Innovation In High Performance Electro-Chromic Device Manufacturing Method

Abstract

The invention relates to the manufacturing method of high performance electro-chromic devices containing transition metal oxide based compounds, wherein it comprises the steps of enlarging of the metal contact with Pt (Platinum) (1) sputtering method on one edge of the 80-150 nm thick Indium-Tin oxide alloy (ITO) (2), which was previously enlarged on the glass (3) by the sputter method, growing vertical nano-wall structures at 15-25 mTorr, 300-500° C. substrate temperature and at 3-45 minutes intervals on glass (3) with sputter method, by using transition metal chalcogen targets on previously enlarged ITO (2) with a thickness of 80-150 nm, oxidizing the grown structures in the oxidizing furnace for 10-60 minutes under oxygen gas in the temperature range 300-450° C., preparing the electro-chromic device by placing a counter glass/ITO (80-150 nm) in propylene carbonate (PC) to face 1 Mole/Liter Lithium perchlorate (LiClO4) ion-conducting electrolyte (6) with a 0.5-1 mm distance between them and closing it.

Claims

1. The invention relates to the manufacturing method of high performance electro-chromic devices containing transition metal oxide based compounds, wherein it comprises the following steps; Growing of the metal contact with Pt (Platinum) (1) sputtering method on one edge of the 80-150 nm thick Indium-Tin oxide alloy (ITO) (2), which was previously grown on the glass (3) by the sputter method, to preserve the conductivity of ITO during oxidation, Growing vertical nano-wall structures at 15-50 mTorr, 200-500° C. substrate temperature and at 1-45 minutes intervals on glass (3) with sputtering method, by using transition metal chalcogen targets on previously grown ITO (2) with a thickness of 80-150 nm, Oxidizing the grown structures in the oxidizing furnace for 5-120 minutes under oxygen gas controlled with mass flow controller between 100-1000 sccm in the temperature range 300-400° C., Preparing the electro-chromic device by placing a counter glass/ITO (80-150 nm) in propylene carbonate (PC) to face 1 Mol/Liter Lithium perchlorate (LiClO.sub.4) ion-conducting electrolyte (6) with a 0.5-1 mm distance between them and closing it.

2. The electro-chromic device manufacturing method according to claim 1, wherein the transition metal chalcogens used on ITO (2) are tungsten disulfide (4) (WS.sub.2) and molybdenum disulfide (MoS.sub.2).

3. The electro-chromic device manufacturing method according to claim 1, wherein FTO (fluorine doped Tin Oxide Alloy) with a thickness of 80-150 nm is used at the sputtering stage instead of Indium-Tin Oxide Alloy (ITO) (2) with a thickness of 80-150 nm.

4. The electro-chromic device manufacturing method according to claim 1, wherein using Cs-based and Na-based electrolytes is used instead of lithium perchlorate (LiClO.sub.4) ion conductive electrolyte (6).

5. This invention is a high performance electro-chromic device manufacturing method, wherein it comprises a glass (3)/ITO (2)/electro-chromic layer that allows Li ions from ion conductive electrolyte (LiClO.sub.4) (6) to enter the transition metal oxide layer to produce high performance.

6. The electro-chromic device mentioned in claim 5, wherein the transition metal oxide layer comprises transition metal oxides.

7. The electro-chromic device mentioned in claim 5, wherein the transition metal oxide layer preferably comprises WO.sub.3 (5) and MoO.sub.3.

Description

DRAWINGS TO HELP UNDERSTAND THE INVENTION

[0016] FIG. 1 illustrates the steps of the electro-chromic device manufacturing method, which is the subject of the invention.

[0017] FIG. 2 is the perspective view of the electro-chromic device, which is the subject of the invention.

DESCRIPTION OF PART REFERENCES

[0018] 1. Pt [0019] 2. ITO [0020] 3. Glass [0021] 4. WS.sub.2 [0022] 5. WO.sub.3 [0023] 6. Ion conductive electrolyte (LiCI04)

DETAILED DESCRIPTION OF THE INVENTION

[0024] In this detailed description, the preferred embodiments for the electro-chromic device manufacturing method of the invention are described for the sole purpose of providing a better understanding of the subject.

