Low-temperature photoluminescence multi-sample testing system

Abstract

The invention discloses a low-temperature photoluminescence multi-sample test system in the technical field of photoluminescence test.The low-temperature photoluminescence multi-sample test system comprises a lifting table and a supporting plate, the supporting plate is fixedly connected to the top of the output end of the lifting table, the side, away from the lifting table, of the supporting plate is fixedly connected with a rotary drum, and the top of the rotary drum is fixedly connected with a dial; a rotary shaft is fixedly connected to the bottom of the cold head, the rotary shaft penetrates through the scale circular ruler and extends to the bottom of the rotary drum, the scale circular ruler is fixedly connected with the outer wall of the rotary shaft, a sample column is fixedly connected to the bottom of the rotary shaft, and a plurality of fixing positions are fixedly connected to the outer wall of the sample column; the bottom of the rotary drum is detachably connected with a hollow low-temperature sample chamber, the sample column is located in the low-temperature sample chamber, and a plurality of light-transmitting mirrors are arranged on the outer wall of the low-temperature sample chamber. The method is scientific and reasonable, and the sample column capable of rotatably testing a plurality of samples is used in the low-temperature sample chamber, so that the photoluminescence testing efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of photoluminescence testing, in particular to a low-temperature photoluminescence multi-sample testing system. Background Art

[0002] Photoluminescence refers to the phenomenon that when a substance absorbs photon energy under the irradiation of light, it excites electrons to jump from the valence band to the conduction band, forming electron-hole pairs. When these excited carriers recombine, they release energy, usually in the form of photons. Photoluminescence can be divided into two types: fluorescence and phosphorescence. Fluorescence refers to the rapid return of excited electrons to the ground state and emit light after non-radiative transitions, while phosphorescence refers to the slow return of excited electrons to the ground state and emit light through spin-forbidden transitions over a long period of time. Photoluminescence is a cold luminescence process because it is not accompanied by the generation of a large amount of heat energy.

[0003] Photoluminescence has a wide range of applications in materials science, semiconductor technology, biomedical imaging and other fields. For example, in the study of semiconductor materials, photoluminescence spectroscopy can be used to analyze the material's band structure, defect state density, carrier dynamics and other properties. In the biomedical field, specific fluorescent dyes can be used to label biomolecules, and photoluminescence imaging technology can be used to observe the internal structure of cells or diagnose diseases. In addition, photoluminescence is also used for performance evaluation and optimization of optoelectronic devices such as solar cells and light-emitting diodes. However, the sample rack in the traditional cryogenic sample chamber is fixed because the system optical path is fixed, so only one sample can be tested at a time. If multiple samples need to be tested, the temperature of the cryogenic sample chamber needs to be repeatedly adjusted and the samples need to be replaced, which ultimately leads to the problem of time-consuming low-temperature testing of multiple samples, and may lead to inconsistent test conditions.

[0004] In summary, the low efficiency of sample testing in a low-temperature sample chamber has become a problem that technicians in this field need to solve urgently. Therefore, it is necessary to propose a low-temperature photoluminescence multi-sample testing system. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a low-temperature photoluminescence multi-sample testing system, which improves the photoluminescence testing efficiency by driving the low-temperature sample chamber to move and using a sample column that can rotate to test multiple samples in the low-temperature sample chamber.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a low-temperature photoluminescence multi-sample testing system comprises a lifting platform and a support plate, the support plate is fixedly connected to the top of the output end of the lifting platform, a rotating drum is fixedly connected to the side of the support plate away from the lifting platform, a dial is fixedly connected to the top of the rotating drum, a graduated circular ruler is rotatably connected to the top of the dial, a cold head is rotatably connected to the top of the graduated circular ruler, a rotating shaft is fixedly connected to the bottom of the cold head, the rotating shaft passes through the graduated circular ruler and extends to the bottom of the rotating drum, the graduated circular ruler is fixedly connected to the outer wall of the rotating shaft, a sample column is fixedly connected to the bottom of the rotating shaft, a heating coil and a plurality of fixed positions are respectively fixedly connected to the outer walls of the sample column, a hollow low-temperature sample chamber is detachably connected to the bottom of the rotating drum, the sample column is located inside the low-temperature sample chamber, a plurality of light-transmitting mirrors are opened on the outer wall of the low-temperature sample chamber, a low-temperature cavity is arranged between the rotating drum and the rotating shaft, and the low-temperature cavity and the low-temperature sample chamber are communicated with each other.

