Perovskite structure compound with direct current bias and alternating voltage resistant photosensitive dielectric property and preparation method thereof

Abstract

This invention provides a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage, and its preparation method. The compound is SmTi obtained by thoroughly mixing and sintering high-purity 4N samarium oxide, chromium oxide, titanium oxide, and other reagents at high temperature. x Cr 1‑x O3 (x = 0.02–0.06) compound. A circular sample, 8 mm in diameter and approximately 1 mm thick, was prepared under 33 MPa pressure, sintered again at 1400 °C for 12 hours, and then cooled to room temperature. Semi-transparent gold films were magnetron sputtered onto both sides of the sample as measuring electrodes. A halogen visible light lamp was used as the light source, with single-source, single-sided illumination; the light intensity on the sample surface was adjustable, up to a maximum of 200 mW / cm². 2 Tested under alternating voltage (0.1V~1.0V) and DC bias (-10V~10V) conditions in both dark and light environments, with voltages ranging from 100 to 100. 6 The optical dielectric constant and loss were analyzed. The rate of change of the optical dielectric constant was calculated. In the low-frequency range of 100–1000 Hz, the optical dielectric constant increases sharply, with a rate of change reaching 500%, while the loss tangent decreases. These optical dielectric properties remain unchanged regardless of DC bias or alternating voltage, exhibiting excellent voltage resistance. These characteristics indicate that this novel oxide has broad application prospects in electronic technology and optoelectronic engineering.

Description

Technical Field

[0001] This invention relates to compounds with excellent photosensitive dielectric response characteristics in the field of electronic materials and their preparation methods, particularly a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage and its preparation method. Background Technology

[0002] Capacitors are crucial components in modern electronics, with a wide range of applications. From household appliances and transportation infrastructure to communications, manufacturing, public works, aerospace, and even defense, capacitors play a vital role. Dielectric materials, as a key component of capacitors, directly determine their quality. Therefore, the development of dielectric materials with superior physical properties has been a major research topic for many researchers. Currently, electronic devices are increasingly moving towards miniaturization, high integration, and superior performance. Existing dielectric materials can no longer meet the practical application requirements of the electronics industry. There is an urgent need to develop new dielectric materials with superior dielectric properties (high dielectric strength, low loss, and excellent frequency and environmental stability), as well as dielectric materials with entirely new properties such as optically controllable, acoustically controllable, and even magnetically controllable dielectrics. Although photosensitive properties fall under the categories of electrical conductivity and electrical transport, while dielectric properties, strictly speaking, fall under the category of insulation, research on the low-frequency dielectric properties of light modulation hides many unknown mysteries behind seemingly contradictory and opposing phenomena. It is not simply a matter of photocurrent generation. A large number of scientists and engineers are still dedicated to exploring the phenomena and mechanisms of photoinduced dielectric response. Summary of the Invention

[0003] The purpose of this invention is to provide a transition metal oxide compound that exhibits excellent low-frequency photoinduced dielectric constant increase and loss reduction characteristics at room temperature, and also exhibits excellent photosensitive dielectric properties withstanding DC bias and alternating voltage.

[0004] To achieve the above objectives, this invention proposes a method for preparing a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage, specifically as follows:

[0005] Step 1: Perovskite-structured compound SmTi x Cr 1-x O3 (x = 0.02–0.06) samples were synthesized using a high-temperature solid-state reaction method. Using an electronic balance with an accuracy of 0.0001 g, 99.99% pure samarium oxide, chromium oxide, and titanium oxide were precisely weighed according to atomic ratios and chemical dosages to obtain a mixed oxide with an atomic ratio of Sm:Ti:Cr = 1:x:(1-x).

[0006] Step 2: Place the weighed three oxide powders in an agate mortar and grind them by hand for about 1 hour, or ball mill them with anhydrous ethanol for 3 hours, ensuring thorough mixing. Then, sinter them in a high-temperature furnace for 10 hours (sintering temperature 1400℃). Afterward, grind the powder to approximately 800 mesh under the same conditions, and sinter again. Repeat the grinding and sintering process three times to ensure complete reaction. (This process of reacting solid powders at high temperatures multiple times constitutes a solid-phase reaction.)

