The hottest indium tin oxide screen may be replace

Indium tin oxide screens may be replaced by silver screens

at present, emerging industries centered on information technology have started to develop and swept every land in the world. We are watching TV and using it all the time, but do you know what materials their flat-panel displays are made of? What materials are used for various board displays of various computers and electronic equipment? At present, they are all made of indium tin oxide (ITO) and their thin films. Without the display of this thin film, we can't see anything and become blind. In 2016, about 78% of the indium extracted worldwide was consumed in such products. However, in a few years, the indium tin oxide film may be replaced by the breathtaking 7Nm (nano meter) thick silver film, but in the foreseeable future, Indium tin oxide is still on your screen. At present, LED light source is also an important field of indium application

why silver film can be used in display screen

no matter what material can be used in smart screen and LCD TV screen, it must have the following key characteristics: good conductivity; Good transparency; With excellent processing formability, it can be targeted into a nano film that is incomparably thinner than cicada wings. The surface is bright and clean, and has good bendability. It can be made into various radian display screens; It will not corrode in the atmosphere and always maintain a bright surface; Friendly to the environment and harmless to human body; There are many resources, not too rare and expensive, and there is a certain market competitiveness

indium is a rare metal, but it is not too expensive or extremely scarce. In 2016, the average price in the U.S. metal market was $240.3/kg, but its supply is fixed, and there is no real main source. For example, the indium needed by the United States is imported from China and Canada. In order to get rid of this situation, since the new century, Their researchers have been looking for better and cheaper substitutes to replace indium tin oxide, but after more than ten years of research, they have not made practical achievements. Some people and companies have given up, some have gone bankrupt, and some are still working tirelessly. Hard work pays off. In 2016, they finally found a substitute of great practical value, which is ultra-thin silver film

on March 25th, 2016, the monthly journal of popular science of the United States, titled "the future screen may be made of transparent silver". A paper published by a professor of electronic engineering and computer science department of the University of Michigan in the March 2017 issue of the monthly journal advanced materials of the United States, said: using a thin silver film only 7Nm thick can be used as a display screen, which has good conductivity, Moreover, it is clear and transparent (see the 7th edition of "Reference News" on March 28, 2017). What is more valuable is that silver aluminum or silver copper alloy films have very good ductility and can be bent arbitrarily to make curved screens. Indium tin oxide does not have this ability. It is quite brittle and hard, and cannot be bent. Pure silver films are also quite brittle and hard, and cannot be made into curved screens. However, silver aluminum or silver copper alloy nano films are not only bent, but also have a very smooth surface. Guo Lingjie said, "especially in the future, more and more flexible equipment is needed, which I think may be of great use." However, y. kimisis, an associate professor of electrical engineering at Columbia University, said, "silver is an excellent material for flexible displays." But he warned that "indium tin and other phenomena called yield oxides will not be replaced soon."

properties of indium

indium (in) is a kind of rare metal. "Rare" refers to scarcity. According to the data of the United States Geological Survey (USGS), the world's Indium reserves in 2008 were 11000t, and the basic reserves were 16000T. The countries with more reserves were China, Peru, the United States, Canada and Russia. Their reserves accounted for about 81% of the world's total. China's reserves were the richest, but only about 8000t. Some data also said, China's reserves exceed 12kt; "Scattered" refers to the dispersed distribution of indium in the earth's crust. Although there are five independent minerals (hematite, copper molybdenum, cassiterite containing copper, lead and zinc, and wolframite, etc.), they are very rare in nature, and indium is mostly dispersed in other elemental minerals in the form of impurities, with more than 65% dispersed in lead-zinc ores. Indium is one of the dominant resources in China, and its distribution is also relatively concentrated, mainly in Yunnan, Hunan, Qinghai, Inner Mongolia and Guangxi

indium is a new bright blue spectrum discovered by German chemists ICH and chter in 1863 when they studied the spectral analysis of zinc oxide containing solutions in zinc mine, and then separated a new metal. They named this metal indium according to Latin blue (indium) and transliterated "indium" in Chinese

indium is a silvery white metal with metallic luster. Its texture is soft, and obvious marks can be made with fingernails; Density 7280kg/m3 - 7362kg/m3; The melting point is low, 156.6 ℃, while the boiling point is very high, 2075 ℃ - 2100 ℃; The conductivity of indium is low, only 20% of that of copper, and the resistance temperature coefficient is 4.9 × 103, resistivity 8.5 Ω· m - 9 Ω· m; The linear expansion coefficient of indium brand with further expansion is almost twice that of copper; Indium has good plasticity and can be processed into various semi-finished products; Its crystal structure is face centered tetragonal. When indium is used to rub another substance, it will be adsorbed on that substance, which shows its low hardness. The average thermal conductivity of indium at 0 ℃ - 100 ℃ is 80.0w/(m · K)

the atomic number of indium is 49, which is the fifth period III of the periodic table α An element of the group, which belongs to the same group as boron, aluminum, gallium and thallium. It is very stable in the air, will not oxidize, and can still maintain a silvery metallic luster. It can be slowly dissolved in cold dilute acid, but it will be violently dissolved in hot acid or concentrated acid. Generally, indium does not react with boiling water or alkaline solution. Indium powder ECM should use connective electrolyte that can produce reversible electrode reaction. Indium was electroplated in sulfate, fluoroborate and amino acid sulfonic acid solution. Indium can form binary, ternary, quaternary or more multicomponent alloys with many elements. Usually, adding a small amount of indium to many alloys can harden their surfaces and improve their strength and corrosion resistance. 9. Find out the resonance relationship between parts, structures, packaging and transportation processes