[0007] The following principles and beneficial effects are achieved by adopting the above scheme:

[0008] Basic principle: The incident excitation laser is irradiated onto the sample rotated to the corresponding position through the incident light hole, and the sample produces photoluminescence under the excitation of the laser. The luminescent signal is transmitted out of the low-temperature sample chamber through the light-transmitting mirror, and is captured by the detection probe and converted into an electrical signal for subsequent processing and analysis. The hollow low-temperature sample chamber connected to the bottom of the rotating drum provides a low-temperature test environment for the sample. The low-temperature conditions required for the sample can be maintained by cooling the low-temperature cavity and the low-temperature sample chamber through the cold head. By rotating the cold head and the sample column fixedly connected to it, different samples can be installed in multiple fixed positions on the sample column. As the shaft rotates, each sample passes through the intersection of the illumination lines in turn, thereby realizing continuous testing of multiple samples.

[0009] Beneficial effects:

[0010] 1. The present invention can complete the performance evaluation of multiple samples in one test under low temperature conditions. Through a rotatable sample column and multiple fixed positions, continuous testing of multiple samples is achieved without the need to frequently replace samples, which significantly improves the test efficiency, reduces the number of repeated settings and calibrations, and thus reduces the test cost.

[0011] 2. The present invention ensures the consistency of test conditions for different samples. In a general cryogenic system, only one sample can be tested at a time. After changing the sample, although all parameter settings are adjusted to the same as the previous sample, it is difficult to ensure the consistency of conditions and it is difficult to predict some system errors. In the present invention, all samples are tested under the same conditions, and all conditions are consistent, including the temperature uniformity of the sample chamber, the laser intensity and the position of each optical element, which ensures that the system error tends to zero.

[0012] 3. The combined use of the dial and the graduated circular ruler in the present invention provides precise angle control for the rotation of the cold head and the shaft. The precise mechanical structure and optical design ensure the accurate alignment of the light and the sample during the test, improving the accuracy and reliability of the test.

[0013] 4. The low-temperature sample chamber of the present invention provides a stable low-temperature test environment, reducing the impact of ambient temperature on the test results. It also supports the testing of samples of different sizes and shapes, and can adapt to different test requirements by replacing fixed positions and light-transmitting mirrors of different specifications.

[0014] Furthermore, it also includes an experimental box, the top of the experimental box is detachably connected to a split upper cover, the split upper cover is provided with a reserved lifting hole, the reserved lifting hole is located on the movement trajectory of the low-temperature sample chamber, an emission light exit hole is provided on the outer wall of the experimental box, a first spare incident hole is provided on the outer wall of the experimental box on the side away from the emission light exit hole, an incident light hole is provided on the outer wall between the emission light exit hole and the first spare incident hole of the experimental box, a second spare incident light hole is provided on the outer wall of the experimental box on the side away from the incident light hole, an adjustment block is fixedly connected to the bottom wall of the experimental box, the adjustment block is fixedly connected to an auxiliary bracket, a beam splitter bracket is rotatably connected to the auxiliary bracket, the beam splitter bracket is on the illumination trajectory of the incident light hole, a normal temperature test sample rack is fixedly connected to the bottom wall of the experimental box, and the normal temperature test sample rack is located at the intersection of the incident light hole, the first spare incident hole, the second spare incident light hole and the emission light exit hole.

[0015] Beneficial effect: The fixed position of the room temperature test sample holder ensures that the sample is located at the intersection of the incident light hole, the first backup incident light hole, the second backup incident light hole and the emission light exit hole. This design not only simplifies the sample placement process, but also ensures that each sample receives the same lighting conditions and detection conditions during the test, improving the repeatability and reliability of the test.

