The present invention is related to ABX3 perovskite particles and a light valve, more specifically is related to the halide ABX3 perovskite particles and a light control valve that can control the light transmission, and such a device is preferably used for windows, lenses, or a light shutter such as a sunroof. The fascinating multifunctional smart windows exhibit promising features for a wide range of applications in buildings, airplanes, automobiles, etc. The present invention provides a new use for halide ABX3 perovskite material.
This invention presents the method to use halide ABX3 perovskite particles to control the flux of light in a light control device, or referred as a light valve. Technically, a light valve is a device that can regulate the amount of light passing through a media like a water valve that can control the water flow. Window shade can be viewed as a light valve too. However, in this invention, the light valve is referred a device which can electronically control the light transmittance, and such a device is also scientifically referred as electrochromic device. Depending on science behind an electrochromic device, it can be further classified as polymer dispersed liquid crystal (PDLC) (U.S. patent U.S. Pat. No. 3,585,381), electrochemical device (EC) (U.S. patent U.S. Pat. No. 9,581,877) and suspension particles display (SPD) (U.S. patents U.S. Pat. No. 6,606,185). Specifically, in this invention, the light valve (LV for short hereafter) is referred a device which the light transmittance can be controlled by alternating current (AC). Such a device with controllable light switching and energy-saving advantages can be used as smart windows, rear-view car mirrors, displays, and so on.
Perovskite, the name of the perovskite, was originated from the Russian geologist Perovski and originally single-pointed the calcium titanate (CaTiO3) mineral. Later, crystals with similar structures were collectively referred to as perovskites. The cell structure of the ABX3 perovskite referred to in this patent is shown in the
In 2009, the ABX3 perovskite material was first reported for solar cells (J. Am. Chem. Soc. 131, 6050-6051, 2009). “Science” rated perovskite solar cells as one of the top 10 scientific breakthroughs in 2013. In January 2018, the Swiss Federal Institute of Technology in Lausanne sets new 23.25% the world record efficiency of perovskite solar cells. In addition, the ABX3 perovskite material has potential applications in LED (Light Emitting Diodes) (Nature nanotechnology, 9: 687-692, 2014), lasers (Nature Mater., 14: 636-642, 2015), photodetectors (Adv. Materials, 30(8):1704333, 2018), memristors (Advanced Electronic Materials, 2(7): 1600100, 2016).
However, in the prior art, there is no technology involving making light valves using ABX3 perovskite materials.
Therefore, the present invention provides ABX3 perovskite particles and its application in a light valve, and discloses a new application filed of the ABX3 perovskite material.
This invention presents the method to use ABX3 perovskite particles to control the flux of light in a light control device, or referred as a light valve. The present invention provides a new use of the ABX3 perovskite material, and method to make such a material. The present invention further provides a light valve, comprising a liquid suspension having such a material of ABX3 perovskite material, which can electronically control transmission of light. More specifically, the ABX3 perovskite particles, A is at least one of Cs+, CH3NH3+, and Rb+, B is at least one of Pb2+, Ge2+, and Sn2÷, and X is at least one of Cl−, Br−, and I−. This halide ABX3 perovskite is characterized in that have a non-spherical morphology. The feature is that the halide ABX3 perovskite particles morphology is at least one of nanowires, nanorods (one-dimensional); nanosheets (two-dimensional); cuboids, irregular (three-dimensional) particles.
According to this invention, the liquid suspension, which is used as a liquid medium to suspend the ABX3 perovskite particles, comprises one or more a mineral resistive oil, a synthetic resistive oil, and a vegetable oil.
According to this invention as illustrated in
The present invention provides a new form of halide ABX3 perovskite particles and the method to use them to control the flux of light in a light control device, or referred as a light valve.
The present invention provides a new use of the ABX3 perovskite particles, and method to make such a material. The present invention further provides a light valve, comprising a liquid suspension having such a material of ABX3 perovskite particles, which can electronically control transmission of light. More specifically, the ABX3 perovskite particles, A is at least one of Cs+, CH3NH3+, and Rb+, B is at least one of Pb2+, Ge2+, and Sn2+, and X is at least one of Cl−, Br−, and I−. Sill more preferably, A is at least one of Cs+ and CH3NH3+, B is Pb2+, X is at least one of Br− and I−.
The halide ABX3 perovskite particles are characterized in that have a non-spherical morphology. The feature is that the halide ABX3 perovskite particles morphology is at least one of the nanowires, nanorods (one-dimensional); nanosheets (two-dimensional); cuboids, irregular (three-dimensional) particles.