[0025] The subject of the invention involves the manufacturing of vertical nano-wall WO.sub.3 (Tungsten trioxide) (5) and MoO.sub.3 (Molybdenum trioxide) structures with an original method using the sputtering method, which is a coating method suitable for the industry, together with thermal oxidation method. With the usage of these two conventional method together, It becomes possible to produce of electro-chromic materials with nano structures with very large surface areas. It has been possible to manufacture WO.sub.3 (5) based electro-chromic devices with turn on/off time shorter than 5 s, which can work thousands of hours that have coloration efficiency in the order of 60%.

[0026] The production stages of the specially produced chromic layers such as WO.sub.3 (5), MoO.sub.3 and the device, which provide for the high performance operation of the constructed electro-chromic devices, are explained step by step below;

[0027] First, the metal contact is enlarged with Pt (Platinum) (Al would be also possible for this layer) (1) sputtering method on one edge of the 80-150 nm thick ITO (Indium-Tin oxide alloy) (2), which was previously grown on the glass (3) by the sputter method. Glass (3) and ITO (2) electrodes are used as counter electrodes in electro-chromic devices. At this point, these electro-chromic devices can also be produced using 80-150 nm FTO (fluorine doped Tin Oxide alloy).

[0028] Then, by using sputter method, transition metal chalcogens (WS.sub.2 (Tungsten disulfide) (4), Molybdenum disulfide (MoS.sub.2) etc.) were used on ITO (2) with a thickness of 80-150 nm, which were previously grown on glass (3) to grow vertical nano-wall structures at 15-50 mTorr, 200-500° C. substrate temperature and at 1-45 minutes intervals.

[0029] The grown structures are oxidized in the oxidizing furnace for 5-120 minutes under oxygen gas controlled with mass flow controller between 100-1000 sccm in the temperature range 300-400° C. This temperature range varies according to the thickness of the grown material such as MoS.sub.2 and WS.sub.2 etc. In order to find out the correct oxidation time, in-situ transmission and conductivity measurements might be required, which we used in our experiments.

[0030] Afterwards, the electro-chromic device is prepared by placing a counter glass/ITO (80-150 nm) in propylene carbonate (PC) to face 1 Mol/Liter Lithium perchlorate (LiClO.sub.4) ion-conducting electrolyte (6) with a 0.5-1 mm distance between them and closing it. Li ions are contained in this ion conductive (6) solution. Also, these devices can be implemented using Cs-based, Na-based electrolytes and etc.

[0031] Glass (3)/ITO (2)/Electro-chromic layer, vertical nano wall WO.sub.3(5), MoO.sub.3 etc. is transition metal oxide layer. It allows Li ions to enter these layers to form a high performance electro-chromic device.

[0032] After the device is manufactured, a power supply is connected with Pt (1) electrodes to the glass (3)/ITO (2)/Pt (1) layer in order to operate the device. −3 V is applied to the device (it might be lower depending on the thickness of the chromic layer). After the voltage is applied, the Li.sup.+ ions in the ion conductive electrolyte (6) layer enter the glass (3)/ITO (2)/electro-chromic layer, and over time the transparent glass begins to color. With the application of +3 V to the electrodes, the colored glass becomes transparent.

[0033] The performance data of the electro-chromic device having the Glass/ITO/WO.sub.3/electrolyte/ITO/Glass structure, which was manufactured with the method comprising the subject of the patent, is shown in the figure above. This data shows the dynamic transmittance data of the electro-chromic device at 700 nm wavelength. In the first 30-second part of the figure, −3 V was applied to the electro-chromic device and it was observed that the transmittance of the device fell below 10% from the initial transmittance value. This is the coloration state of the device and the device turns black. The first 67% part of this decrease is termed as the coloration time of the device and, as seen in the figure, this time is 2.28 s. In the second 30-second part, +3 V was applied to the device and the device was made to return to its former state. The turn-on time of the device was determined as 1.28 s here. This data shows the superior performance of the device produced by the method which is the subject of the patent. Better device performances become possible by changing the thickness of the chromic layers.