[0016] Furthermore, an incident light lens and an emitted light lens are fixedly connected to the inner bottom wall of the experimental box close to the direction of the normal temperature test sample rack, and a filter holder is fixedly connected to the inner bottom wall of the experimental box close to the direction of the emitted light exit hole. The incident light lens is located on the illumination trajectory of the incident light hole, and the emitted light lens and the filter holder are located on the illumination trajectory of the emitted light exit hole.

[0017] Beneficial effects: The test box provides a closed and controllable test environment for the entire test system, which helps to reduce external interference, such as temperature fluctuations, light scattering, etc., thereby improving the accuracy and stability of the test. The reserved lifting hole located on the motion trajectory of the low-temperature sample chamber ensures that the low-temperature sample chamber can smoothly enter and exit the test box during the rotation process while maintaining the continuity of the light path. The precise layout of the incident light hole, the emitted light exit hole, the first spare incident hole and the second spare incident hole enables the incident light to accurately irradiate the sample, and the generated photoluminescence signal can be successfully captured by the detection probe.

[0018] Furthermore, a plurality of light shielding plates are fixedly connected to the two inner side walls of the experimental box close to the incident light hole.

[0019] Beneficial effects: The main function of the light shield is to block and reduce unnecessary light scattering and interference. In photoluminescence testing, precise control of incident light and detection light path is crucial. The light shield ensures that only precisely adjusted incident light can illuminate the sample, while reducing light reflection and scattering inside the test chamber, thereby improving the accuracy of the test and the signal-to-noise ratio.

[0020] Furthermore, the sample column is in the shape of a square column.

[0021] Beneficial effect: The square column sample column has higher stability during rotation compared to other shapes. This stability helps to reduce the shaking or deviation of the sample during the test, thereby ensuring the accuracy and reliability of the test results.

[0022] Furthermore, a plurality of temperature sensors are fixed to the bottom of the rotating shaft.

[0023] Beneficial Effects: By monitoring the temperature in real time and adjusting the low temperature environment, it is possible to ensure that each sample experiences the same temperature conditions during the test, thereby improving the accuracy and repeatability of the test.

[0024] Furthermore, a sealing layer is fixedly connected to the outer wall of the bottom of the drum.

[0025] Beneficial effect: The sealing layer effectively isolates the heat exchange between the cryogenic sample chamber and the external environment, reduces the leakage of cryogenic gas, and thus ensures the stability of the temperature inside the cryogenic sample chamber. This is crucial for photoluminescence testing that requires precise temperature control, because temperature fluctuations may affect the luminescence performance of the sample.

[0026] Furthermore, a counterweight is fixedly connected to the bottom of the lifting platform.

[0027] Beneficial effect: The counterweight can significantly increase the overall weight of the lifting platform and its upper structure, thereby reducing its shaking and vibration during operation. This is crucial for test systems that require precise control of sample position and angle, as any slight shaking may affect the accuracy of the test results.

[0028] Furthermore, a plurality of handles are fixedly connected to the top of the split upper cover.

[0029] Beneficial effect: The handle design makes the test box more convenient and quick when it needs to be moved or transported. The operator can easily lift the test box and move it to the required location by the handle without relying on other transport tools or multi-person collaboration, which improves work efficiency.

[0030] Furthermore, the inner wall of the reserved lifting hole is detachably connected with a reserved lifting hole baffle.

[0031] Beneficial effect: When no sample testing or maintenance is required, the reserved lifting hole baffle can tightly close the reserved lifting hole, effectively preventing external air, dust or other impurities from entering the interior of the test box. When conducting normal temperature testing, it is more important to prevent external light from entering the interior of the test box, thereby maintaining the cleanliness and stability of the environment in the test box. This is especially important for photoluminescence experiments that require high-precision and high-cleanliness test conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is an axonometric diagram of a lifting platform according to an embodiment of the present invention.

[0033] Figure 2 It is a side cross-sectional view of a dial according to an embodiment of the present invention.

[0034] Figure 3 It is a side sectional view of a rotating drum according to an embodiment of the present invention.

[0035] Figure 4 FIG. 4 is a diagram of an experimental box according to an embodiment of the present invention.