As illustrated in
According to this invention, the liquid suspension (300), which is used as a liquid medium to suspend the ABX3 perovskite particles, comprises one or more non-aqueous, electrically resistive liquids. Such a liquid or a liquid mixture, referring as the suspension medium, can maintain the suspended ABX3 perovskite particles in gravitational equilibrium.
More specifically in this invention, the liquid suspension (300) comprises one or more a mineral resistive oil, a synthetic resistive oil and a vegetable oil. Mineral resistive oils, such as transformer oils; synthetic resistive oils, such as silicone oils, fluorocarbon organic compounds, plasticizers (such as dioctyl phthalate, dibutyl phthalate, diisobutyl phthalate, triisodecyl trimellitate (TDTM), dodecylbenzene, polybutene oil; vegetable oils, such as castor oil, soybean oil, rapeseed oil, are good liquid suspension medium. Technically, the liquid suspension medium used in the light valve of the present invention can be any liquid light valve suspension known in the art and can be formulated according to techniques well known to those skilled in the art.
According to this invention as illustrated in
As ABX3 perovskite particles are sensitive to moisture and oxygen, the two transparent electrodes sandwiched by the liquid suspension are sealed with a resistive material, such as epoxy resin, etc., which can be used to seal the sealing material around the two transparent electrodes. The light valve is driven by alternating current to adjust light transmittance, preferably 5-500V alternating current.
The invention will now be described in more detail with reference to the following examples. However, these examples are given for illustration only and are not intended to limit the scope of the present invention. All chemicals used in the examples are purchased from Sigma-Aldrich Company unless otherwise specified. In all these examples, all parts and percentages are by weight unless otherwise noted. The light transmittance and absorption spectrum of the LV device was measured by an Oceanview spectrometer.
Cs2CO3 (4.07 g) was loaded into a 250 mL, 3-neck flask along with octadecene (50 mL, ODE) and oleic acid (11.088 g), and the mixture was dried for 1 h at 120° C. and then heated under Ar to 150° C. until all Cs2CO3 reacted with oleic acid. Since Cs-Oleate precipitates out of ODE at room temperature, it has to be preheated to make it soluble before usage.
N, N-dimethylformamide (100 mL, DMF) and PbI2 2.306 (5 mmol) were loaded into a 250 mL flask. Acetate acid 4.654 g (77.5 mmol) and dodecylamine 0.797 g (4.3 mmol) were added. After complete solubilization of PbI2, 5 mL Cs-Oleate solution was added (prepared as described Example 1). Then, the hybrid solution was added into a 5 L flask along with 4200 mL toluene.
Then, centrifuge the reaction solution at 5000 G for 1.5 hours and discard the supernatant to yield the light control CsPbI3.
Then, the CsPbI3 were further dispersed with 500 mL of toluene, mixed well with shaking and sonication (referring as LCP-Example-2).
In the same manner as in Example 2, only 1.835 g of PbBr2 was used instead of 2.306 g of PbI2. A toluene mixture containing CsPbBr3 is referring as LCP-Example-3.
In the 250 ml round bottom glass flask was weighted 10 g of TDTM (triisodecyltrimellitate), and the LCP-Example-2 prepared in the Example 2 was added in portions. After thoroughly mixing by shaking, toluene was subsequently removed by a rotary evaporator for 3 hours at 80° C. to yield a LV suspension containing CsPbI3 referred as LV Suspension Example-4.
In the 250 ml round bottom glass flask was weighted 15 g of silicone oil, and the LCP-Example-3 prepared in the Example 3 was added in portions. After thoroughly mixing by shaking, toluene was subsequently removed by a rotary evaporator for 3 hours at 80° C. to yield a LV suspension containing CsPbBr3 referred as LV Suspension Example-5.
In this example, a wet thickness of 200 um of the LV Suspension-Example 4 made in Example 4 was sealed between two transparent electrodes of ITO conductive glass using epoxy resin to produce a light valve referring as LV Device-6. When no electric voltage is applied (OFF State), LV Device-6 exhibits an orange tint and light transmission is measured to be 4.7%. When it was electrically activated using 220 Volts AC at 50 Hz (ON State), the LV Device-6 turns clearer and light transmission is measured to be 25.6%.
In this example, a wet thickness of 180 um of the LV Suspension-Example 5 made in Example 5 was sealed between two transparent electrodes of ITO conductive glass using epoxy resin to produce a light valve referring as LV Device-7. When no electric voltage is applied (OFF State), LV Device-7 exhibits an orange tint and light transmission is measured to be 6.4%. When it was electrically activated using 220 Volts AC at 50 Hz (ON State), the LV Device-7 turns clearer and light transmission is measured to be 30.2%.