement mechanism of above-mentioned LED internal quantum efficiency; On the light path before the light inlet of light collector; Setting can be switched the adjustable mirror that excitation beam or reference beam get into light collector respectively through the variation of angle or position; The angle or the position of adjustable mirror are regulated by mirror actuators, if excitation beam or reference beam on same surface level, can pass through the angle of accommodation reflex mirror with excitation beam or reference beam difference lead-in light gatherer; If excitation beam and reference beam not on same surface level, can be distinguished lead-in light gatherer (as shown in Figure 1) with excitation beam or reference beam through the position and the angle of accommodation reflex mirror.

Perhaps, the optical filter with selective permeation function is set on the light path before the light inlet of above-mentioned light collector, described optical filter transmission excitation beam and reflected reference beam, or described optical filter transmission reference beam and reflect excitation beam.(as shown in Figure 2).

Perhaps, above-mentioned excitation beam and reference beam directly import optics gathering-device (as shown in Figure 3).

The measurement mechanism of above-mentioned LED internal quantum efficiency is established the temperature control chamber in the temperature conditioning unit, described light collector and sample cell all place the temperature control cavity of temperature conditioning unit.Temperature conditioning unit makes light collector stabilized uniform to obtain low temperature to whole cavity space accurate temperature controlling.

The measurement mechanism of above-mentioned LED internal quantum efficiency, excitation beam is produced by tuned laser, and the exciting light of different frequency can be set according to different LED, and set exciting light frequency is higher than the glow frequency of LED itself.And excitation beam is expanded bundle by beam expander, makes that the excitation beam intensity distributions is more even behind the expansion bundle, has increased to excite area.

The measurement mechanism of above-mentioned LED internal quantum efficiency, excitation beam is to be mapped on the tested LED greater than 5 ° incident angle is oblique, and such setting has been avoided turning back to excitation apparatus from the sample laser light reflected, has guaranteed the stability of excitation apparatus.

The measurement mechanism of above-mentioned LED internal quantum efficiency, described light collector are the integrating spheres that inwall has the uniform diffuse reflection material.

The measurement mechanism of above-mentioned LED internal quantum efficiency, temperature conditioning unit is through liquid nitrogen or liquid helium refrigeration, and liquid nitrogen temperature is 77.36K, and liquid helium temperature is 4.2K (normal atmosphere is depressed).

The measurement mechanism of above-mentioned LED internal quantum efficiency, the tuned laser of excitation beam, reference beam transmitter, photometer, mirror actuators and temperature conditioning unit all are electrically connected with control module, by control module above each several part are controlled.

Above-mentioned excitation apparatus excitation beam intensity is adjustable, and different excitation beam intensity can be set as required.

Above-mentioned photometer is spectral radiometer or radiancy meter.When photometer is the spectral radiance timing, can measure the spectral power distribution of LED emission and the spectral power distribution of reference beam, measured parameter is more complete.And, can only measure by photometer the average light output quantity in certain wave band when being radiancy meter or photometer.

Under hot conditions, be positioned at the tested LED on the integrating sphere wall with the excitation beam irradiation, the survey record sampling port is positioned at the radiative response of the photometer of integrating sphere wall to tested LED, is designated as P _{LED (HT)}, a branch of stable reference beam is imported same integrating sphere, the same photometer of survey record is designated as P to the response of reference beam _{R (HT)}

Under cryogenic conditions, shine tested LED and the same photometer of survey record to the radiative response of tested LED with excitation beam, be designated as P _{LED (LT)}, identical reference beam is imported same integrating sphere, and the same photometer of survey record is designated as P to the response of reference beam _{R (LT)}

Under lower temperature and two kinds of conditions of high temperature, photometer is to the response of reference beam, the accounting temperature calibration factor:

$K=\frac{P_{R\left(\mathrm{LT}\right)}}{P_{R\left(\mathrm{HT}\right)}}...\left(2\right)$

Under higher temperatures and two kinds of conditions of low temperature, photometer is to the radiative response of tested LED, and with the calibration of the temperature correction factor, obtains the internal quantum efficiency η of tested LED _IQE:

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}}\·K...\left(3\right)$

The state variation of measurement mechanism under high low temperature maybe be relevant with wavelength; In order to make measurement update reach better effect; Suggestion reference beam and LED emission light have same or analogous measurement wave band, use the correction factor under each wavelength to proofread and correct the radiative measured value of LED under the corresponding wavelength.Need successively record reference light and the radiative output power of LED during measurement.