[0036] Figure 5 It is a top sectional view of the experimental box according to an embodiment of the present invention.

[0037] The figure marks in the drawings of the specification include 1, cold head; 2, support plate; 3, lifting platform; 4, counterweight; 5, low-temperature sample chamber; 6, auxiliary bracket; 7, dial; 8, low-temperature cavity; 9, rotating shaft; 10, rotating drum; 11, graduated circular ruler; 12, light-transmitting mirror; 13, fixing position; 14, sample column; 15, handle; 16, reserved lifting hole; 17, emission light outlet hole; 18, experimental box; 19, beam splitter bracket; 20, incident light hole; 21, adjustment block; 22, incident light lens; 23, shading plate; 24, first spare incident hole; 25, room temperature test sample rack; 26, emission light lens; 27, first spare incident hole; 28, filter bracket; 29, split upper cover; 30, heating coil. DETAILED DESCRIPTION

[0038] The following is further described in detail through specific implementation methods:

[0039] The embodiment is basically as shown in the attached Figure 1 -Attached Figure 5As shown: A low-temperature photoluminescence multi-sample testing system includes a lifting platform 3, a support plate 2 and an experimental box 18. The bottom of the lifting platform 3 is fixedly connected to a counterweight 4 by bolts. The support plate 2 is fixedly connected to the top of the output end of the lifting platform 3 by bolts. The side of the support plate 2 away from the lifting platform 3 is fixedly connected to a rotating drum 10 by bolts. The top of the rotating drum 10 is fixedly connected to a dial plate 7 by bolts. The top of the dial plate 7 is rotatably matched with a scale circular ruler 11. The top of the scale circular ruler 11 is rotatably matched with a cold head 1. The bottom of the cold head 1 is fixedly connected to a rotating shaft 9 by bolts. The rotating shaft 9 passes through the scale circular ruler 11 and extends to the bottom of the rotating drum 10. The scale circular ruler 11 is fixedly connected to the outer wall of the rotating shaft 9 by bolts. 9 are respectively embedded with a plurality of temperature sensors and a square columnar sample column 14 at the bottom, and a heating coil 30 and a plurality of fixing positions 13 are respectively embedded on the outer wall of the sample column 14. The bottom of the rotating drum 10 is detachably connected with a hollow low-temperature sample chamber 5 through a screw nut. The sample column 14 is located inside the low-temperature sample chamber 5. A plurality of light-transmitting mirrors 12 are opened on the outer wall of the low-temperature sample chamber 5. A low-temperature cavity 8 is provided between the rotating drum 10 and the rotating shaft 9. The low-temperature cavity 8 and the low-temperature sample chamber 5 are communicated with each other. A sealing layer is bonded to the outer wall of the bottom of the rotating drum 10.

[0040] It also includes an experimental box 18, the top of which is detachably connected to a split upper cover 29, the top of which is respectively fixedly connected to a plurality of handles 15 and a reserved lifting hole 16 by bolts, and the inner wall of the reserved lifting hole 16 is detachably connected to a reserved lifting hole baffle by damping. The reserved lifting hole 16 is located on the motion track of the low-temperature sample chamber 5, an emission light exit hole 17 is opened on the outer wall of the experimental box 18, a first spare incident hole 24 is opened on the outer wall of the experimental box 18 away from the emission light exit hole 17, an incident light hole 20 is opened on the outer wall between the emission light exit hole 17 and the first spare incident light hole 24 on the experimental box 18, a second spare incident light hole 27 is opened on the outer wall of the experimental box 18 away from the incident light hole 20, and a plurality of light shielding plates 23 are fixedly connected to the two inner side walls of the experimental box 18 close to the incident light hole 20 by bolts. An adjustment block 21 is fixedly connected to the inner bottom wall of the experimental box 18 by bolts, and an auxiliary bracket 6 is fixedly connected to the adjustment block 21. A beam splitter bracket 19 is hinged on the auxiliary bracket 6. The beam splitter bracket 19 is on the illumination track of the incident light hole 20. A normal temperature test sample rack 25 is fixedly connected to the inner bottom wall of the experimental box 18 by bolts. The normal temperature test sample rack 25 is located at the intersection of the incident light hole 20, the first spare incident light hole 24, the second spare incident light hole 26 and the emission light exit hole 17. An incident light lens 22 and an emission light lens 26 are fixedly connected to the inner bottom wall of the experimental box 18 near the normal temperature test sample rack 25 by bolts, respectively. A filter bracket 28 is fixedly connected to the inner bottom wall of the experimental box 18 near the emission light exit hole 17. The incident light lens 22 is located on the illumination track of the incident light hole 20, and the emission light lens 26 and the filter bracket 28 are located on the illumination track of the emission light exit hole 17.