[0007] Step 3: Finally, grind the calcined compound again, as in Step 2. Weigh a certain amount of powder and place it into a tableting mold. Press the powder into a tablet using a tablet press to prepare a disc with a diameter of 8 mm and a thickness of approximately 1.0–1.2 mm. Sinter the disc in a furnace at 1450 °C for 12 hours, then cool at a rate of 3 °C / min. The resulting disc is a disc.

[0008] Step 4: At a commercial analytical testing center, the crystal structure of the prepared sample disc was characterized using X-ray diffraction; the surface morphology and microstructure of the sample disc were examined using scanning electron microscopy.

[0009] Step 5: A semi-transparent gold film approximately 30 nm thick is magnetron sputtered on both sides of the sample disc as measuring electrodes. The two electrodes are connected to leads of the impedance analyzer 6500B using silver adhesive. Parameters such as dielectric constant, loss, and frequency are set. The correlation between the dielectric constant and dielectric loss of the sample disc and frequency is measured. The test frequency range is from 100 Hz to 1 MHz, and the test temperature is room temperature. Tests can be performed in both dark and light conditions. The light source is a low-voltage white light source (built-in 12V, 100W halogen lamp) manufactured by Changchun Optical Instrument Factory. The brightness of the light source is controlled by a switch, and the light intensity is adjusted by the distance.

[0010] The advantages and beneficial effects of this invention are as follows: Most existing photoresponse dielectric materials require higher frequency and energy ultraviolet light or even lasers as light sources, and conventional visible light lamps are rarely used. Furthermore, near room temperature, it is difficult for existing dielectric materials to achieve a 100% increase in photoresponse dielectric constant, especially as the dielectric loss tangent also increases, which greatly limits the practical application of these photoresponse dielectric materials. In this invention, the perovskite-structured compound SmTi... x Cr 1-x O3's dielectric constant under visible light can increase by more than 300% (up to about 500%) in the low-frequency range, and its dielectric loss tangent decreases, making it an ideal and practical material for optically controllable capacitors. Attached Figure Description

[0011] Figure 1 It is SmTi 0.05 Cr 0.95 O3 X-ray diffraction pattern.

[0012] Figure 2 This is a scanning electron microscope (SEM) image of the sample surface.

[0013] Figure 3 This is a schematic diagram of the sample electrode and light irradiation experiment.

[0014] Figure 4 It is 100 to 10 in both dark and light conditions. 6 Hz dielectric constant and loss.

[0015] Figure 5 These are the dielectric constants and losses at 100Hz, 500Hz, 1kHz, and 5kHz under different alternating voltages (0.1V to 1.0V) in both dark and light conditions.

[0016] Figure 6 These are the dielectric constants and losses at 100Hz, 500Hz, 1kHz, 5kHz, and 10kHz under DC bias (-10V to 10V) in both dark and light conditions. Detailed Implementation

[0017] 1. Using an electronic balance with an accuracy of 0.0001g, 99.99% pure samarium oxide, chromium oxide, and titanium oxide were precisely weighed according to atomic ratios and chemical dosages using different stoichiometry methods. SmTi was then produced by high-temperature sintering using a solid-state reaction method. x Cr 1-x O3 (x = 0.02–0.06) samples;

[0018] 2. Preparation of SmTi by three-cycle sintering x Cr 1-x O3 (x = 0.02~0.06) powder was used to make a round cake sample with a diameter of 8 mm and a thickness of about 1 mm by applying a pressure of 33 MPa. The sample was then sintered again at 1400℃ for 12 hours and then cooled to room temperature.

[0019] 3. Figure 1 The X-ray diffraction pattern shows that after SmCrO3 is doped with 2% to 6% Ti ions at an atomic ratio, the lattice structure of the material is basically the same as that of SmCrO3, which is a perovskite structure. Figure 2 The image is a scanning electron microscope (SEM) image showing the surface morphology of the prepared sample disc, indicating that the surface of the disc is dense, the grain size is between 1 and 3 micrometers, and there are a few pores.

[0020] 4. A semi-transparent gold thin film is magnetron sputtered onto both sides of the sample as measuring electrodes. Aluminum wires are bonded with silver paste. The light source is placed on one side of the sample. Figure 3 As shown. Halogen visible light is used as the light source, with single-source, single-sided illumination. The light intensity on the sample surface is adjustable, with a maximum of 200 mW / cm². 2(Reaching the surface of the gold electrode).