Above-mentioned calibration factor can be got by following formula:

$K\left(\mathrm{\λ}\right)=\frac{P_{R\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}{P_{R\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}...\left(4\right)$

The internal quantum efficiency of LED can obtain through following formula:

${\mathrm{\η}}_{\mathrm{IQE}}\left(\mathrm{\λ}\right)=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}\·K\left(\mathrm{\λ}\right)...\left(5\right)$

Perhaps internal quantum efficiency is an integration amount, and promptly computing formula is:

${\mathrm{\η}}_{\mathrm{IQE}}\left(\mathrm{\λ}\right)=\frac{\underset{a}{\∫}{P}_{\mathrm{LED}\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)\·K\left(\mathrm{\λ}\right)\·W\left(\mathrm{\λ}\right)}{\underset{a}{\∫}{P}_{\mathrm{LED}\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)\·W\left(\mathrm{\λ}\right)}...\left(6\right)$

In the formula, a is the integration wavelength band, and W (λ) is the weighted integral function of appointment, for example, and human eye luminous efficiency function V (λ).

Suppose state variation and the Wavelength-independent of measurement mechanism under high low temperature, promptly calibration factor is a constant under a certain fixing temperature difference.This moment is not overlapping as if the spectral range of excitation beam, reference beam and LED emission optical output power, recommends witness mark light and the radiative output power of LED (like Fig. 2) simultaneously, because this can reduce Measuring Time, is convenient to improve the measurement repdocutbility.And have when overlapping when excitation beam and reference beam or reference beam and the radiative spectrum of LED, need successively witness mark light and the radiative output power of LED (like Fig. 1, Fig. 2, Fig. 3).

The measurement mechanism of above-mentioned a kind of LED internal quantum efficiency, described reference beam are the standard sourcess of broader bandwidth, or gas laser source.

In sum; The described a kind of device of measuring the internal quantum efficiency of LED of the utility model; Both can avoid collecting the error that loss brings; Can proofread and correct again owing to the excessive caused apparatus measures error of temperature contrast, described measurement mechanism is fit to measure various types of epitaxial materials and led chip and LED device.

[description of drawings]

Accompanying drawing 1 is the measurement mechanism figure of embodiment 1;

Accompanying drawing 2 is the measurement mechanism figure of embodiment 2;

Accompanying drawing 3 is the measurement mechanism figure of embodiment 3;

The 1-excitation beam; 2-LED; The 3-LED sample cell; The 4-light collector; The 5-photometer; The 6-temperature conditioning unit; The 7-reference beam; The 8-light inlet; The 9-detection window; The 10-catoptron; The 11-mirror actuators; The 12-optical filter; The 13-tuned laser; The 14-beam expander; 15-reference beam transmitter; The 16-light barrier; The 17-control module.

Embodiment

[embodiment 1]

Press Fig. 1 coupling arrangement, the device of said measurement LED internal quantum efficiency, integrating sphere 4 devices are in the cavity of temperature conditioning unit 6, and tested LED2 is placed in the integrating sphere 4 bottom sample cells 3, and photometer is a spectrometer 5, connects spectrometer 5 and integrating sphere 4.Open reference beam transmitter 15, accommodation reflex lens actuator 11 makes reference beam 7 get into integrating sphere and shine on the integrating sphere inwall spectrometer 5 witness mark light beam output power P _{R (HT)}, open tuned laser 13, accommodation reflex lens actuator 11 makes excitation beam 1 get in the integrating sphere and shines on the LED that spectrometer 5 is measured the excitation light power P of LED _{LED (HT)}

Press Fig. 1 coupling arrangement, the device of said measurement LED internal quantum efficiency, integrating sphere 4 devices are in the cavity of temperature conditioning unit 6, and tested LED2 is placed in the integrating sphere 4 bottom sample cells 3, and photometer is a spectrometer 5, connects spectrometer 5 and integrating sphere 4.Open Cryo Equipment, treat that temperature reaches target temperature after, open reference beam transmitter 15, accommodation reflex lens actuator 11 makes reference beam 7 get into integrating spheres and shine on the integrating sphere inwall spectrometer 5 witness mark light beam output power P _{R (LT)}, open tuned laser 13, accommodation reflex lens actuator 11 makes excitation beam 1 get in the integrating sphere and shines on the LED that spectrometer 5 is measured the excitation light power P of LED _{LED (LT)}

Measuring process is following:

I) under the hot conditions, open reference beam transmitter 15, accommodation reflex lens actuator 11 makes reference beam 7 get into integrating sphere and shine on the integrating sphere inwall output power P of spectrometer measurement reference beam 7 _{R (HT)}, close reference beam transmitter 15, open tuned laser 13, accommodation reflex lens actuator 11 makes excitation beam 1 get in the integrating sphere and shines on the LED, treats the radiative output power P of luminous stable back spectrometer measurement LED _{LED (HT)}

Ii) open Cryo Equipment, after waiting to reach target temperature, open reference beam transmitter 15, accommodation reflex lens actuator 11 makes reference beam 7 get into integrating sphere and shine on the integrating sphere inwall output power P of spectrometer 5 witness mark light beams _{R (LT)}, close reference beam transmitter 15, open tuned laser 13, accommodation reflex lens actuator 11 makes excitation beam 1 get in the integrating sphere and shines on the LED, treats the radiative output power P of luminous stable back spectrometer measurement LED _{LED (LT)}

Iii) suppose K and Wavelength-independent, analyze the spectroscopic data of reference light, calculate the calibration factor K of corresponding wavelength respectively, bring the radiative output power of the LED in the spectrum into formula (3), get final product the internal quantum efficiency of measured LED.