[0041] Specific implementation steps:

[0042] First, ensure that all components are firmly installed, especially the lifting platform 3, the support plate 2, the rotating drum 10, the cold head 1, the low-temperature sample chamber 5, and the various optical elements in the experimental box 18. Check the working status of the cold head 1 and the heating coil 30 connected to the refrigeration system to ensure that they can operate normally.

[0043] Then remove the reserved lifting hole baffle and the room temperature test sample rack 25, open the split upper cover 29 of the experimental box 18, paste or fix multiple samples on the sample column, and ensure that each sample is firmly fixed on the fixed position 13. Then extend the sample column 14 containing multiple samples into the experimental box 18 through the lifting platform 3, adjust the height and angle of the experimental box sample column 14, so that one of the samples is hit by the incident laser injected from the incident light hole 20 at an angle of 45 degrees, and record the height position of the sample column 14 and keep the angle position of the sample column 14 unchanged; then raise the sample column 14 through the lifting platform 3, put on the low-temperature sample chamber 5 and seal it, and finally lower the low-temperature sample chamber 5 and the sample column 14 to the height position just recorded through the lifting platform 3, prepare to start the experiment, and close the split upper cover 29 of the experimental box 18.

[0044] Start the refrigeration system, the cold head 1 cools the sample through the rotating shaft 9, the sample column 14, the low temperature cavity 8 and the low temperature sample chamber 5, and monitors the temperature sensor to ensure that the temperature reaches the predetermined value. When the temperature stabilizes, turn on the incident light source, so that the laser is irradiated onto the first sample through the incident light hole 20, the beam splitter bracket 19 and the focusing lens 22. The photoluminescence signal emitted by the sample is converted into parallel light through the parallel light lens 26, and is output from the emission light output hole 17 after passing through the filter bracket 28. Use a monochromator and a detector to receive the optical signal output from the emission light output hole 17. The above-mentioned filter bracket 28 can replace the corresponding filter according to the wavelength of the incident laser and the test light.

[0045] After the test of the first sample is completed, the incident light source is turned off. The cold head 1 is artificially rotated, for example, 90 degrees, 180 degrees or -90 degrees, so that multiple samples are aligned with the incident light in turn. The step of rotating the cold head is repeated to perform photoluminescence spectrum tests on multiple samples. After the test of all samples is completed, the rotation of the cold head 1 and the operation of the refrigeration system are stopped, and the heating coil 30 is started to accelerate the heating process of the low-temperature sample chamber 5.

[0046] When the temperature is close to room temperature, the heating coil 30 is turned off and the low temperature sample chamber 5 is allowed to fully return to temperature. After the test is completed, the experimental data is saved and the lifting platform 3 moves the low temperature sample chamber 5 out of the experimental box 18. The reserved lifting hole baffle is closed to prevent the external environment from affecting the interior of the experimental box 18.