[0021] 5. Test the changes in dielectric constant and loss with frequency under both dark and light conditions, in the frequency range of 100–1000 Hz. 6 Hz. Figure 4 It is 100 to 10 in both dark and light conditions. 6 In the low-frequency range of 100-1000Hz, the optical dielectric constant increases sharply, and the rate of change decreases with increasing frequency. At the same time, the loss tangent decreases, and a loss peak appears near 5000Hz.

[0022] 6. Test the changes in dielectric constant and loss with alternating voltage (0.1V~1.0V) at frequencies of 100Hz, 500Hz, 1kHz, and 5kHz under dark and light conditions, respectively. Figure 5 These are the dielectric constants and losses at 100Hz, 500Hz, 1kHz, and 5kHz under different alternating voltages (0.1V to 1.0V) in both dark and illuminated conditions. These photodielectric properties do not change with alternating voltage, exhibiting excellent resistance to alternating voltage.

[0023] 7. Test the changes in dielectric constant and loss with DC bias (-10V to 10V) at frequencies of 100Hz, 500Hz, 1kHz, 5kHz, and 10kHz under both dark and light conditions. Figure 6 These are the dielectric constants and losses at 100Hz, 500Hz, 1kHz, 5kHz, and 10kHz under DC bias (-10V to 10V) in both dark and light conditions. These photodielectric properties do not change with DC bias, exhibiting excellent DC voltage resistance.

[0024] 8. Calculate the rate of change of the photoelectric dielectric constant (ε′) 光 -ε′ 黑 ) / ε′ 黑 Calculations show that in the low-frequency range of 100–1000 Hz, the photodielectric constant increases sharply, with a maximum rate of change reaching 500%, while the loss tangent decreases. These photodielectric properties do not change with DC bias or alternating voltage, exhibiting excellent voltage resistance. These characteristics indicate that this novel oxide has broad application prospects in electronic technology and optoelectronic engineering.

Claims

1. A method for preparing a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage, characterized in that, The steps include the following: Step 1: Perovskite-structured compound SmTi x Cr 1-x O3 samples were synthesized using a high-temperature solid-state reaction method, where x = 0.02~0.

06. Using an electronic balance with an accuracy of 0.0001g, 99.99% high-purity samarium oxide, chromium oxide, and titanium oxide were precisely weighed according to atomic ratio chemical dosage to obtain a mixed oxide with an atomic ratio of Sm : Ti : Cr = 1 : x : (1-x). Step 2: Place the weighed three oxide powders in an agate mortar and grind them by hand for 1 hour or add anhydrous ethanol and ball mill for 3 hours to ensure thorough mixing. Then place them in a high-temperature furnace and sinter for 10 hours at a sintering temperature of 1400 ℃. After that, grind the powder to 800 mesh under the same conditions and sinter again. The grinding and sintering process is repeated 3 times in total to ensure a full reaction. Step 3: Finally, grind the calcined compound again, just like in Step 2; weigh a certain amount of powder and put it into a tableting mold, press it into a tablet using a tableting machine, sinter it in a furnace at 1450℃ for 12 hours, and then cool it at 3℃ / min; after calcination, a disc with a diameter of 8 mm and a thickness of 1.0~1.2 mm is obtained.

2. The method for preparing a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage according to claim 1, characterized in that: The crystal structure of the prepared sample discs was characterized using X-ray diffraction; the surface morphology and microstructure of the sample discs were examined using scanning electron microscopy.

3. The method for preparing a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage according to claim 1, characterized in that: Semi-transparent gold films, sputtered to 30 nm thickness, were used as measuring electrodes on both sides of the sample disc. Wires were bonded with silver adhesive and connected to the lead-out electrodes of the impedance analyzer 6500B. Dielectric constant, loss, and frequency parameters were set to detect the correlation between the dielectric constant and dielectric loss of the sample disc and the frequency. The test frequency range was from 100 Hz to 1 MHz, and the test temperature was room temperature.

4. The method for preparing a perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage according to claim 3, characterized in that: The tests were conducted in both dark and light conditions. The light source used was a low-voltage white light source manufactured by Changchun Optical Instrument Factory, with a built-in 12V, 100W halogen lamp. The brightness of the light source was controlled by a switch, and the light intensity was adjusted by moving the light source closer to the target location.

5. A perovskite-structured compound with photosensitive dielectric properties resistant to DC bias and alternating voltage, characterized in that: It was prepared by the method described in claim 1.

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