$K=\frac{P_{R\left(\mathrm{LT}\right)}}{P_{R\left(\mathrm{HT}\right)}}...\left(2\right)$

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}}\·K...\left(3\right)$

Suppose that K is relevant with wavelength, analyze the spectroscopic data of reference light, calculate the calibration factor K (λ) of corresponding wavelength respectively, bring the radiative output power of the LED in the spectrum into formula (5), get final product the internal quantum efficiency of measured LED.

$K\left(\mathrm{\λ}\right)=\frac{P_{R\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}{P_{R\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}...\left(4\right)$

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}\·K\left(\mathrm{\λ}\right)...\left(5\right)$

[embodiment 2]

Press Fig. 2 coupling arrangement, the device of said measurement LED internal quantum efficiency, integrating sphere 4 devices are in the cavity of temperature conditioning unit 6, and LED is placed in the integrating sphere bottom sample cell 3, connects spectrometer 5 and integrating sphere 4.Open reference beam transmitter 15, reference beam 7 gets into integrating sphere 4 through optical filter 12 reflections, shines on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (HT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 by catoptron 10 reflections through optical filter 12 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the high temperature _{LED (HT)}

Press Fig. 2 coupling arrangement, the device of said measurement LED internal quantum efficiency, integrating sphere 4 devices are in the cavity of temperature conditioning unit 6, and LED2 is placed in the integrating sphere 4 bottom sample cells 3, connects spectrometer 5 and integrating sphere 4.Open Cryo Equipment, after waiting to reach target temperature, open reference beam transmitter 15, reference beam 7 gets into integrating sphere 4 through optical filter 12 reflections, shines on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (LT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 by catoptron 10 reflections through optical filter 12 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the low temperature _{LED (LT)}

Its concrete measuring process is following:

I) under the hot conditions, open reference beam transmitter 15, reference beam 7 gets into integrating sphere 4 through optical filter 12 reflections, shines on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (HT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 by catoptron 10 reflections through optical filter 12 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the low temperature _{LED (HT)}

Ii) open low temperature control, after waiting to reach target temperature, open reference beam transmitter 15, reference beam 7 gets into integrating sphere 4 through optical filter 12 reflections, shines on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _(LT), close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 by catoptron 10 reflections through optical filter 12 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the low temperature _{LED (LT)}

Iii) suppose K and Wavelength-independent, analyze the spectroscopic data of reference light, calculate the calibration factor K of corresponding wavelength respectively, bring the radiative output power of the LED in the spectrum into formula (3), get final product the internal quantum efficiency of measured LED.

$K=\frac{P_{R\left(\mathrm{LT}\right)}}{P_{R\left(\mathrm{HT}\right)}}...\left(2\right)$

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}}\·K...\left(3\right)$

Suppose that K is relevant with wavelength, analyze the spectroscopic data of reference light, calculate the calibration factor K (λ) of corresponding wavelength respectively, bring the radiative output power of the LED in the spectrum into formula (5), get final product the internal quantum efficiency of measured LED.

$K\left(\mathrm{\λ}\right)=\frac{P_{R\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}{P_{R\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}...\left(4\right)$

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}\·K\left(\mathrm{\λ}\right)...\left(5\right)$

Annotate: when K and Wavelength-independent, and the tuned laser exciting light, LED launches light, when reference light three spectrum is not overlapping, can open reference beam transmitter and tuned laser simultaneously.

[embodiment 3]

Press Fig. 3 coupling arrangement, the device of said measurement LED internal quantum efficiency, integrating sphere 4 devices are in the cavity of temperature conditioning unit 6, and LED is placed in the integrating sphere bottom sample cell 3, connects spectrometer 5 and integrating sphere 4.Reference beam 7 and excitation beam 1 are opened reference beam transmitter 15 directly into injecting integrating sphere, with reference to shining on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (HT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the high temperature _{LED (HT)}

Press Fig. 3 coupling arrangement, the device of said measurement LED internal quantum efficiency, integrating sphere 4 devices are in the cavity of temperature conditioning unit 6, and LED2 is placed in the integrating sphere 4 bottom sample cells 3, connects spectrometer 5 and integrating sphere 4.Open Cryo Equipment, after waiting to reach target temperature, reference beam 7 and excitation beam 1 are opened reference beam transmitter 15 directly into injecting integrating sphere, with reference to shining on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (LT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the low temperature _{LED (LT)}