indium itself is harmless to human body and has no irritating effect on skin. General health protection measures can be taken in production, but it can not be used in the catering industry. Soluble indium compounds have certain toxicity. For example, indium phosphide can cause cancer, which was listed as a dangerous chemical by the European chemical Commission in January 2010

uses of indium

indium is known as the "vitamin" of alloys. Adding a small amount of indium to some alloys can improve some properties. The purity is 99.97% in. It is the main alloying element in the preparation of silver lead indium bearing alloys for high-speed aeroengines. Indium can raise the lifting seat 6 to the appropriate position (that is, the measured spring can be placed between the two pressure plates or between the upper and lower hooks) is an important addition element of meta lead solder. For example, indium can be used to replace the lead in the famous wood alloy. Each addition of 1% in can reduce its melting point by 1.45 ℃. When it is added to 19.1%, the melting point can be reduced to 47 ℃. The service life of bearing alloy containing indium is three or four times longer than that of alloy without indium. Indium containing alloys with low melting point have been widely used in fire protection equipment and thermal control equipment for circuit breaker protection equipment and automatic control system

alloys containing 50% indium and 50% tin are good vacuum sealing materials, which can be bonded to glass or glass metal; Gold, palladium, silver and copper alloys containing indium are excellent materials for dentistry and ornaments. Because indium has quite strong light reflection ability and anti-corrosion ability, it is a superior material for manufacturing ship reflectors. Indium is very sensitive to neutron radiation and has become a master of dose monitoring materials in the atomic energy industry

indium is a good additive for batteries and a superior corrosion inhibitor for mercury free alkaline batteries, making the battery a popular green environmental protection product. Indium has a magical effect in preventing the formation of glass atomization layer. Coating a thin layer of transparent indium on automotive glass can not produce atomization layer under any circumstances, and has been widely used in the field of high-end automotive glass, It will also have a certain application prospect in glass aspects such as commercial buildings and residential villas

indium and its compounds are widely used in the field of optoelectronic devices and semiconductor equipment, such as indium antimonide (InSb), indium phosphide (INP), indium arsenide (InAs) and other famous semiconductor device materials. In particular, indium phosphide has been effectively and widely used in optical fiber communication, laser light sources and heterojunction solar cells. It is an excellent solar cell film material with the advantages of high conversion rate, low cost, easy to carry, simple manufacturing process and so on; Indium antimonide and indium arsenide also have indispensable and important applications in infrared detection and optomagnetic device manufacturing. LED light source is also an important range of indium applications

the above are only all aspects of the application of indium and its compounds. At present, indium tin oxide (ITO) is the most consumed indium. In 2016, about 78% of indium produced worldwide was used to prepare this oxide film for the manufacture of various flat panel display screens. Even if silver display screens are widely used in the future, ITO display screens will not disappear

extraction of indium

China is the hometown of indium and a major indium producer. Yunnan Province is a key area for indium resource development and production in China. Generally, the extraction process of indium can be divided into four stages: first, it is enriched in the smelting process of major heavy non-ferrous metals and recycled as a by-product of comprehensive utilization; The second is to produce indium enrichment; Third, crude indium is produced through various chemical metallurgical processes; Fourth, electrolytic crude indium to obtain 4N (99.99%) fine indium. At present, the main process for extracting indium in the world is extraction electrolysis method, and its principle process flow is: raw materials containing indium → enrichment (indium content should be ≥ 0.002%) → leaching → purification → extraction → back extraction → zinc (aluminum) replacement → sponge indium → electrolytic refining → refined indium

at present, the extraction, semi-finished product processing, use, recycling and regeneration of indium has become a very effective circular economy, which is fully mature. In 2006, the global output of regenerated indium has exceeded that of primary indium. More than 75% of the former is recycled with new waste, because 78% of the global indium was used for ITO target village preparation in 2016. When preparing the target, the utilization rate of ITO is very low, only 20% - 30%. The rest is the extracted new waste, containing 39% - 55% indium, 2.25% - 3.15% tin, and trace impurities such as copper, silicon, iron, etc

there are new and old waste materials for recovering and regenerating indium. The new refers to the process waste during the production of target materials and the remaining target materials for the production of ITO conductive films. The old waste materials refer to indium containing electronic products with expired service life, such as LCD screens, but the new waste materials dominate. China has mastered the mature waste target recovery technology, but the production technology of ITO target materials still lags far behind that of industrial developed countries

at present, the ITO target production technology of five Japanese enterprises, South Korea SamSung company, Belgium meimeike company, American indium company, Germany Holly's company, etc. ranks in the forefront of the world, but Japan's energy companies, Dongcao company, Tonghe company, Mitsui company and Sumitomo company not only have the largest output, accounting for about 85% of the world's total output in 2016, but also have a good grasp of production technology, Samsung's output accounts for about 12% of the world's total output, while other companies account for only 3%

at present, China can only produce medium and low-end ITO targets, and most of the high-end targets are imported from Japan, although since 1994, Huaxi Group Co., Ltd. and Zhuzhou smelting Group Co., Ltd. have