In recent years, with the development of thin film solar energy as a national strategy, the thin film solar energy subdivision technology route of copper, indium, gallium and selenium (CIGS) has attracted great attention of the industry. This also brings a problem: the small metal "indium" needed for the production of copper-indium-gallium-selenium batteries is not very high in energy storage and production. This has caused some people in the industry to worry about whether indium will become a major "bottleneck" affecting the development of thin film batteries.

Indium is not easy to exploit, and people worry about its shortage of supply and unstable prices. However, if we study them carefully, we will find that these excessive worries are groundless, and the supply and demand of indium has entered a relatively stable period.
Indium, atomic number 49, was discovered in zinc concentrate by H. Richter, a German chemist, in 1863. It is a rare metal. Indium is silver white with a slightly bluish tinge. It is very soft and can be nicked with nails.
Indium metal is mainly used for manufacturing low-melting alloys, bearing alloys, semiconductors, light sources and other raw materials. Among them, the amount of ITO target used as transparent electrode coating accounts for about 70% of the amount of indium, and the annual demand is about 200 tons. With China's ITO target production occupying the domestic market and heading for the world, it is expected that the future demand for indium in China's ITO target field will exceed 700 tons per year.
In nature, indium minerals are dispersed in trace form and associated with other minerals. The distribution of indium in the crust is relatively small, which is 1/8 of gold and 1/50 of silver. So far, no single or indium-based natural indium deposit has been found.
According to statistics, the global proven indium reserves are estimated to be 50,000 tons, of which 50% can be exploited. Indium metal is produced by purifying waste zinc and tin in industry. The recovery rate is about 60-70%. From this calculation, on the basis of the proven reserves, the increase of recoverable amount and the non-improvement of indium recovery rate, about 15,000-18,000 tons of indium can be used at present.
"If the 18,000 tons of indium can be used, the total production of copper, indium, gallium and selenium batteries can produce 1,800 gigawatt. Even if only one tenth of the amount is used to produce copper, indium, gallium and selenium, 180 gigawatt can be produced. As far as the current production capacity of copper, indium, gallium and selenium is concerned, the indium resources are very rich. At present, indium does not constitute an influence on the application of copper, indium, gallium and selenium. In an interview with reporters, the relevant R&D personnel of National Energy Group calculated such a simple account. The researcher also said that the reason is that the application scale of copper, indium, gallium and selenium is not enough to touch the relationship between supply and demand of indium.
At the same time, copper, indium, gallium and selenium enterprises can also reduce indium consumption by technical means: through the development of new plasma spraying target technology, target spraying loss and indium recovery on residual target, solid waste indium recovery from coating, chip recovery and other means, indium market demand can be greatly reduced. In addition, the amount of indium can also be reduced by properly increasing the composition of gallium and thinning the cell film in copper-indium-gallium-selenium batteries. It is estimated that the conversion efficiency and productivity of copper, indium, gallium and selenium chips can be steadily improved, and the demand for indium consumption can also be reduced by about 15%.
With the development of copper, indium, gallium and selenium technology, the conversion efficiency, productivity and recovery technology improved, the net consumption of copper, indium, gallium, selenium and indium of 1 gigawatt will be reduced to less than 10 tons, while the medium-term target is 5 tons/gigawatt-6 tons/gigawatt. In addition, the industry generally believes that with the improvement of mining technology, drilling technology, purification technology and recycling technology, more and more indium resources can be used and proven reserves will gradually increase.