Its concrete measuring process is following:

I) under the hot conditions, open reference beam transmitter 15, reference beam 7 gets into integrating sphere 4, shines on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (HT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam gets into integrating sphere 4 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the low temperature _{LED (HT)}

Ii) open low temperature control, after waiting to reach target temperature, open reference beam transmitter 15, reference beam 7 gets into integrating sphere 4, shines on integrating sphere 4 inwalls output power P of spectrometer 5 witness mark light _{R (LT)}, close reference beam transmitter 15, open tuned laser 13, excitation beam 1 gets into integrating sphere 4 and shines on the LED2, and spectrometer 5 is measured LED exciting light output power P under the low temperature _{LED (LT)}

Iv) suppose K and Wavelength-independent, analyze the spectroscopic data of reference light, calculate the calibration factor K of corresponding wavelength respectively, bring the radiative output power of the LED in the spectrum into formula (3), get final product the internal quantum efficiency of measured LED.

$K=\frac{P_{R\left(\mathrm{LT}\right)}}{P_{R\left(\mathrm{HT}\right)}}...\left(2\right)$

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}}\·K...\left(3\right)$

Suppose that K is relevant with wavelength, analyze the spectroscopic data of reference light, calculate the calibration factor K (λ) of corresponding wavelength respectively, bring the radiative output power of the LED in the spectrum into formula (5), get final product the internal quantum efficiency of measured LED.

$K\left(\mathrm{\λ}\right)=\frac{P_{R\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}{P_{R\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}...\left(4\right)$

${\mathrm{\η}}_{\mathrm{IQE}}=\frac{P_{\mathrm{LED}\left(\mathrm{HT}\right)}\left(\mathrm{\λ}\right)}{P_{\mathrm{LED}\left(\mathrm{LT}\right)}\left(\mathrm{\λ}\right)}\·K\left(\mathrm{\λ}\right)...\left(5\right)$

Annotate: when K and Wavelength-independent, and the tuned laser exciting light, LED launches light, when reference light three spectrum is not overlapping, can open reference beam transmitter and tuned laser simultaneously.

Claims (7)

1. the measurement mechanism of a LED internal quantum efficiency; Comprise excitation beam (1), load sample cell (3), light collector (4) and the photometer (5) of tested LED (2); It is characterized in that, also comprise temperature conditioning unit (6), the reference beam (7) that light output is stable; Described sample cell (3) is arranged on the wall opening of light collector (4); The temperature of sample cell (3) is by temperature conditioning unit (2) control, and excitation beam (1) gets into light collector (4) and shines on the tested LED (2) in the sample cell (3) from the light inlet (8) of light collector (4), and reference beam (7) is radiated on the inwall of light collector (4) through light inlet (8) or other light inlets of being located on the light collector (4); Detection window (9) is set on the wall of light collector (4), and the sampling port of photometer (5) is installed on the detection window (9).

2. the measurement mechanism of LED internal quantum efficiency as claimed in claim 1; It is characterized in that; On the preceding light path of the light inlet (8) of light collector (4); Setting can be switched the adjustable mirror (10) that excitation beam (1) or reference beam (7) get into light collector (4) respectively through the variation of angle or position, and the angle of adjustable mirror (10) or position are regulated by mirror actuators (11).

3. the measurement mechanism of LED internal quantum efficiency as claimed in claim 1; It is characterized in that; Optical filter (12) with selective permeation function is set on the preceding light path of the light inlet (8) of light collector (4); Described optical filter (12) transmission excitation beam (1) and reflected reference beam (7), or described optical filter (12) transmission reference beam (7) and reflection excitation beam (1).

4. like the measurement mechanism of claim 1 or 2 or 3 described LED internal quantum efficiencies, it is characterized in that temperature conditioning unit is provided with the temperature control chamber in (6), described light collector (3) and sample cell (10) all place the temperature control cavity of temperature conditioning unit (6).

5. like the measurement mechanism of claim 1 or 2 or 3 described LED internal quantum efficiencies, it is characterized in that excitation beam (1) is produced by tunable laser (13), and expanded bundle by beam expander (14).

6. like the measurement mechanism of claim 1 or 2 or 3 described LED internal quantum efficiencies, it is characterized in that described excitation beam (1) is to be mapped on the tested LED (2) greater than the incident angle of 5 degree is oblique.

7. the measurement mechanism of LED internal quantum efficiency as claimed in claim 1 is characterized in that, described light collector (4) is the integrating sphere that inwall has the uniform diffuse reflection inside surface.

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