[0047] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A low-temperature photoluminescence multi-sample testing system, characterized in that: The invention comprises a lifting platform (3) and a support plate (2), wherein the support plate (2) is fixedly connected to the top of the output end of the lifting platform (3), a rotating drum (10) is fixedly connected to the side of the support plate (2) away from the lifting platform (3), a dial (7) is fixedly connected to the top of the rotating drum (10), a graduated circular ruler (11) is rotatably connected to the top of the dial (7), a cold head (1) is rotatably connected to the top of the graduated circular ruler (11), a rotating shaft (9) is fixedly connected to the bottom of the cold head (1), the rotating shaft (9) passes through the graduated circular ruler (11) and extends to the bottom of the rotating drum (10), and the graduated circular ruler (11) is rotatably connected to the top of the cold head (1). 1) is fixedly connected to the outer wall of a rotating shaft (9), a sample column (14) is fixedly connected to the bottom of the rotating shaft (9), a heating coil (30) and a plurality of fixing positions (13) are respectively fixedly connected to the outer wall of the sample column (14), a hollow low-temperature sample chamber (5) is detachably connected to the bottom of the rotating drum (10), the sample column (14) is located inside the low-temperature sample chamber (5), a plurality of light-transmitting mirrors (12) are opened on the outer wall of the low-temperature sample chamber (5), a low-temperature cavity (8) is provided between the rotating drum (10) and the rotating shaft (9), and the low-temperature cavity (8) and the low-temperature sample chamber (5) are connected to each other.

2. The low-temperature photoluminescence multi-sample testing system according to claim 1, characterized in that: The experimental box (18) further comprises an experimental box (18), the top of which is detachably connected to a split upper cover (29), the top of which is provided with a reserved lifting hole (16), the reserved lifting hole (16) being located on the movement track of the low-temperature sample chamber (5), an emission light exit hole (17) being provided on the outer wall of the experimental box (18), a first spare incident light hole (24) being provided on the outer wall of the experimental box (18) away from the emission light exit hole (17), an incident light hole (20) being provided on the outer wall of the experimental box (18) between the emission light exit hole (17) and the first spare incident light hole (24), and a first spare incident light hole (20) being provided on the outer wall of the experimental box (18) away from the incident light hole A second spare incident light hole (27) is provided on the outer wall of one side of the experimental box (20); an adjusting block (21) is fixedly connected to the inner bottom wall of the experimental box (18); an auxiliary bracket (6) is fixedly connected to the adjusting block (21); a beam splitter bracket (19) is rotatably connected to the auxiliary bracket (6); the beam splitter bracket (19) is on the light trajectory of the incident light hole (20); a room temperature test sample rack (25) is fixedly connected to the inner bottom wall of the experimental box (18); the room temperature test sample rack (25) is located at the intersection of the incident light hole (20), the first spare incident light hole (24), the second spare incident light hole (26) and the emitted light exit hole (17).

3. The low-temperature photoluminescence multi-sample testing system according to claim 2, characterized in that: An incident light lens (22) and an emitted light lens (26) are fixedly connected to the inner bottom wall of the experimental box (18) close to the direction of the normal temperature test sample holder (25), and a filter holder (28) is fixedly connected to the inner bottom wall of the experimental box (18) close to the direction of the emitted light exit hole (17). The incident light lens (22) is located on the illumination track of the incident light hole (20), and the emitted light lens (26) and the filter holder (28) are located on the illumination track of the emitted light exit hole (17).

4. The low-temperature photoluminescence multi-sample testing system according to claim 3, characterized in that: A plurality of light shielding plates (23) are fixedly connected to the two inner side walls of the experimental box (18) close to the incident light hole (20).

5. The low-temperature photoluminescence multi-sample testing system according to claim 4, characterized in that: The sample column (14) is in the shape of a square column.

6. The low-temperature photoluminescence multi-sample testing system according to claim 5, characterized in that: A plurality of temperature sensors are fixed to the bottom of the rotating shaft (9).

7. The low-temperature photoluminescence multi-sample testing system according to claim 6, characterized in that: A sealing layer is fixedly connected to the outer wall of the bottom of the rotating drum (10).

8. The low-temperature photoluminescence multi-sample testing system according to claim 7, characterized in that: A counterweight block (4) is fixedly connected to the bottom of the lifting platform (3).

9. The low-temperature photoluminescence multi-sample testing system according to claim 8, characterized in that: A plurality of handles (15) are fixedly connected to the top of the split upper cover (29).

10. The low-temperature photoluminescence multi-sample testing system according to claim 9, characterized in that: The inner wall of the reserved lifting hole (16) is detachably connected with a reserved lifting hole baffle.

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